Friday, December 25, 2009

10 Human Experiments of 2009 – Year in Review

10 Human Experiments of 2009 – Year in Review
One of this year's big themes among bloggers was vitamin D deficiency. (Photo by Gail S)

Only a few days left until the end of the year, which means it's time to take a look at the inhuman experiments of 2009. For a summary of the experiments of 2008, click here.

1. Maca root experiment

The purpose of this experiment was to see whether taking maca powder increased energy and sex drive. While those who sell the stuff claim that maca is the ancient Incan remedy for just about every problem you can imagine, the scientific evidence behind it is more modest. That said, a couple of studies have indeed shown improved libido and increased sperm count from maca, so the claims are not entirely baseless.

Personally, I didn't notice anything different on the days I took maca, even in large doses. I speculated in the experiment conclusion that perhaps maca is only effective in those whose sex drive and energy levels are low to begin with. Another possible reason suggested by one of the studies is that only red maca is effective while yellow and black maca are not. The maca powder I purchased was yellow.

2. Retinol cream experiment

The retinol cream experiment was quite unique in the sense that it's one of the very few experiments that actually gave a positive result. The goal was to see whether retinol, the animal form of vitamin A, would improve skin quality. Since retinol is less harsh on the skin than retinoids, I thought it would be useful to try a retinol cream before moving on to the stronger stuff.

While the appearance of my skin didn't change visibly during the experiment, there was an unexpected growth of new hair on my left temple. I even took a few pictures to show I wasn't making it up. I'm not sure whether the effect was simply due to increased collagen production and skin cell proliferation or something else, but if you're suffering from hair loss, I would recommend giving retinol a go. As another experiment, I'm currently applying tretinoin on my face to see if retinoids are even more effective.

3. Tocotrienol experiment

Like tocopherols, tocotrienols are a form vitamin E. Most multivitamins contain only alpha-tocopherol, but it's the tocotrienols that seem to have all the interesting health benefits. Well, at least potential health benefits. One study reported an increase in hair growth in all subjects taking the tocotrienol supplement. Such a result seemed so unbelievable that I had to try it out for myself.

One major problem with this experiment was that tocotrienol supplements are not cheap, which meant that the duration of the experiment was only two months. As I wrote in the conclusion, I didn't see a visible increase in hair growth, but there appeared to be a reduction in the number of hairs lost daily. If I get my hands on an affordable tocotrienol supplement, I look forward to repeating the experiment to see if the reduction was due to tocotrienols or something else.

4. Topical vitamin C, vitamin E & ferulic acid experiment

In this experiment, I applied a topical consisting of ascorbid acid, vitamin E and ferulic acid on my face. All three compounds have some evidence behind them showing that they increase collagen production and improve skin quality. The product I was testing was called SkinCeuticals CE Ferulic acid, which is really expensive if you buy it the usual way; I purchased several smaller sampler bottles online, which was cheaper. Another way to save cash is to make a similar product yourself.

In the experiment conclusion I reported that I didn't see any improvement in my skin quality. A possible reason is that some of the liquid in the sampler bottles was apparently oxidised, which would render it useless. I concluded that it was not worth the price to keep using the product. However, some months later I read a book on skin aging that made me reconsider the whole thing, and so I decided to re-visit the experiment and order another set of sampler bottles. The experiment is still going on, and so far, none of the samplers have contained oxidised liquid.

5. Vitamin D3 experiment

As I'm sure you've noticed, vitamin D3 was really big in the health blogosphere this year. After reviewing the data I concluded that I've very likely been deficient in vitamin D3 for most of my life and decided to start supplementation. I know standing naked in the sun to get the required dosage is a big thing in the paleo circles, but at these latitudes it's not very feasible. Besides, sun damage seems to be a major cuplrit in skin aging.

For a few months, I took 2,000 IU per day and then increased to 5,000 IU. This got my serum 25-hydroxyvitamin D levels up to 113 nmol/L (45 ng/mL), which is in the optimal range. I'm still taking 5,000 IU daily, and while it hasn't given me complete immunity against all infections, this is the first experiment that has resulted in a reduction of colds. Not even intermittent fasting or the paleo diet did that.

6. Hyaluronic acid experiment

In a sort of continuation to my experiment with MSM, chondroitin and glucosamine, I decided to try oral supplementation with hyaluronic acid. Despite the high price, hyaluronic acid seems to be quite popular and is said to improve skin quality and promote hair growth. The evidence for oral supplements is shaky, however, except maybe for joint problems.

Because hyaluronic acid is so damn expensive, the experiment lasted for only a month, which is probably the shortest duration of any experiment on this blog. I didn't see any difference in skin quality or hair growth, but feel free the take the results with a grain of salt. I think hyaluronic acid may actually be quite useful, but next time I'd rather try applying it topically.

7. Tea tree oil vs. Korean red ginseng experiment

Now here was an experiment that seemed to go on forever. In this "classic" hair growth battle, Korean red ginseng and tea tree oil fought it out on my legs. Since Korean red ginseng (also known as Panax ginseng) has been shown to promote hair growth, and tea tree oil is supposed to be anti-androgenic, I was expecting ginseng to increase and tea tree oil to suppress hair growth on my legs.

After meticulous experimentation with various carrier oils and different parts of the body, I got sick of the whole thing and called it quits without ever seeing any results. You can read the "exciting" conclusion if you're interested in the details. All in all, I would think twice before adding these two to a hair loss regimen.

8. Intermittent fasting experiment

A couple of months ago I wrote on the blog that a year had passed since I began my intermittent fasting experiment. While I've occasionally experimented with different variations of the same thing, I have mostly followed the 24/24 hour cycle of feasting and fasting. That is, for most of the year I stopped eating at about 6 PM and then started eating again the next day at 6 PM.

After the last post describing my year on the diet, I've slowly returned towards a more "normal" way of eating again. Compared to other people, I still have lengthy periods of not eating, but I'm no longer on the strict 24-hour cycle. The main reason for the change is that intermittent fasting does not appear to increase lifespan like caloric restriction does, and life extension is my main interest, after all. For losing weight and improving insulin sensitivity it still appears to be beneficial, provided you do it the right way.

Beyond weight loss, however, I'm thinking there are better ways to incorporate fasting into my health regimen than the 24-hour cycle. Perhaps longer fasts done less frequently, perhaps periodical protein restriction. I'll write more about the subject once I do some more reading. Anyway, I feel pretty good about being able to follow my intermittent fasting routine so strictly for an entire year. Life extension or not, it surely taught me to think of hunger in a new, more positive way. The looks and comments I got from family members, friends, and strangers alike were pretty entertaining, too.

9. Emu oil vs. Hair Again experiment

This experiment was another battle between two hair growth products. This time the competitors were emu oil and a topical gel called Hair Again. Emu oil comes up every year in hair loss forums, but the fact is that the evidence behind it is very limited, to say the least. The commercial product, on the other hand, contained many ingredients that looked quite useful.

After eight months, I concluded that the battle had no clear winner, since there was no change on either side of my face. Yes, the hairs I grew with the retinol were still there, but no further improvement was seen. I still have some of the emu oil left, but I haven't found much use for it ever since I ran out of the topical gel. Sadly, even if I wanted to continue the experiment I couldn't, because the company that makes the gel refuses to ship to Finland any longer.

10. Nootropic experiment

The purpose of this three-way battle between taurine, acetyl-L-carnitine and ginkgo biloba was to see if any of them were effective as nootropics, either taken alone or in combinations. My subjective evaluation of my energy levels, mood, and ability concentrate would serve as the indicators. As an objective measurement, I compared my scores in a memory game meant to improve IQ.

For all the money I spent on these supplements, it's a bit of a disappointment that none of them seemed to do anything for me. As I wrote in the experiment conclusion, one possible reason why ginkgo didn't work is that the plant extracts may differ significantly among brands. Acetyl-L-carnitine and taurine, on the other hand, should be pretty much the same stuff regardless of the manufacturer. In the future, I may try another brand of ginkgo, and I'm thinking of using taurine to prevent glycation and hangovers. Further experiments may follow.

