Diet supplements

Food & Supplements

There is little evidence that dietary supplements or changes to the diet improve mental function in young, healthy people.

Changes in diet and dietary supplements may be beneficial to older adults, or those suffering from physical disorders, allergies, depression, stress, etc.

Despite the claims made for many supplements, we can't point unequivocally to any as beneficial. Whether they are of benefit does depend on whether you are lacking in some vitamin and mineral (e.g., Vitamin B12), so it is advisable to have your levels checked.

Food is safer, and the evidence does now seem clear that fruit and vegetables rich in anti-oxidants are of particular benefit.

A perennial topic in the arena of memory improvement is the question of “food for the brain”, and in particular, whether there are dietary supplements that can improve your mental abilities. While my own emphasis is improvement through development and practice of skills, I don’t dismiss the possibility of improvement through more physical means. I myself am a great fan of the “you are what you eat” principle. This is mainly because I suffer from multiple food sensitivities, so the consequences of food are very much a reality for me. That doesn’t mean I believe perfectly healthy people should obsess about their diet. There is another principle that is of great importance: we are all individuals.

For example, a year ago, I wrote of the effects of caffeine on memory, concluding that: “while caffeine may help older adults in the later part of the day, those with hypertension, diabetes, impaired glucose tolerance, or high homocysteine levels, would be wiser to avoid coffee, even if decaffeinated. In general, while caffeine may help you overcome factors that lower your cognitive performance, it does not seem that caffeine has any significant direct effect on memory, although it may well help you pay attention.”

So, caffeine is more helpful for some types of people than others, and is in fact contra-indicated for some. Moreover, the effects are different for those who are accustomed to a high caffeine intake, compared to those who only occasionally consume caffeine. And – here’s the real kicker – I also know from personal experience that the effects of caffeine are highly individual: I myself respond to caffeine not with the usual increased alertness, but in fact with decreased alertness. It makes me sleepy!

I do think there are physical factors of far greater importance than diet. Sleep is the obvious one. Individual differences don’t show up in the basic need to have enough sleep, and the right sort of sleep, to optimize brain functioning, but they do of course show up as regards how much sleep is right for us. That also, is something that changes with age, and, I imagine, health, throughout our lifespan.

Another physical factor which should be given due weight is exercise. While its effect is not as great as sleep (I don’t think anything rivals the importance of sleep!), I would give it more importance than diet because its effect is far more consistent. I don’t think anyone would fail to benefit mentally from increased physical fitness (which is not to say there isn’t a level of fitness beyond which no more mental improvement will occur).

Diet, on the other hand, depends a great deal on the individual. There is little evidence that dietary supplements or changes to the diet improve mental function in those who don’t suffer from any of the conditions which can adversely affect brain function — e.g., aging, physical disorders, depression, stress, etc.

In other words, if you are a relatively young person with no health problems, I suggest you concentrate on getting enough sleep and exercise, and learning and practicing effective memory strategies.

If you have any conditions which can adversely affect brain function I would also emphasize doing this! But, additionally, I do think there are foods and supplements you can take which may well significantly improve your brain function.

Which ones? Here we enter the area of individual difference. To find out what is effective for you, you should start with the research. What foods and supplements have been demonstrated to be effective in improving cognition?

Here we enter an area fraught with difficulty. News reports come out about foods and supplements all the time, and today’s world is filled with people hawking “health” products. How do we know what to believe?

The first thing, of course, is to ascertain whether the claims are backed up by research. But that’s not as easy as it sounds, because every seller of such products knows the importance of sounding as if research has proven the effectiveness of their product. (Actually, I automatically disavow any text which talks of research “proving” something. No researcher worth his salt would ever make such a claim.)

How do we determine the genuineness and reliability of the research? First, and most importantly, by assessing the source. For example, I only cite research from reputable academic journals, or academic conferences. I also give greater weight to research from researchers whose work I know of. Hopefully, by so doing, I also make myself a reliable source.

This is not, however, infallible, for even well-respected journals can make mistakes. For example, very topically, the truthfulness of a widely reported study of a nutritional supplement's effects on thinking and memory in the elderly has recently been cast into doubt (actually, this is a rather polite phrase for the comments now being made: “scientists who reviewed the paper had found the methods and statistical findings so unlikely that they wondered whether the study had actually been done”; "The statistics were not just implausible, they were impossible.")

