We all have days when we feel “sharp” and others where everything seems a bit foggy. As we age, those foggy periods may feel more frequent. Small changes in cognition are common with aging, but many see this as sign of impending cognitive decline and even dementia. And dementia is an unfortunate reality for millions – Alzheimer Disease alone affects 6 million Americans. With no really effective prescription medications for the treatment or prevention of cognitive decline, many consumers turn to vitamins and dietary supplements. I recently spotted advertisements for a product called “Clear Brain” which is marketed to “enhance cognitive function and memory in adults”. This isn’t the only product marketed for cognition – there are many products with a huge array of ingredients. Is there evidence to suggest that you can reduce the risk of cognitive decline with dietary supplements?
A product marketed to enhance cognitive function should be backed by clinical trials, because it’s not practically possible for an individual to objectively assess any benefits themselves. Clear Brain contains a variety of ingredients which I’ll go through in order to evaluate the evidence.
Pomegranate fruit extract (75 mg) – Pomegranate is usually eaten raw or consumed as juice. The juice may have a minor effect on blood pressure. There is no published information to demonstrate that fruit extract has any meaningful effects on cognition. However, it’s considered safe to consume.
Green tea leaf extract (75 mg) – Green tea is widely consumed. Heralded for cardiovascular health (where regular tea drinking may be beneficial), there is little evidence to demonstrate it has a role in cognition. There are some trials including one with matcha green powder, where 3 grams a day for 12 weeks had no benefit over placebo. Another trial on cognitive function in adults, also placebo-controlled, did not improve most measures of cognition.
Ginkgo leaf extract (60 mg) – Ginkgo has a long history of use in Chinese medicine. Interestingly, the ginkgo tree is the world’s oldest living tree species. Ginkgo is currently widely used, and the extract is considered safe and well tolerated. Ginkgo is believed to improve blood flow to the brain, and is claimed to treat memory loss and dementia. Clinical trials with ginkgo for the treatment of dementia are numerous and the results are mixed, with no consistent effect shown. Trials for prevention do not show a clear benefit.
French maritime pine bark extract (40mg) – This ingredient is commercially sold as a single ingredient in the supplement Pycnogenol. (Examine.com has a good summary of the trials and their limitations.) There are trials with that product that have examined cognition and reported positive effects on some measures. It isn’t known if trials with Pycnogenol are relevant to this or other supplements, as the method of preparation and actual chemical constituents may differ.
Walnut seed extract (25mg) – A search for evidence on this product finds that it is mainly used as a cosmetic. English walnuts are a tree nut which are a popular food. All the studies I could find were of whole nut consumption, mainly for cardiovascular conditions. I could find no trials with the extract and no trials examining effects on cognition.
Black pepper fruit extract (3mg) – This appears to be the same type of pepper you’re putting on your food. There is no evidence that this tiny amount has any effects on cognition, though there is research suggesting it may be helpful in mice models of dementia. Black pepper is claimed to promote the absorption of other chemicals, so that could also be the reason for inclusion in supplements.
Vitamins (Folate, Pantothenic acid, thiamine, niacin, riboflavin, B6, B12, etc.) – There is no evidence that vitamin supplements can improve cognition or reduce the risk of cognitive decline. The best way to obtain vitamins is via the diet, and supplementation is only suggested where dietary intake is low. Importantly, a nutrient-rich diet like the Mediterranean diet or the DASH diet is actually associated with a reduction in the risk of cognitive decline.
Does anything work to protect the brain from cognitive decline?
The World Health Organization has produced a detailed document on how to reduce the risk of dementia. Recommendations (with varying levels of evidence) include physical activity, tobacco cessation, Mediterranean-like diets, weight management, reducing alcohol consumption, managing hypertension, and preventing or treating diabetes. They noted no effects (and make no recommendations in favor of) multi-supplement complexes, vitamins B and E, and polyunsaturated fatty acids.
Strategies to support your cognition
No dietary supplements, either alone or in combination, have been proven to demonstrate any meaningful benefit to prevent or treat cognitive decline. There is no scientific justification for the sale of these supplements as the marketing claims are unsupported. Those interested in maintaining cognitive function as they age should strive to lead a healthy lifestyle that includes a balanced diet, regular exercise, managing health conditions like diabetes or hypertension, and moderating or minimizing alcohol consumption.