Conclusion

So there you have, the ten inhuman experiments of 2009. Once again, not many positive results, but hey, at least we've learned something, right? As you can see in the top-right corner of the blog under "Current Experiments", many of the experiments that started this year will continue into 2010, so stick around and see how they end.

Finally, I'd like to thank all the readers for your encouraging comments and questions during the past year – and for pointing out the mistakes, of course! You've been very helpful in making this blog better, and I hope the improvement continues the next year. Until then, happy holidays and take care!

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Wednesday, December 9, 2009

Nootropic Battle Conclusion: Acetyl-L-Carnitine vs. Ginkgo Biloba vs. Taurine

The search for ways to improve cognition and mood continues.
The search for ways to improve cognition and mood continues. (Photo by mtungate)

For the past several months, I've been experimenting with these three supplements to see if they have an effect on cognitition and mood. Many people report good effects, and there is some scientific evidence to support these claims.

However, because of the nature of the medicine business, most of the studies have been done either on animals or on people suffering from a disease such as Alzheimer's. The use of these supplements as nootropics in healthy people is therefore something of a grey area.

The idea of the experiment was to find out if they might increase mood, energy or cognitive performance using myself as the test subject. Below is a description of my experiences with each of the supplements along with a quick summary of the science behind their use.

Taurine

Taurine is added into many energy drinks, but the evidence behind its effectiveness is very limited. In mice, fairly low doses of taurine have been shown to either increase or decrease social interaction and anxiety, whereas in humans data is virtually non-existent except as a treatment for alcoholism.

In my own experiments, I did not see any effect from taking taurine. The recommended amount on the label is 675 mg between meals or at bedtime; my own intake varied between about 200 and 2400 mg. I tried taking it before meals, with meals, and after meals. The only time I thought I noticed something was when I took it before going to bed and had more vivid dreams than usual, but I was unable to reproduce the effect later on.

The potential benefit for preventing hangovers still intrigues me, so I may continue to take taurine in the future. However, I actually did take some taurine once after drinking, and unlike I usually do, did not drink much water before going to sleep. I woke up with a headache, so if it is effective, it's not a miracle drug.

Acetyl-L-carnitine

Carnitine in its various forms has quite a bit of scientific evidence behind it for use as a nootropic. Both L-carnitine and acetyl-L-carnitine help rodents perform better in maze tests and protect them from age-related cognitive decline. Elderly people seem to benefit from carnitine too, especially with higher doses. One study reported a nootropic effect even in young, healthy people.

This was the supplement I was expecting the best results from, but alas, it didn't have any effect on me. The doses used in human studies usually range from 1 to 3 grams; my own intake varied between 500 mg and 3,000 mg. Like in the case of taurine, I tried it during various times of the day. Most people suggest it should be taken away from meals, which is what I did towards the end of the experiment.

There was one time when it seemed that a higher dose resulted in suppression of hunger, but as I was unable to reproduce the effect, I concluded that it was due to something else. Indeed, one of the potential side effects of carnitine is an increase, not a decrease in appetite.

Another time when I thought I noticed an effect was when I took about a half an hour before going for a run. This was towards the end of a fast, and I felt more energetic than usual while running. There is some evidence that L-carnitine may increase aerobic performance, but since later attempts didn't produce similar results, I assume that the increased energy I felt was simply due to variations in the hunger cycle of intermittent fasting.

Although I feel that carnitine may have some long-term benefits for preventing cognitive decline, I find the price too high for me to keep supplementing with it. If I were to take it, however, I would go for bulk powder instead of capsules to save some cash.

Ginkgo biloba

Even though ginkgo biloba has been studied quite a bit, the results are inconclusive. It seems that gingko biloba does have a neuroprotective effect. In addition, it may reduce anxiety and prevent cognitive decline in elderly people.

The standard dose used in many studies is 120 mg, but doses two or three times as large are not unheard of. Comparing doses and ginkgo biloba supplements is difficult, because the extracts can be standardized differently. In my own experiments, I took between 60 mg and 360 mg at various times of the day.

This was perhaps the one supplement that had me wondering the most whether I was experiencing placebo or an actual effect from the pills. I often took 2-4 capsules (with 60 mg each) of ginkgo before going out, and sometimes it seemed like it gave me an energy boost. On the other hand, it may well have been due to other things, such as the caffeine from coffee or yerba mate. Indeed, taking only ginkgo biloba produced very inconsistent results: sometimes I thought I felt more energetic, other times I definitely didn't notice anything.

Anecdotal evidence suggests that some brands of ginkgo may be more effective than others, probably because of differences in the extraction methods. The price of ginkgo biloba is generally not terribly high, so I may experiment with other brands in the future.

Conclusion

In my own experience, none of the three supplements mentioned above produced significant and consistent results in terms of mood, energy or cognitive enhancement. As I mentioned at the beginning of the experiment, I also tried various combinations of the three, but this did not change the fact that for me, they were ineffective. This is based on both my own subjective evaluation and my scores in a memory game that I use to rate my concentration.

For the record, the supplements used in the nootropic battle were: Nu Health Ginkgo Biloba, Source Naturals Taurine, and Doctor's Best Acetyl-L-Carnitine.

Based on these results, I'm beginning to think that my susceptability to the placebo effect is fairly low. I don't necessarily mean that's a good thing, either – an imagined increase in mood or energy levels is just as good as an objectively measured increase, right? On the other hand, it probably does help me weed out the things that have a measurable effect on most people. Caffeine taken on an empty stomach still remains the unbeatable nootropic in my books.

If you have tried taurine, carnitine or ginkgo biloba (or any other nootropic), feel free to drop a comment and share your experience. Meanwhile, for more information on cognition, see these posts:

Green Tea Protects from the Psychological Effects of Stress in Rats
Caloric Restriction Improves Memory in the Elderly
Moderate and Severe Caloric Restriction Alter Behavior Differently in Rats
Anti-Aging in the Media: Rolling Stone on Ray Kurzweil

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Wednesday, November 25, 2009

5 Simple Exercises for Correcting Anterior Pelvic Tilt

Anterior pelvic tilt
A model performing a variation of the lower back stretch. (Photo by TerenceKearns.com)

Anterior pelvic tilt may sound like some horrible bone disease, but it's actually a fairly common problem with posture. In fact, according to some fitness people and gym teachers, it may even be the most common postural deviation.

What is anterior pelvic tilt?

In anatomical terms, "anterior" refers to the "front" side of the body (the side your face is on), and "pelvic tilt" means that the pelvis is tilted to one side. In this case, the tilt is towards the front, like in the image below:


Anterior pelvic tilt
As you can see, the spine is naturally slightly curved, but in anterior pelvic tilt the curve is excessive compared to a neutral posture. According to some physiotherapists, a desirable tilt is 0-5 degrees in men and 7-10 degrees in women. You can estimate your tilt by standing with your back against the wall and measuring how much space is between your lower back and the wall. If you can fit one hand in there you're fine. If you can fit a couple of wine bottles you're in trouble.

But what exactly is the problem with the anterior pelvic tilt? Well, for one thing, it doesn't make your posture look very good – at least not if you're a guy. If you're a woman, you may be able to pull it off. An arched back is considered a feminine trait, after all. Still, there's no need to go overboard, because the second reason to avoid (excessive) anterior pelvic tilt is that it causes lower back pain, especially with old age. Besides, a protruding belly doesn't look good on anyone.

Identifying the muscles that need fixing

There are several good articles out there with intricate anatomical descriptions of the interplay between muscles related to pelvic tilt, so I'll skip the details here and just give a brief overview. The gist is that not using certain muscles eventually causes other muscles to overcompensate, which leads to some muscles becoming lengthened and weak and other muscles short and stiff.
Here's a list of things that typically lead to anterior pelvic tilt (or characteristics of anterior pelvic tilt; it's difficult to say what causes what):
  • Lengthened (weak) hamstrings
  • Lengthened (weak) abdominals
  • Lengthened (weak) glutes
  • Shortened (tight) erector spinae
  • Shortened (tight) hip flexors
Hamstrings are the long thick muscles on the back of your legs that flex the knee and extend the hip. Abdominals are the muscles around the torso. While the outermost muscle (rectus abdominus) is responsible for that six-pack look, it's the deeper muscles that have the biggest effect on posture. Glutes are simply the butt muscles.