Nevertheless, the very shock with which these questions are being raised demonstrates that, by and large, the system does work. We cannot expect certainty.

Having approved the source, the second thing to consider is the extent to which the research has been replicated. One study does not make an answer! It is indicative only. It is interesting.

Even a second study is little more than another support. Before we can say, “You know, I really think there’s something to this”, we need a number of studies building together from different angles.

So, a study showing that sage can help cognitive function in healthy young adults (there is indeed such a study) is interesting. Given that sage is easy to grow, and commonly consumed (one doesn’t need to worry about toxicity), I would go so far as to say, give it a try! But I wouldn’t give a lot of weight to the research until more studies had been carried out. (I would, however, happily drink sage tea everyday on the off chance, except it turns out – I really can’t believe this! – I’m sensitive to sage, too.)

On the other hand, for a product that is expensive, or has potential side-effects, I would wait for more evidence to come in before trying it. Okay, we’ve looked at the research, we’ve found the foods and supplements of potential benefit. What next?

Next, you look at your own particular problems.

For example, my main problem is food sensitivities. The first, most dramatic, thing I did to overcome my increasing mental sluggishness was: stop eating foods which turned out to be bad for me! After concentrating on that for a year or two, with my physical and mental problems much improved (but not gone), I turned my attention to the damage done to my body over the long period during which I was unaware of my food sensitivities. I now take B12, which I am sure has had a significant effect on my brain, and have recently started taking iron (as a woman of childbearing age). I also take other mineral supplements, principally to overcome deficiencies in my environment (New Zealand’s soil is deficient in a number of minerals), and lecithin (partly because of the deficiencies in my diet as a result of having to avoid certain foods).

The final step, once you’ve established the possible foods and supplements which are worth trying, is to see whether they are effective for you. Remember me and the coffee. What works for one doesn’t necessarily work for another (and may indeed be harmful). But don’t try everything at once! One at a time, and the most likely first.

So, what foods and supplements might be of benefit to your brain?

Most of the research into the cognitive benefits of diet and supplements has been concerned with seniors, with alleviating the effects of age on the brain. This is consistent with the belief that there is little, if any, benefit to be gained by young, healthy adults. Having said that, however, the following have been shown to be of benefit in at least one study:

  • creatine
  • sage
  • lemon balm
  • a diet high in soy products

Remember my comment about the reliability of single studies! However, since three of these four are all perfectly “natural” food items, there would be little danger in trying these out.

Several substances are worth mentioning as having been of particular interest to researchers for their potential benefits to brains suffering from the effects of age:

  • gingko biloba
  • ginseng
  • choline (lecithin)
  • vitamin B12
  • phosphatidylserine (PS)
  • acetyl-L-carnitine (ALC)
  • antioxidants (particularly vitamin E)

This article originally appeared in the May 2004 newsletter.

Gingko Biloba

The most convincing study has found no benefit of gingko biloba on cognition in older adults.

Previous evidence that gingko biloba can improve memory has been decidedly mixed.

The most promising results have occurred with multiple sclerosis patients; there is also some reason to think those with cardiovascular problems may benefit.

Gingko biloba is not without side-effects.

The quality of the supplements is also probably a factor in determining whether it will be of value.

Most studies supporting the use of gingko have been looking at its use in people suffering from dementia, Alzheimer's, multiple sclerosis etc. That is, not in healthy seniors. There is some evidence that gingko may be helpful with cardiovascular problems and, given recent research that suggests "what's good for the heart is good for the brain", perhaps this is the source of any effects gingko may have on memory and cognitive function.

Gingko can have serious side-effects - those taking other medications, or about to undergo surgery, are advised to tell their doctor if they are taking gingko. There is also some evidence that it may be a danger to unborn children. Nor is it yet clear what the correct dose might be (one study found a beneficial effect at a low dose, but no effect when a higher dose was used!) The quality of the various gingko preparations for sale is also quite variable.

Given these caveats however, some individuals may find gingko helpful - chiefly, it would appear, in terms of a slightly increased alertness. I would speculate that those who do find it helpful are those people whose memory problems are caused by certain cardiovascular risk factors, such as high cholesterol.

I would remind you that my background is in cognitive psychology, I am not a medical doctor. This is my understanding of the situation from the various reports I have read.

This article originally appeared in the September 2002 newsletter.

