Tag Archives: Dietary supplement

Can methylene blue improve memory?

1 Jul

Methylene blue is a chemical that has been used an antidote for cyanide poisoning. There have been suggestions over the years that it may have an effect on  memory. A paper titled “Multimodal Randomized Functional MR Imaging of the Effects of Methylene Blue in the Human Brain,” was recently published in the journal Radiology. Unfortunately, I have not been able to locate a copy of the original paper, so I am forced to rely on this account in ScienceDaily:

“A single oral dose of methylene blue results in an increased MRI-based response in brain areas that control short-term memory and attention, according to a new study. Methylene blue was associated with a 7 percent increase in correct responses during memory retrieval.”

Several media outlets report that methylene blue was shown to improve short term memory. This is one of the reasons I need to see the original paper. The phrase “short term memory” is used differently by psychologists than the general public. Indeed, many psychologists have abandoned the phrase altogether and, instead, talk about working-memory. When non-academics talk about short term memory they mean things like forgetting a phone number or someone’s name. In fact, most of these are failures of attention or long term memory, not problems with short term memory. Thus, I worry that reporting on this research may be very misleading.

The false promise of fish oil

24 Jul

I have been blogging a lot about diet lately and I should move onto other topics, but I think this Washington Post story is important:

“People in the United States spend about $1.2 billion annually for fish oil pills and related supplements even though the vast majority of research published recently in major journals provides no evidence of a health benefit.”



Can nutritional supplements improve cognition in the elderly?

22 Jun

A review, just published, in Current Directions in Psychological Science:

“With increasing life expectancies in most Western populations, the number of people experiencing age-associated cognitive impairment is increasing. Research is needed to identify factors that may help the elderly maintain or even improve cognitive function in the face of advancing age. This review evaluates whether dietary supplementation with natural pharmaceuticals can be used as a means to improve cognitive function or limit cognitive decline. The evidence surrounding popular supplements such as Ginkgo biloba, fish oils, Bacopa monnieri, polyphenol extracts, and vitamins is reviewed briefly. Potential mechanisms of action are also highlighted. This review also discusses challenges surrounding cognitive testing in psychopharmacological research, highlighting discrepancies between the domains of human cognition as described by contemporary models and as measured in clinical trials.”

Here is the paper’s concluding paragraph:

“The results of the clinical trials reviewed here are an admixture of hopeful findings, often leavened by studies of small duration and sample size. Although difficult and costly to conduct, trials of longer duration are needed to ascertain which dietary supplements, if any, afford protection against cognitive decline and cognitive impairment. Differences between existing studies also make it hard to draw overall conclusions about any particular supplement. In our own work, standardized herbal extracts of bacopa and pine bark have shown promise in terms of their ability to improve cognitive function, with a larger trial of longer duration currently underway to validate these preliminary findings (Stough et al., 2012). Meta-analyses have shown that multivitamins, fish oils, and ginkgo can all enhance specific aspects of cognitive function. To minimize differences in cognitive outcomes between studies, we suggest cooperation between different groups working in the area to develop a set of freely available cognitive tasks validated against the CHC model.”

This is paper, published in a highly regarded journal, is very optimistic about the prospect of nutritional supplementation. I am open minded about this, but note that research in this area tends to follow cycle: initial poorly designed studies raises hopes, while the effect tends to disappear with later better designed studies. I am particularly skeptical about claims made about fish oil.

Krill oil shortens mouse life span

2 Sep

Beware of the claims made on behalf of the various fish oil products. Here is a recent study suggesting that krill oil (a popular fish oil supplement) shortens the life span of mice. From the abstract:

“Taken together, the results do not support the idea that the consumption of isolated ω-3 fatty acid-rich oils will increase the life span or health of initially healthy individuals.”


Memory supplement take down

11 Jun

The Federal Trade Commission and Martek Biosciences Corporation have reached a settlement over the companies deceptive claims for a memory supplement. The supplement was named Brainstrong and contained DHA and green tea extract.

Memory myths #2: Ginkgo biloba?

24 Jun

Can we improve memory by just taking a pill?

Claims for supplements like ginkgo often follow a predictable story arc: initial claims are made based on small poorly controlled studies or population correlations. Supplement companies heavily promote these products, but when rigorous experimental trials are finally conducted no evidence of effectiveness is found. One should always keep an open mind and I have tried my share of these supplements. Unfortunately, our best evidence, suggests that Ginkgo biloba does not enhance memory and I no longer take it. In fact, there is some evidence that Ginkgo may be toxic.

This does not prelude the possibility that supplements or dietary manipulation might improve memory, but we should pay more attention to rigorous scientific research than advertising hype.

One piece of scientifically sound dietary advice: a balanced plant based diet will reduce your risk of dementia.

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