The erector spinae (or spinal erectors) is a group of muscles in the back that supports the spine. Finally, hip flexors are a group of muscles near the pelvis that move the hip forward during walking and running.


Exercises for correcting anterior pelvic tilt

To fix the problem and bring the pelvic tilt back to normal levels, a set of exercises that target these issues is needed. In essence, we need to do two things:
  1. Make the hamstrings, deeper abdominals and glutes stronger
  2. Stretch the spinal erectors and hip flexors
There are numerous exercises that can be done to achieve these ends, and quite possibly the most effective ones are those that also involve weights and gym equipment. However, there are also exercises that you can do at home using only your body weight. It's these exercises we'll be looking at next.

Exercise 1: Glute bridge

This exercise, also known as supine hip extension or pelvic lift, strengthens both the glutes and the hamstrings. Here's the basic way to do it:


One variation of the exercise is to straighten one leg so that only one foot is on the ground, hold for a while and then do the same with the other leg.

Exercise 2: Front and side plank

Plank exercises are good for making the abdominal muscles stronger. In contrast to sit-ups, which mainly affect the superficial muscles, planks target the deeper muscles. In addition to the usual front plank where both feet and elbows are on the ground, you can do side planks:


This exercise can also be made more difficult by lifting one of the legs up and holding for at least 30 seconds.

Exercise 3: Lunge stretch

The lunge stretch exercise stretches the hip flexors. It's also called by various other names like hip flexor lunge, lunging hip flexor stretch, psoas stretch, etc. Depending on who you ask, you may get a different answer as to how to perform the exercise, but here's one way:


This exercise can also be done as a forward lunge, in which you begin from a standing position and then lunge forward and drop your hips towards the floor. Performed this way, you'll target glutes and hamstrings more than the hip flexors, unless you also do the stretch.

Exercise 4: Lower back stretch

The lower back stretch is an exercise that stretches the erector spinae. It's also known as all fours back stretch, back arch stretch, cat pose stretch, and various other names. Here's how to do it:


You can alternate between the two arches as seen in the video, but keep in mind that it's the upward arch that stretches the erector spinae.

Exercise 5: Supine pelvic tilt

Finally, here's an exercise imitating what you want to happen through all your hard work. Like planks, the supine pelvic tilt mainly targets the deeper abdominal muscles. Here's a good example of how to do it (nevermind the Swedish subtitles):


The exercise itself is very subtle, but it gives a good idea of what you're trying to achieve. You can alternate between short reps and holding the tilt for a longer period.

Summary and my experiment

The muscles that are required to maintain a natural posture don't get enough exercise during daily routines, especially if you work at a desk job. This causes some muscles to weaken and others to compensate. As a result, the pelvis tilts forward, which in turn results in a postural problem known as anterior pelvic tilt. Many people have some degree of (excessive) anterior pelvic tilt, whether or not they realize it.

There are several exercises that can be performed to train the muscles that are weakened (hamstrings, deeper abdominals and glutes) and stretch the ones that are overcompensating (hip flexors and the erector spinae). You may get better and faster results by combining many different exercises, but the ones shown here will get you started.

Personally, I recognize my posture from the first picture showing excessive anterior pelvic tilt. I also have occasional problems with pain in the lower back. Until now, I haven't really known what the precise issue with my posture was, but thankfully, I was pointed in the right direction by some members of the imminst.org forums.

So for my newest human experiment, I'll be doing these exercises (and possibly others as I discover them) at least three times a week and seeing whether I can fix my anterior pelvic tilt. Meanwhile, if you have suggestions for other and/or better exercises, please drop a comment and share them!

For more information on exercise and health, see these posts:

L-Carnitine, Exercise Performance & Oxidative Stress
Green Tea Extract Increases Insulin Sensitivity & Fat Burning during Exercise
Green Tea Extract Enhances Abdominal Fat Loss from Exercise
Coenzyme Q10, Exercise and Oxidative Stress

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Wednesday, November 18, 2009

Alternate-Day Feeding and Weight Loss: Is It the Calories Or the Fasting?

Intermittent Fasting and Weight Loss: Is It the Calories or the Fasting?
Weight loss with one slice of pizza one day and anything you want on the next? (Photo by nettsu)

I don't know if you noticed, but a new study on intermittent fasting recently made headlines in several media. The paper basically found that alternate-day fasting (or "on-off fasting" as it was named in some articles) helped obese adults to lose weight.

That's not a huge surprise, really. If you're obese, it means you eat too much of the wrong foods and probably too often. Fasting every other day means you'll at least be eating them less often, if not less per se. However, the conclusions that have been drawn in various articles from the study seemed a little suspicious to me, so I decided to read the whole paper.

Indeed, the authors themselves appear to be somewhat confused as to what really caused the weight loss. So without further due, let's take a closer look at what the study actually found (link).

Study design

12 obese women and 4 obese men were recruited for the study. Mean age was 46 years, mean body weight was 96.8 kg, and mean BMI 33.8. Not exactly the featherweight league.

The study consisted of three phases. The first one was a 2-week control phase, during which the subjects were told to maintain their usual weight by eating and exercising as they normally would. In the second phase, which lasted for 4 weeks, all participants were given a standard menu containing 25% of their baseline energy needs on the fast days. On the feeding days they could eat as much as they wanted. The third phase, also 4 weeks, was similar to the second one. The only difference was that the participants could choose what they wanted to eat on their fasting days, as long as they only ate 25% of their baseline needs.

So, the first thing that sets this study apart from how most people do intermittent fasting is that they didn't consume zero calories during their fast. They just ate significantly less. The second thing is that the fasts began and ended at midnight. Most people (including me) start and end their fast sometime during the day, because it allows them to eat at least once a day. If the participants went to sleep before midnight, their "fasts" were significantly longer than 24 hours.

Their standard diets were also less than optimal in my opinion. Things like chicken fettucini, vegetarian pizza, chicken enchilada, cookies, and crackers aren't exactly paleolithic foods consistent with the idea of intermittent fasting. But then, this wasn't a paleo study, which explains why they were fed high-carb, low-fat foods. For the third phase, they were given diet tips by a registered dietitian:

On the ad libitum food intake day, subjects were instructed to limit fat intake to <30%> dairy options.

So more carbs and less fat once again. They probably took some of this advice and applied for their feeding days as well, which makes me wonder if they wouldn't have lost even more weight had they opted for low-carb foods instead. Still, as you can see from the results below, they did manage to lose weight even with this diet.

Results

During the first phase, there was no weight loss. This is unsurprising, since all the participants just kept on eating whatever made them obese in the first place. During the eight weeks of alternate-day fasting they did lose weight, however.

In the second and third phase the subjects lost weight at a rate of ~0.7 kg per week. At the end of the study, they had lost about 5.6 kg, most of which was fat. Mean BMI decreased from 33.7 to 29.9, while body fat percentage dropped from ~45 to ~42%.

Cholesterol levels were also reduced as a result of alternate-day fasting. HDL remained the same, but LDL decreased by almost 25%. This to me is a more impressive result than the weight loss, which I think could've been greater with proper food choices.

Systolic blood pressure was lowered by 4.4 mm Hg, but diastolic blood pressure remained the same. Heart rates varied throughout the study, but at the end, they were about 4 beats per minute lower than in the beginning.

Discussion

Okay, so everyone lost some weight and improved their LDL/HDL ratio on this modified version of intermittent fasting. But what exactly is behind these results? The first thing that came to my mind as I was reading the paper was: how much were these people eating on their feeding days? Surely that would have a drastic effect on weight loss.

Unfortunately, there's no mention of this in the paper. Yes, they were told they could eat ad libitum, but apparently they were not told to keep a record of what or how much calories they ate when they were not fasting. I know food diaries are generally unreliable (people tend to underestimate how much they eat), but it would've been better than nothing. The authors seem surprised that the subjects lost as much weight as they did:

We predicted that subjects would lose a total of 4.5 kg fat mass after 8 wk (on the basis of a 75% decrease in energy intake on the fast day, with no change in energy intake on the feed day). The actual fat mass lost (5.4 kg) exceeded our predictions.