Nutrient cocktail for early Alzheimer's passes second trial

A second controlled trial of the nutrient cocktail Souvenaid has confirmed its cognitive benefits for those in the early stages of Alzheimer’s.

Two years ago, I reported on a clinical trial of a nutrient cocktail called Souvenaid for those with early Alzheimer’s. The three-month trial, involving 225 patients, had some success in improving verbal recall, with those with the mildest level of impairment benefiting the most.

The ‘cocktail’, designed by a MIT professor of brain and cognitive science, includes choline, uridine and the omega-3 fatty acid DHA. Earlier research indicated that these nutrients — precursors to the lipid molecules that help make up neural membranes — need to be administered together to be effective. In animal studies, the cocktail increased the number of dendritic spines, which are reduced in Alzheimer’s disease.

A further trial of the supplement has now been reported on. This randomized, controlled double-blind study followed 259 patients with early Alzheimer’s for six months. The placebo group was given an iso-caloric control product. Compliance was high (around 97%), and no serious side effects occurred.

During the first three months, all patients improved their verbal memory performance, but after that those on placebo began to deteriorate, while those on Souvenaid continued to improve. Their performance at the end of the trial was significantly better than that of the placebo group. Moreover, brain scans showed that their brains began to show more normal activity patterns, consistent with the regaining of greater synaptic function.

Because the supplement only seems to be effective for those in the early stages (in this study, participants averaged around 25 on a scale of dementia that ranges from 1 to 30, with 30 being normal), a two-year trial is now underway with patients with MCI.

Reference: 

Scheltens, P. et al. 2012. Efficacy of Souvenaid in Mild Alzheimer’s Disease: Results from a Randomized, Controlled Trial. Journal of Alzheimer’s Disease, 31 (1), 225-36.

Pycnogenol improves cognition in college students in small trial

Another small study indicates that the plant extract Pycnogenol may improve working memory.

Back in 2008, I reported on a small study that found that daily doses of Pycnogenol® for three months improved working memory in older adults, and noted research indicating that the extract from the bark of the French maritime pine tree had reduced symptoms in children with ADHD. Now another study, involving 53 Italian university students, has found that cognitive performance improved in those taking 100 mg of Pycnogenol every day for eight weeks.

Students taking the supplement had higher scores on university exams than the control group, and they were apparently happier, less anxious, and more alert. It seems plausible that the improvement in academic performance results from working memory benefits.

The plant extract is an antioxidant, and benefits may have something to do with improved vascular function and blood flow in the brain.

However, the control group was apparently not given a placebo (I’m relying on the abstract and press release here, as this journal is not one to which I have access), they were simply “a group of equivalent students”. I cannot fathom why a double-blind, placebo procedure wasn’t followed, and it greatly lessens the conclusions of this study. Indeed, I wouldn’t ordinarily report on it, except that I have previously reported on this dietary supplement, and I am in hopes that a better study will come along. In the meantime, this is another small step, to which I wouldn’t give undue weight.

Reference: 

Luzzi R., Belcaro G., Zulli C., Cesarone M. R., Cornelli U., Dugall M., Hosoi M., Feragalli B. 2011. Pycnogenol® supplementation improves cognitive function, attention and mental performance in students. Panminerva Medica, 53(3 Suppl 1), 75-82.

Dietary supplements - news topics

Read the topic summary (forthcoming)

Older news items (pre-2010) brought over from the old website

Evidence mounts against DHEA use in treating cognitive decline

DHEA is a naturally-occurring hormone in the human body that declines with age. Previous research looking at the effect of DHEA supplementation on cognitive function and quality-of-life has produced inconsistent results. In the first long-term study (12 months) of healthy older adults, 110 men and 115 women aged 55-85 received either daily 50 mg doses of DHEA or a similar looking placebo pill for 1 year. It was found that, although youthful levels of DHEA were restored in the treatment group, the supplements had no benefits for cognitive function or quality-of-life in this representative sample.