With no change in energy intake on the feed day? I'm not sure where the authors got the idea that when you eat very little on one day, the next day you won't be extra hungry and compensate. That's certainly not my experience. On the contrary, I fully compensate for any missed calories by just eating twice as much the next day. Certainly not compensating can be done if one wants to, which may be what happened here:

This indicates that these subjects were also limiting their energy intake on the feed day, which may have occurred because the subjects knew they were enrolled in a weight loss trial.

On the other hand, some articles in the media (such as this one) have reported that there was a slight compensation going on:

On non-fasting days people typically ate between 100 percent or 125 percent of their calorie needs.

This statement is probably from a press release by the authors, but the paper itself is silent on the issue. In any case, if you're eating 75% less on one day and only 25% more the next, you're still 50% short.

That, in effect, makes this a study on caloric restriction, not intermittent fasting. How is it surprising in any way that people who eat half (or even less) than what they're used to manage to lose weight? Isn't that obvious? The amount of weight they lost is pretty much what you'd expect on a low-fat, calorie-restricted diet. And based on other studies, if they'd eaten more calories but restricted carbohydrates, they'd have lost more weight.

The whole point of intermittent fasting is that you don't have to restrict your energy intake, you just don't eat all the time. If energy intake is the same and yet there are health benefits, then we can conclude that it's the fasting that is behind them. If, at the same time, calorie intake is restricted, there's no way of knowing whether it's the reduced calories or the fasting that is the cause. And of course, if intermittent fasting leads to a voluntary reduction in energy intake, that tells us something too.

I have a feeling that eating the small meal every other day magically resulted in no hunger in this study. They were probably consciously limiting their food intake even though they were told they could eat as much as they want. The fact that the authors actually expected the participants to eat only their usual calories on feeding days makes me even more suspicious.

Try eating 500 kcal on one day and then seeing how you feel the next day. If you typically eat 2,000 kcal, somehow I don't think 2,500 kcal is going to cut it. I know it doesn't for me, at least not in the long term. As for this diet being much easier to follow than old-school calorie restriction (which the paper seems to suggest), I doubt it.

For more information on intermittent fasting and caloric restriction, see these posts:

Intermittent Fasting: Understanding the Hunger Cycle
Slowing Down Aging with Intermittent Protein Restriction
Caloric Restriction Improves Memory in the Elderly
Intermittent Fasting Reduces Mitochondrial Damage and Lymphoma Incidence in Aged Mice

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Wednesday, November 11, 2009

The Long-Term Effects of Antibiotics on Health and Immunity

Garlic is the famous natural antibiotic.
Garlic is the famous natural antibiotic. (Photo by stijn)

This is the third and last installment in a series of posts on immune function and gastrointestinal health. Given that the swine flu is still making rounds around the world, learning more about how beneficial bacteria can ward off viral infections has been very useful at least for me.

So far, we've seen that foods and supplements containing probiotics can reduce the occurrence and severity of the common cold. Probiotics also have other benefits, such as protection from cancer and increased resistance to cancer. We've also seen that another way to increase beneficial bacteria in the gut are prebiotics, which are a form of fiber found in foods such as Jerusalem artichoke and chicory root. The combinations of prebiotics and probiotics are known as synbiotics and may be superior to either one alone.

Antibiotics and resistant bacterial strains

The one group of biotics that's left to tackle is antibiotics. Most people have probably gotten a prescription of antibiotics at least once in their life. Most people are probably also aware that antibiotics are prescribed way too frequently these days by many doctors, even for health issues that antibiotics can't relieve. As antibiotics only work against bacterial infections, not viruses, taking them for flu symptoms is useless.

The commonly known problem is that as the use of antibiotics becomes more and more widespread, the bacteria become more and more resistant. This is especially common when people quit their antibiotics prescription halfway through because they "feel fine"; some of the surviving bacteria then mutate into more resistant strains and spread into other people.

In a way, there is an evolutionary war going on between medicine and bacteria, and while antibiotics are a fantastic discovery and have many applications, their overuse is a serious problem. That's why taking antibiotics "just in case" is not a great idea long-term.

Other health problems from antibiotics

If the well-being of the rest of humanity doesn't bother you all that much, there are also other, less known reasons to stay away from antibiotics unless you actually need them. Let's look at some of the evidence showing the harmful effects of antibiotics.

Most of the negatives stem from the positive fact that antibiotics are so effective. The problem is that antibiotics are not as specific as we'd like: while they do destroy harmful bacteria, they also destroy beneficial bacteria. That's why it's never recommended to take probiotics at the same time with antibiotics, because the probiotics are just rendered useless.

Since one of the functions of intestinal bacteria is to aid in food digestion, it's no surprise that antibiotics can cause digestive problems. Diarrhea occurs in about 25% of patients receiving antibiotics (link). Probiotics, on the other hand, can counter some of this effect. At least Lactobacillus GG and Saccharomyces boulardii appear to be effective. As mentioned before, leave about 3 hours between taking antibiotics and probiotics to avoid killing the beneficial bacteria right away.

The effect of antibiotics may be especially pronounced in babies, whose bacterial colonies have not yet matured. In one study, rats who were given an antibiotic for 10-17 days saw a near complete eradication of Lactobacillus in the intestine along with a drastic reduction in other bacteria (link). This would obviously have a negative effect on immunity in general.

Another group to whom antibiotics may pose a real danger are the critically ill. One study showed that not only did the microflorarl biodiversity of patients in the intensive care unit significantly decrease with antibiotics, but there were also more organ failures and deaths in patients given antibiotics (link).

Antibiotics also seem to have a negative effect on phytoestrogens. The levels of the lignan enterolactone, a type of phytoestrogen, were significantly lower in men and women who had taken oral antibiotics up to 16 months before measurement (link). The reduction was associated with the number of treatments and time from last treatment. Although not life-threatening, this reduction should be of some concern to those who are taking for example flax lignans for hair growth or other health benefits.

Long-term impairment of immunity from antibiotics

If the above reasons didn't put you off antibiotics for good, here comes the worst part: the previously unknown long-term effects of antibiotics.

Until recently, the effect of antibiotics was thought to be temporary. As long as you took your prebiotics at least 3 hours after your antibiotics, you'd be fine. Any long-term changes in intestinal microflora were considered to last only a few months, after which everything would return to normal.

Unfortunately, some new studies have begun to show that this is not necessarily the case. A study funded by the Finnish Academy found that the earlier estimates were too conservative, and that the effects of antibiotics on intestinal bacteria were visible even after a year (link). Surprisingly, they also discovered that using one type of antibiotic (such as penicillin or tetracycline) increases the resistance of bacteria to other types of antibiotics as well. The old idea of switching to a different antibiotic to avoid resistance doesn't seem so good after all.

A study from last year confirms these findings. Using a novel method of observing the human gut microbiota, the authors found that antibiotic treatment "influenced the abundance of about a third of the bacterial taxa in the gut, decreasing the taxonomic richness, diversity, and evenness of the community" (link). While the conditions partly returned to normal after four weeks, several bacterial taxa failed to recover even after six months.

Conclusion

While antibiotics certainly have their uses, taking them when unnecessary can be harmful in many ways. Here's a summary of the negatives:

  • Increased resistance to antibiotics
  • Diarrhea and digestive problems
  • Reduction in beneficial phytoestrogens
  • Impaired immunity, especially in children and the critically ill
  • Long-term changes in gut microflora

Since antibiotics, by definition, are substances or compounds that kill or inhibit the growth of bacteria, it's good to keep two things in mind. First, antibiotics destroy not only bad bacteria but also good ones. Second, antibiotics are only effective against bacteria, not viruses. So before getting antibiotics for an infection, make sure it really is a bacterial and not a viral infection (the common cold, for example, is a viral infection).

For more information on health and immunity, see these posts:

Prebiotics, Synbiotics and the Immune System
The 7 Types of Aging Damage That End up Killing You
Intermittent Fasting Reduces Mitochondrial Damage and Lymphoma Incidence in Aged Mice
Swine Flu and Avoiding the Cytokine Storm: What to Eat and What Not to Eat?

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Wednesday, November 4, 2009

Teeth Whitening Experiment: Plus White 5 Minute Bleach Whitening Gel

Teeth Whitening Experiment: Plus White 5 Minute Bleach Whitening Gel
Do vampires dream of electric teeth?

It's been about three months since my last update on the teeth whitening experiment. This experiment is my attempt to find safe ways to whiten my teeth and keep gums from receding. Given that I drink copious amounts of green tea and coffee daily, the whitening part has proven rather challenging.

For those who haven't been following the blog for very long, here's a quick recap. The first toothpaste I tried was Beverly Hills Formula Natural White, which I found in a grocery store while abroad. On paper, this toothpaste had all the good stuff – including coenzyme Q10 and green tea extract – but I didn't really see any real results. For the next few months I turned to Colgate Sensation White with its "micro-cleaning crystals". Again, no visible whitening of the teeth.

After Colgate it was time to try an ordinary store brand. The product I tried contained a combination of hydrated silica and triglycerides, which were supposed to work together to remove plaque and whiten the teeth. Granted, my teeth didn't get any more discolored despite all that tea, coffee, dark chocolate, and turmeric, but still, they didn't get any whiter either.

So now, after discovering that none of these whitening toothpastes seem to have any real whitening effect, I've brought out the big guns. Or at least slightly bigger than those pathetic toothpastes. This product is called Plus White 5 Minute Bleach Whitening Gel (for sensitive teeth), which is not a toothpaste per se but a gel that you leave on the teeth for a few minutes.

The whitening effect of this gel is based on hydrogen peroxide, a common ingredient in DIY teeth whitening products, and best of all, a substance actually proven to whiten teeth. You could probably make a very similar gel at home if you got your hands on some hydrogen peroxide, but I took the easy way and ordered the product online (since they don't sell Plus White in Europe, at least not in Finland). With international shipping it was a bit costly, but if you live in the US, you can get this stuff for a few dollars in several retail stores.

The instructions say to apply the gel on the teeth twice a day and leave it on for five minutes. After two weeks of use, you can start applying it less often. I'm going to start by applying it once a day to track any possible whitening effects more carefully. I'll probably be too lazy to take pictures, though, as it's a hassle to get the lighting right to make any worthwhile comparisons of tooth color. But rest assured, once I see results (or once I run out of the stuff), you'll be the first to know.

I have to say this is the first teeth whitening product that I actually expect to work. But then, I've seen absolutely no effect from so many supplements I've experimented with that I won't be too surprised if it doesn't. I'm just worried that if this doesn't work, the next step is going be an expensive visit to the dentist.

For more information on oral health, see these posts:

Tea, Coffee and Cocoa: All Good for Your Teeth
Dental Health Effects of Green and Black Tea
The Role of Coenzyme Q10 in Oral Health
Preventing Mouth Ulcers with Tea Tree Oil Toothpaste - Results after Two Months

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Thursday, October 29, 2009

Prebiotics, Synbiotics and the Immune System

Bananas contain a small amount of prebiotics.
Bananas contain a small amount of prebiotics. (Photo by clairity)

Last week I wrote about the effectiveness of probiotics for improving gut health and immunity. While not all studies agreed they could ward off the flu, pretty much all of them found at least some positive effects on the immune system from taking probiotics.

As mentioned, probiotics are available as supplements and in some foods such as dairy products. But there's also another way of promoting healthy bacteria in the gastrointestinal tract: prebiotics. Prebiotics are non-digestible ingredients in food that stimulate the growth and activity of healthy bacteria inside the body. In a sense, prebiotics cause the body to produce its own probiotics.

What are prebiotics?

There is some disagreement in the scientific community over which substances are probiotics, but at the minimum this category includes oligofructose and inulin. Oligofructose is a fructooligosaccharide, which refers to a short chain of sugar (in this case fructose) molecules. Inulins are a group of polysaccharides, which means a long chain of sugar molecules.

Since these prebiotics are composed of sugars, they are carbohydrates, and since they are indigestable, they are fibers. Further, inulin and oligofructose are soluble fibers, meaning that they're able to dissolve in water. Though they can't be digested, they do undergo fermentation as the bacteria get their hands on them. At the same time, the microflora of the gut is affected.

As the bacteria metabolise prebiotics in the colon, significant quantities of carbon dioxide, hydrogen and methane are released, which means that eating foods with prebiotics can cause gas. With long-term consumption, as the body grows accustomed to inulin and oligofructose, this unpleasant side effect is reduced.

Food sources of prebiotics

Inulin and oligofructose are naturally present in many plant foods, but their quantities differ significantly. Here's a list of foods in decreasing order of their average prebiotic content (values per 100 g [link]):

  • Chicory root: 41.6 g inulin, 22.9 g oligofructose
  • Jerusalem artichoke: 18.0 g inulin, 13.5 g oligofructose
  • Dandelion greens: 13.5 g inulin, 10.8 g oligofructose
  • Garlic: 12.5 g inulin, 5.0 g oligofructose
  • Leek: 6.5 g inulin, 5.2 g oligofructose
  • Asparagus: 2.5 g inulin, 2.5 g oligofructose
  • Wheat bran: 2.5 g inulin, 2.5 g oligofructose
  • Wheat flour, baked: 2.4 g inulin, 2.4 g oligofructose
  • Banana: 0.5 g inulin, 0.5 oligofructose

Note that unless stated otherwise, these figures apply to raw foods. Cooking in general seems to reduce content of prebiotics by 25-75%. Chicory root and Jerusalem artichoke (not to be confused with the globe artichoke, which is green in color) clearly take the cake. Even when cooked, these two plants still contain plenty of inulin and oligofructose.

Prebiotics and the immune system

Since probiotics have been shown to benefit the immune system, and prebiotics promote probiotic bacteria in the gastrointestinal tract, it makes sense that the consumption of prebiotics would have similar effects. Unfortunately, for those interested in preventing the common cold and other viral infections, not many studies have actually looked at whether prebiotics are effective. With that in mind, let's take a look at the evidence behind prebiotics and their effect on immune health in general.

There are some studies on humans showing that the consumption of prebiotics does modify the immune system (link, link). Specifically, prebiotics may reduce intestinal infections and intenstinal inflammation. On the other hand, inulin and oligofructose can also activate immune cells and increase the cytotoxicity of natural killer cells and the production of cytokines (link). In rats, prebiotics increase the number of T cells, interleukin-2 and interleukin-4, which indicates that prebiotics enhance the immune system (link).

One study found that a prebiotic galacto-oligosaccharide mixture was helpful in reducing travellers' diarrhoea (link). Those who got the prebiotic instead of the placebo had fewer incidences and less symptoms of diarrhoea when travelling to foreign countires. In infants, human milk protects from morbidity and mortality due to diarrhoea compared to formula milk, most likely because of the presence of prebiotic oligosaccharides in human milk (link). Some studies have also shown that prebiotics may help with irritable bowel syndrome (link), but the evidence is inconclusive. And, even though prebiotics may cause gas, they can also help with lactose intolerance (link).

A commonly cited example of the health effects of probiotic-containing foods is their anticarcinogenic activity. This is at least in part due to the stimulation of lactic acid producing bacteria in the colon, since lactic acid producing bacteria reduce the ability of microflora to produce carcinogens. Prebiotics seem to have a similar effect (link), possibly being even more effective than probiotics (link).

As for influenza, one study found that gamma-inulin, the active component of inulin preparations, improved the response to a variety of antigens in mice (link). When given a lethal dose of the influenza virus, all of the mice died, but when gamma-inulin was administered at the same time, half of them survived.

Synbiotics: even better than prebiotics and probiotics?

Synbiotics is the fancy name given to combinations of probiotics and prebiotics. The idea is that these two would work synergistically to produce even better results than either one would alone. Indeed, there is some evidence that synbiotics are superior to prebiotics and probiotics (link). In any case, the effect of synbiotics is different from that of pre- or probiotics (link).

Not all the studies are quite as promising, however One study found that rats fed prebiotics actually had a poorer resistance to salmonella than controls (link). This impairment was partially but not entirely prevented by calcium phosphate. It's not clear whether the same applies to humans, but it does emphasize the fact that we don't entirely understand how synbiotics affect the immune system.