[1222] Kritz-Silverstein, D., von Mühlen D., Laughlin G. A., & Bettencourt R. (2008).  Effects of Dehydroepiandrosterone Supplementation on Cognitive Function and Quality of Life: The DHEA and Well-Ness (DAWN) Trial. Journal of the American Geriatrics Society. 56(7), 1292 - 1298.

http://www.eurekalert.org/pub_releases/2008-05/w-ema052108.php

French maritime pine bark improves memory in elderly

A double-blind, placebo controlled, matched pairs study examined the effects of Pycnogenol (an antioxidant plant extract from the bark of the French maritime pine tree) on a range of cognitive and biochemical measures in 101 senior individuals aged 60-85 years old. Participants had a daily dose of 150mg for three months. Pycnogenol improved both numerical working memory as well as spatial working memory. Blood samples revealed that F2-isoprostanes significantly decreased with Pycnogenol, a sign of reduced oxidation of nerve membranes, suggesting that the antioxidant activity of Pycnogenol plays a major role for the clinical effects. Several recent research studies have found Pycnogenol reduced ADHD symptoms such as hyperactivity and improved attention, concentration and motor-visual coordination in children with ADHD. Pycnogenol extract has been studied for 35 years and is available in more than 600 dietary supplements.

[2425] Ryan, J., Croft K., Mori T., Wesnes K., Spong J., Downey L., et al. (2008).  An examination of the effects of the antioxidant Pycnogenol(R) on cognitive performance, serum lipid profile, endocrinological and oxidative stress biomarkers in an elderly population. J Psychopharmacol. 22(5), 553 - 562.

http://www.eurekalert.org/pub_releases/2008-03/mg-nsp031708.php

Long-term beta carotene supplementation may help prevent cognitive decline

A large, long-running study has found that men who took beta carotene supplements for 15 years or longer had significantly higher scores on several cognitive tests compared with men who took placebo. There was no such effect in those men who took the supplements for a year. The researchers suggest that although the benefits were modest in themselves, they may predict substantial differences in eventual risk of dementia. However, it should be noted that beta carotene is not without risks—for example, it may increase the risk of lung cancer in smokers — and that it would be premature to advise use of such supplements.

[710] Grodstein, F., Kang J. H., Glynn R. J., Cook N. R., & Gaziano M. J. (2007).  A Randomized Trial of Beta Carotene Supplementation and Cognitive Function in Men: The Physicians' Health Study II. Arch Intern Med. 167(20), 2184 - 2190.

http://www.eurekalert.org/pub_releases/2007-11/jaaj-lbc110807.php

Dietary supplements improve old rats' memory and energy levels

After only a month, older rats fed two chemicals normally found in the body's cells and available as dietary supplements — acetyl-L-carnitine and an antioxidant, alpha-lipoic acid — performed better on memory tests, and had noticeably more energy (on a par with a “middle-aged” rat). It is thought that these chemicals act on the mitochondria, the “power-houses” of the cells. Mitochondria are increasingly being implicated as especially vulnerable to the aging process. Carnitine is a natural compound produced in the cell and obtained in the diet through meats and vegetables. It has been shown to improve balance and short-term memory in human. Lipoic acid is found in green, leafy vegetables.
The University of California has patented use of the combination of the two supplements to rejuvenate cells. Human clinical trials are currently underway.

[1215] Hagen, T. M., Liu J., Lykkesfeldt J., Wehr C. M., Ingersoll R. T., Vinarsky V., et al. (2002).  Feeding acetyl-l-carnitine and lipoic acid to old rats significantly improves metabolic function while decreasing oxidative stress. Proceedings of the National Academy of Sciences of the United States of America. 99(4), 1870 - 1875.

[618] Liu, J., Head E., Gharib A. M., Yuan W., Ingersoll R. T., Hagen T. M., et al. (2002).  Memory loss in old rats is associated with brain mitochondrial decay and RNA/DNA oxidation: Partial reversal by feeding acetyl-l-carnitine and/or R-α-lipoic acid. Proceedings of the National Academy of Sciences of the United States of America. 99(4), 2356 - 2361.

[1232] Liu, J., Killilea D. W., & Ames B. N. (2002).  Age-associated mitochondrial oxidative decay: Improvement of carnitine acetyltransferase substrate-binding affinity and activity in brain by feeding old rats acetyl-l- carnitine and/or R-α-lipoic acid. Proceedings of the National Academy of Sciences of the United States of America. 99(4), 1876 - 1881.

http://www.eurekalert.org/pub_releases/2002-02/uoc--dsm021502.php
http://www.eurekalert.org/pub_releases/2002-02/osu-crr021902.htm

DHA improves memory in older adults with cognitive impairment

A largish clinical study of cognitively impaired older adults has found six months of DHA supplements improved visual and verbal learning, though not working memory.