Conclusion

While almost all studies have shown at least some benefit from probiotics, less is known about the effect of probiotics and synbiotics on the immune system. Prebiotics appear to increase the number and activity of probiotic bacteria in the body, but studies in humans and animals have yielded inconclusive results.

Sources of prebiotics, namely inulin and fructooligosaccharide, include nutritional supplements and plant foods. Compared to most commonly consumed foods with prebiotics, such as wheat and banana, supplements are often a better source. However, Jerusalem artichoke and chicory root are the best sources of inulin and fructooligosaccharide, containing much more than any supplement.

For more information on immunity and supplements, see these posts:

Enhancing Immunity with Probiotics: Can They Ward Off the Flu?
Swine Flu and Avoiding the Cytokine Storm: What to Eat and What Not to Eat?
Examining Possible Causes for Slower Wound Healing
How to Choose Between Different Forms of Coenzyme Q10: Ubiquinone vs. Ubiquinol

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Tuesday, October 20, 2009

Enhancing Immunity with Probiotics: Can They Ward Off the Flu?

Kefir is a natural source of probiotics.
Kefir is a natural source of probiotics. (Photo by uncle andrey)

I don't know if it's the swine flu or a normal influenza virus going around, but seems like everybody's been getting sick during the past few months. This particular virus is particulary resilient, with people being ill for weeks at a time.

I succesfully managed to avoid the flu for about a month, while just about everyone else was complaining about the cold that just won't go away. Feeling very pleased with myself, I put my exceptional immunity down to the optimal vitamin D levels I've achieved after supplementing with 5,000 IU per day. This really has reduced the frequency of colds, but it wasn't enough to save me from catching the same thing as everyone else.

So, having nothing better do to than to lie in bed feeling crappy, I thought I'd educate myself on the subject of curing and preventing viral infections such as the common cold. Given that a prescription for antibiotics (to treat an ear infection) oddly coincided with my falling ill, I was interested in whether probiotics might be of use. In this post, we'll take a look at the evidence behind probiotics and immunity.

What are probiotics?

Our bodies are host to trillions of microorganisms, most of which are good and some of which are harmful. Probiotics is the name given to some strains of bacteria (a type of microorganism) that are thought to promote overall health.

These bacteria either naturally exist in foods, or are used to fortify foods, or sold as supplements. Yoghurt, for example, may naturally contain live strains or bacteria, but there are also lots of yoghurts with added bacteria. The idea is that by consuming these bacteria, their proportion in the gastrointestinal tract is increased, which in turn will have benefits for health.

Probiotic bacteria play several roles in maintaining overall health. We probably don't know all the ways probiotics effect health, but here's a list of functions commonly cited in the literature:

  • Boosting the immune system
  • Limiting the growth of pathogenic organisms
  • Food digestion
  • Nutrient absorption
  • Protection from cancer
  • Allergy resistance

The function we're interested here is immune enhancement. Probiotic bacteria play a key part in immune function through a variety of mechanisms (link). For example, they increase the number of circulating white blood cells or leukocytes, which defend the body against infectious disease. They also increase levels of antibodies or immunoglobulins, which are used to identify and neutralize foreign objects like viruses and bacteria.

Can probiotics prevent the flu?

While the bacteria in the gastrointestinal tract clearly play an important role in immune function, it's far less clear whether probiotics consumed with foods or as supplements have any effect. Some product reviews have revealed that up to a half of the probiotic products studied may contain significantly less live bacteria than advertised. And even if they do contain the bacteria, will eating them enhance the immune function?

Well, at least pharmaceutical grade probiotic products seem to do the trick. In one study, healthy Swedish workers were randomised to receive either Lactobacillus reuteri or placebo for 80 days (link). In the placebo group, 26.4% reported being sick during this period, compared with only 10.6% in the probiotic group. These figures included only illnesses related to the respiratory and/or gastrointestinal tracts, so the probiotic treatment clearly improved their immune system. It was especially effective in those participants who worked the night shift.

In a 6-month study on children, probiotic consumption reduced both the duration and incidence of fever and cough compared to placebo (link). The probiotic strains used were Lactobacillus acidophilus and Bifidobacterium animalis. The combination of the two was better than L. acidophilus alone, reducing fever incidence by 72.7%.

Another study found that the cellular immunity of the elderly improved when the probiotic Bifidobacterium lactis HN019 was added into their milk (link). The authors note that the improvements were greatest in those participants who had poor immune systems before the treatment. Instead of measuring how often they got sick, however, the authors measured the proportions of T lymphocytes and natural killer cells, so it's not clear how this translated into overall health.

Indeed, not all studies have shown that probiotics can prevent you from catching a cold. One large study found that supplementing healthy adults with probiotic lactobacilli and bifidobacteria had no effect on the incidence of the common cold (link). It did, however, reduce the severity of symptoms and shorten their duration by almost 2 days.

Conclusion

Probiotic bacteria are known to play an important role in immune function. Less is known, however, about whether taking probiotic supplements can enhance the immune system and reduce the incidence of viral infections such as the common cold.

Based on the few studies that have actually looked into this, it seems that at the very least, long-term supplementation with probiotics reduces the duration and severity of the symptoms flu. Some of the studies also found that probiotics dramatically reduced the incidence of flu. Thus, there is a basis for the claim that probiotics can help prevent you from getting sick.

There's no evidence that taking probiotic supplements after you've gotten sick will do anything, however. It also appears that the effect of probiotic is greatest in those people whose immune systems are not working properly or are under a lot of stress.

Keep in mind that some of the foods with added probiotics may not actually contain any live bacteria, despite what it says on the label, since the bacteria die quickly unless the product is kept refridgerated. The same is true of supplements in capsule form, unless it specifically states that the product is stable in room temperatures. With powdered supplements, moisture is a potential problem.

For more information on supplements and immunity, see these posts:

L-Carnitine, Exercise Performance & Oxidative Stress
The Role of Coenzyme Q10 in Oral Health
Swine Flu and Avoiding the Cytokine Storm: What to Eat and What Not to Eat?
Examining Possible Causes for Slower Wound Healing

Read More......


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Thursday, October 15, 2009

5 Reasons Why Dark Chocolate Is Better than Milk Chocolate


Look good? Forget it, there's way too much sugar. (Photo by .craig)

You may have thought of chocolate as a guilty pleasure, but the ancient Maya considered it the food of gods.

Granted, the Maya also thought cutting out someone's heart in a ritual ceremony was a good fun, but they did get one thing right: chocolate really is a health food. That is, as long as you buy the dark kind. In fact, the darker the chocolate the healthier it is. As good as that sugar-laden milk chocolate bar may taste, it wouldn't have made its way into any self-respecting Maya feast.

If you don't believe me, read further for three good reasons to choose dark chocolate instead of milk chocolate.

1. Dark chocolate is better for weight loss.

Even though the amount of calories in milk chocolate and dark chocolate are pretty similar (and in fact milk chocolate sometimes contains fewer calories), dark chocolate contains significantly less carbohydrates. Milk chocolate usually has about 50 grams of carbs per 100 g, while the amount of carbs in dark chocolate ranges from 8 to 35 carbs, depending on how dark it is. A chocolate with 70% cocoa has ~30 grams; a 85% chocolate has ~20 grams.

If weight loss or maintenance is your goal, the combination of large amounts of carbohydrates and fat is something to avoid. A high carbohydrate load will increase insulin secretion, which is a signal for the body to store energy as fat. The reason why low-carb diets are so effective for weight loss is their effect on insulin: even if you eat lots of fat, if there are no carbs present to drive insulin up, the energy from dietary fat won't be stored into fat cells.

Unless you consume only a small quantity or restrict other carb sources to a minimum, combining milk chocolate with a low-carb diet is going to be difficult. If your goal is to stay under 50 grams per day, 100 grams of milk chocolate fills up your entire quota. But 100 grams of 85% dark chocolate still leaves you with 30 grams to spend on other carb sources, making dark chocolate a viable option even for low-carb dieters.

2. Dark chocolate causes less aging.

Okay, so perhaps a bit of an exaggeration there, since we don't know exactly how big a role advanced glycation end-products play in the aging process. We do know, however, that the accumulation of AGEs is one of the seven biomarkers of aging, which makes avoiding them a sensible goal.

As it happens, weight gain is not the only problem with the carbs in milk chocolate. Almost all of the carbohydrate in chocolate is sucrose, which is half glucose and half fructose. Even though the word 'glycation' in 'AGE' implies that glucose is the culprit, the fact is that fructose is much more prone to cause AGEs in the body. Since the main ingredient in milk chocolate is sugar, a 100 grams of milk chocolate will also give you a hefty dose of fructose.

Dark chocolate, on the other hand, is mostly composed of fat – cocoa butter, to be specific. The fatty acid composition is 61% saturated fat, 36% monounsaturated and only 3% polyunsaturated fat, making cocoa butter very resistant to oxidation. And if you're worried about cholesterol, here's something to ease your mind: almost all of the saturated fat in cocoa butter is cholesterol-neutral stearic acid. Fructose, however, may increase triglycerides levels.

Unlike dark chocolate, milk chocolate also contains some lactose. In addition to making milk chocolate an impossible treat for some lactose intolerants, lactose also causes glycation. Lactose breaks down to glucose and galactose, and like fructose, galactose appears to form AGEs more rapidly than glucose.

3. Dark chocolate has more cocoa polyphenols.

The health benefits of chocolate are almost entirely due to the polyphenols found in cocoa. As a rule of thumb, whenever you read something good about chocolate, what they're really talking about is cocoa. Therefore, as the cocoa content of chocolate increases, so do its positive effects on health. A standard milk chocolate will contain about 30% cocoa, while premium dark chocolates usually have more than 70%.

Another thing that reduces the polyphenol content of chocolate (by 60-90%) is alkalization (link), also known as Dutch processing or simply Dutching. Alkalization was invented in the 19th century to get rid of some of the bitterness of cocoa powder and to make it more palatable. Non-alkalized cocoa powder is a more light brown in color and tastes less sweet than alkalized cocoa powder.

Nowadays Dutch processing is very common among industrial chocolate makers (link), which suggests that there's a good chance the average high-sugar milk chocolate will contain alkalized cocoa. Many dark chocolates seem to use non-alkalized cocoa, however, probably because the bitterness is perceived as preferable among chocolate enthusiasts.

4. The cocoa polyphenols in dark chocolate are more bioavailable.

Even if your dark chocolate happens to be made from alkalized cocoa, you'll still get more bang for your buck in terms of polyphenols, because the polyphenols will be more bioavailable. This is again related to differences in the macronutrient composition of chocolates.

First, the bioavailability of cocoa polyphenols depends partly on the fat content of chocolate. One in vitro study showed that cocoa liquor (which is about 50% fat) retained more polyphenols than cocoa powder (about 15% fat) when submitted to a digestion model (link). The reason appears to be that the higher fat content increases the stability of cocoa polyphenols during digestion. Second, sucrose and milk protein may affect the absorption of polyphenols negatively (link).

Dark chocolate contains no milk protein, less sucrose and much more cocoa liquor than milk chocolate. The actual content varies, since different countries have different regulations on what kind of chocolates can be called "dark chocolate". The FDA, for example, states that dark chocolate must contain at least 35% chocolate liquor, while milk chocolate only needs to have more than 10%.

Also, chocolates with 40-70% cocoa are also sometimes sold as "dark chocolate", so be sure to check the ingredient list before purchase. The words "cocoa mass", "cocoa liquor", "cocoa powder", "cocoa paste", "cocoa solids", or something to that effect should be first on the list – if "sugar" is mentioned first, it's definitely not real dark chocolate.

5. Dark chocolate is more filling.

Anyone who has tried both milk chocolate and dark chocolate must have noticed that it takes much less to satisfy chocolate cravings with the latter than the former. I can personally eat 200 grams of milk chocolate (more than 1,000 kcal) in one go without having my craving satisfied. With 99% dark chocolate, a few pieces is enough. A similar effect was shown in a study from last year (link).

This, as mentioned before, is not related to energy content, because milk chocolate and dark chocolate have virtually the same amount of calories. Rather, the reason why a smaller quantity of dark chocolate is enough is probably a combination of less sugar and more nutrients. Humans generally have a preference for sweet foods, which is why we love candy when we're kids. But part of the reason why we can't stop eating candy until we feel sick is that there are no nutrients in candy, only calories. This lack of nutrients causes our body to send the satiety signal way too late.

Since dark chocolate is higher in cocoa powder, it's also higher in many nutrients, such as iron, magnesium, phosphorus, copper and manganese. Combined with the lower amount of sugar and high amount of fat, it's no surprise you get your daily chocolate fix quicker with dark chocolate than milk chocolate.

Summary

Dark chocolate contains less sugar, more cholesterol-neutral fat, and more cocoa polyphenols in a more bioavailable form than milk chocolate. Dark chocolate is also more filling, which means it takes less calories to satisfy your chocolate cravings.

Keep in mind, however, that excess consumption of dark chocolate has its downsides too. Cocoa powder is high in iron and oxalates, which are harmful in high quantities. We'll return to the subject of optimal intakes in future posts, but for now, I limit mine to 50-100 grams of chocolate per day.

For more information on chocolate, sugar, fat, and health, see these posts:

Tea, Coffee and Cocoa: All Good for Your Teeth
SAs, MUFAs vs. PUFAs: Fat Storage Depends on Type of Fatty Acid in Rabbits
Fats and AGEs: PUFAs Are Even Worse than Fructose
Low-Carb vs. Low-Fat: Effects on Weight Loss and Cholesterol in Overweight Men

Read More......


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Monday, October 12, 2009

Which Oils and Fats Are Best for Cooking?

Avocado oil has the highest smoking point.
Avocado oil has the highest smoking point. (Photo by Muffet)

If you've wondered which oils and fats are the best choices for cooking your meals, this post is for you.

The first question we need to ask is what makes an oil good or bad for cooking? Putting the cholesterol issue aside for a moment, we can say that perhaps the most important thing is how well the oil tolerates heat. We are using it for cooking, after all.

Two factors that affect heat tolerance are smoking point and oxidation. Smoking point is, as you might have guessed, the temperature at which the oil begins to smoke. It's also the point the oil starts to break down chemically. This is something you generally want to avoid, so it's usually recommended that you don't heat the oil to its smoking point. This, of course, rules out using oils with a low smoking point for cooking at high temperatures.

The second factor, oxidation, is related to smoking point in the sense that both are affected by temperature. However, oxidation also happens at lower temperatures than are needed for the oil to start smoking. Oxidation is problematic because the lipid peroxidation end-products (ALEs) it creates can wreak havoc inside the body. These products have been shown to accumulate with aging and cause problems such as liver spots on the skin.

So which oils are most susceptible to oxidation? If you've read this blog before then you already know the answer: polyunsaturated fats. In fact, polyunsaturated fatty acids (or PUFAs) tolerate heat very poorly. Not only do they oxidize when you heat them on a frying pan, they do so inside the body as well. On the other hand, monounsaturated fats are much more resistant to oxidation than polyunsaturated fats. Saturated fats are the most resistant.

This gives us a good rule of thumb when looking for fats to use in cooking: avoid oils high in polyunsaturated fatty acids. Because of their potential to undergo lipid peroxidation inside the body, I tend to restrict their consumption altogether, but even if you are a fan of vegetable oils and omega-3, using them for cooking is not a very good idea.


Fatty acid composition of cooking oils
The table above shows the relative percentages of saturated (SA), monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) in various cooking oils and fats (data from US and Finnish food databases). They are in a decreasing order of PUFA content, meaning that the oils moist suitable for cooking are on the left and the least suitable oils are on the right.

As you can see, coconut oil has the highest SA content and the lowest PUFA content of all oils, making it very resistant to oxidation. Ghee and butter also have very little PUFA and lots of saturated fat. Based on this, butter is actually one of the best choices for cooking, although the high AGE content of butter and its tendency to brown quickly suggest to me that perhaps ghee is a better option. The reason might be that butter also contains some protein and a small amount of carbohydrate.