There have been mixed findings about the benefits of DHA (an omega-3 fatty acid), but in a study involving 485 older adults (55+) with age-related cognitive impairment, those randomly assigned to take DHA for six months improved the score on a visuospatial learning and episodic memory test. Higher levels of DHA in the blood correlated with better scores on the paired associate learning task. DHA supplementation was also associated with better verbal recognition, but not better working memory or executive function.

Other research has found no benefit from DHA to those already with Alzheimer’s, although those with Alzheimer’s tend to have lower levels of DHA in the blood. These findings reinforce the idea that the benefit of many proactive lifestyle strategies, such as diet and exercise, may depend mainly on their use before systems deteriorate.

The daily dose of algal DHA was 900 mg. The study took place at 19 clinical sites in the U.S., and those involved had an MMSE score greater than 26.

Vitamin B supplements could delay onset of Alzheimer's

Vitamin B supplements markedly reduced brain atrophy in older adults with MCI, offering hope that they may be effective in delaying the development of Alzheimer’s.

A two-year study involving 271 older adults (70+) with mild cognitive impairment has found that the rate of brain atrophy in those taking folic acid (0.8 mg/d), vitamin B12 (0.5 mg/d) and vitamin B6 (20 mg/d), was significantly slower than in those taking a placebo, with those taking the supplements experiencing on average 30% less brain atrophy. Higher rates of atrophy were associated with lower cognitive performance. Moreover those who with the highest levels of homocysteine at the beginning of the trial benefited the most, with 50% less brain shrinkage. High levels of homocysteine are a risk factor for Alzheimer’s, and folate, B12 and B6 help regulate it.

The finding that atrophy can be slowed in those with MCI offers hope that the treatment could delay the development of Alzheimer’s, since MCI is a major risk factor for Alzheimer’s, and faster brain atrophy is typical of those who go on to develop Alzheimer’s.

Nutritional drink may help fight Alzheimer's

A clinical trial has found improvement in verbal (but not general) memory in patients with mild Alzheimer's who drank a nutritional cocktail for 12 weeks.

A European trial involving 225 patients with mild Alzheimer's has found that those who drank Souvenaid (a cocktail of uridine, choline and the omega-3 fatty acid DHA, plus B vitamins, phosopholipids and antioxidants) for 12 weeks were more likely to improve their performance in a delayed verbal recall task. 40% of the Souvenaid group showed improved performance compared to 24% of the placebo group. Those with the mildest cases of Alzheimer’s showed the most improvement. There was no improvement on the more general ADAS-cog test. Three further clinical trials, one in the U.S. and two in Europe, are now underway.

Reference: 

Scheltens, P. et al. 2010. Efficacy of a medical food in mild Alzheimer's disease: A randomized, controlled trial. Alzheimer's & Dementia, 6 (1), 1-10.

Vital role in brain development for the nutrient choline

The nutrient choline is known to play a critical role in memory and brain function by positively affecting the brain's physical development through increased production of stem cells (the parents of brain cells). New research demonstrates that this occurs through the effect of choline on the expression of particular genes. The important finding is that diet during pregnancy turns on or turns off division of stem cells that form the memory areas of the brain. Developing babies get choline from their mothers during pregnancy and from breast milk after they are born. Other foods rich in choline include eggs, meat, peanuts and dietary supplements. Breast milk contains much more of this nutrient than many infant formulas. Choline is a vitamin-like substance that is sometimes treated like B vitamins and folic acid in dietary recommendations.
A choline food database is available at: www.nal.usda.gov/fnic/foodcomp.

Dietary supplements offer new hope for Alzheimer's patients

A "cocktail" of dietary supplements (omega-3 fatty acids, uridine and choline) has been found to dramatically increase the amount of membranes that form brain cell synapses in gerbils. The treatment is now in human clinical trials. It is hoped that such treatment may significantly delay Alzheimer's disease. The treatment offers a different approach from the traditional tactic of targeting amyloid plaques and tangles. Choline can be found in meats, nuts and eggs, and omega-3 fatty acids are found in a variety of sources, including fish, eggs, flaxseed and meat from grass-fed animals. Uridine, which is found in RNA and produced by the liver and kidney, is not obtained from the diet, although it is found in human breast milk.

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