Palm oil and lard are somewhat lower in saturated fat than the first three, but since their MUFA content is quite high, they still make good choices for cooking. The rest to the right of these five are less than optimal. Corn oil, sesame oil, rapeseed oil, peanut oil, and canola oil are all high in polyunsaturates, making them prone to lipid peroxidation. And unless you buy them cold-pressed, they will have been heated during refining anyway, so some oxidation has probably happened before you even use them.

What about olive oil then? Even though everyone seems to love olive oil in general, there's something of a debate going on over whether it should be used for cooking purposes. My opinion is that, like the graph suggests, it's not the worst choice but it's not the best either. The smoking point of extra virgin olive oil seems to vary from 160 to 190 °C, depending on the free fatty acid content. Virgin olive oil, however, has some properties that make it more heat-tolerant than most other oils (link).

In general, the less refined the oil, the lower the smoke point. Unrefined oils high in PUFAs have the lowest smoking points (link), but high saturated fatty acid content does not necessarily guarantee a high smoking point. Coconut oil, for example, has a fairly low smoking point (177 °C, about the same as butter and lard) compared to peanut oil (227 °C). Refined avocado oil, which is mostly monounsaturated fat, appears to have one of the highest smoking points at 255-270 °C (link). Ghee is another oil with a very high smoking point (252 °C).

So which oils should you use for cooking? For sautéing and cooking at light to medium temperatures, my choice would be the ones on the left of the graph: coconut oil, ghee, butter, palm oil, and lard. If you stay below 170 °C, you're in pretty safe waters in terms of oxidation regardless of which one of them you choose. Virgin olive oil seems like a viable choice, too; just make sure the particular olive oil you're using it doesn't start smoking.

For searing, browning and other methods of cooking requiring higher temperatures, ghee and avocado oil seem like the best choices. When it comes to resistance to oxidation, ghee might take the cake, but avocado oil appears to have the highest smoking point of all oils, even though it does have 13.5% PUFAs. Still, keep in mind that when cooking at very high temperatures, some advanced glycation end-products (AGEs) are bound to be generated.

For more information on fats and health, see these posts:

Coconut Lowers LDL, VLDL and Triglycerides, Raises HDL
My Current Health Regimen
Blood Test Analysis: The Cholesterol and Saturated Fat Issue Revisited
Should Saturated Fat Be Avoided in Low-Carb Diets?

Read More......


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Wednesday, October 7, 2009

Fats and AGEs: PUFAs Are Even Worse than Fructose

Olive oil is mostly monounsaturated fat.
Olive oil is mostly monounsaturated fat. (Photo by Splat Worldwide)

While the exact role AGEs play in aging is still unclear, it seems that reducing their accumulation in the body is a useful goal. And if for no other reason, how about being superficial: liver spots, for example, are a visible sign of AGEs in the skin. If you want to look youthful, glycation is not the way to go.

The question of how to avoid AGEs has proven to be more difficult than one might think, however. If it was merely a matter of reducing the formation of advanced glycation end-products during cooking, we could just cook our foods at lower heat and use water instead of frying at high temperatures. But as we've seen, the AGEs we get directly from food may not be as important as the AGEs that form inside our body as a result of internal glycation.

The term 'advanced glycation end-product' is somewhat misleading in the sense that they are not formed only by glycation, which refers to glucose molecules binding to protein or lipid molecules, but also by fructation, which is essentially the same thing but this time with fructose. In fact, fructose is much more prone to form these products than glucose. Since there's no such term as 'advanced fructation end-product', they're also referred to as AGEs (other sugars like galactose go through a similar process too; more on that in another post).

To complicate this further, similar products are also formed during cooking when fats alone are exposed to high heat and air. This process is known as lipid peroxidation. The end results of lipid peroxidation are referred to as either AGEs or ALEs, short for advanced lipoxidation end-products. For the sake of simplicity, I will refer to all of them as AGEs, unless the difference is important.

So we now have several different ways to accumulate AGEs: eating cooked foods that contain sugars heated with protein or fats, eating uncooked foods that contain sugars, or eating oxidized fats. And, like glycation, lipid peroxidation can also happen endogenously. That is, even if the fats you eat do not contain any AGEs, they can still form AGEs inside the body if they are unstable and prone to oxidation.

The bad news is that not only does lipid peroxidation lead to AGEs, it appears to do so more rapidly than glycation does. CML, a product of the oxidative degradation of glycated protein and a common measure of AGE levels, is actually formed through the oxidation of arachidonic acid in much higher quantities than from glycation (link). CML is a handy way to compare things, because it can be formed through glycation, fructation or lipid peroxidation.

The reason you should keep your fish oil and flax seed oil in the fridge is precisely because they, like other highly unsaturated fats, are easily oxidized (link). Cooking with these oils is a really bad idea. Through lipid peroxidation, polyunsaturated fats or PUFAs are more prone to form AGEs. Below is a comparison of CML formation from three different fatty acids and glucose (link):


AGE formation from glucose and lipids
The left graph shows that arachidonic acid forms CML at about twice the rate as linoleic acid. The formation of CML from oleic acid is close to zero. Compared to glucose in the right graph, the two PUFAs here are at least 10 times as prone to AGE formation – very much like fructose, except that if you look at the fructose graphs, the 10-fold increase is not seen as early as it is in these graphs.

The explanation for the differences is that lipid peroxidation increases exponentially as a function of the number of double bonds (link), i.e. the degree of unsaturation. Arachidonic acid is a 20-carbon chain PUFA with four double bonds and linoleic acid is an 18-carbon chain PUFA with two double bonds. Oleic acid, like all MUFAs, has one double bond. Note that this equation makes the omega-3 fatty acids DHA and EPA (with their 6 and 5 double bonds, respectively) the worst offenders.

So oils high in PUFAs seem to have the ability to raise the AGE burden much more than glucose, or even fructose. This could potentially explain some of the differences in AGE levels between omnivores and vegetarians – maybe vegetarians eat more vegetable oils than omnivores, since glucose and fructose intakes alone are insufficient to explain the results. The authors of the paper state:

Oxidation of fatty acid is clearly a more efficient source of CML, despite the fact that the glucose is in solution throughout the course of the experiment, while the PUFA are only progressively solubilized. Further, after 6 days of incubation, a large fraction of the arachidonate was oxidized based on its solubilization in the aqueous phase, while less than 2% of the glucose is oxidized during this same time period.

In the same study, arachidonic acid produced more than 10 times the amount glyoxal than it did CML. Glyoxal is another inflammatory compound, which in food is created by heating unstable (i.e. polyunsaturated) oils to high temperatures but which, again, can also be formed inside the body. Some of this glyoxal goes on to form AGEs, but the rest that doesn't isn't exactly life elixir either.

Unfortunately, the problems don't end with CML. Polyunsaturated fats also quite easily form other AGEs, such as malondialdehydelysine (MDA-lys) and carboxyethyllysine (CEL). Indeed, rats fed a diet high in PUFAs have over twice the level of MDA-lys in their brains compared to rats fed a diet high insaturated fat diet (link). Their levels of CEL and CML in the brain and MDA-lys in the liver are also significantly higher (although CEL and CML are lower in the liver). Unsurprisingly, MDA and CML deposits in the brain are implicated in Alzheimer's disease (link).

As I mentioned before, simply avoiding cooking with oils rich in PUFAs is probably not enough, because exposing them to high heat and air in the frying pan isn't the only thing that causes them to form AGEs. Reactive species such as radicals, transition metals, other electrophiles, and enzymes can also cause their oxidation inside the body (link).

In fact, it's not certain based on the studies mentioned here just how bad food-derived ALEs are. Perhaps ALEs from food are less important than ALEs formed endogenously. Endogenous AGEs certainly appear to play a bigger role than exogenous AGEs, although consuming excess amounts of AGEs is probably not a good idea either.

Personally, I'm trying to limit both endogenous and exogenous AGEs and ALEs by avoiding cooking at high temperatures and using saturated fats for frying. Stay tuned for more posts on the issue. Meanwhile, see these posts on glycation and fats:

AGE Content of Foods
The 7 Types of Aging Damage That End up Killing You
Green Tea Reduces the Formation of AGEs
Should Saturated Fat Be Avoided in Low-Carb Diets?

Read More......


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