Nutrition, natural products and supplements
Diet can have a major impact on the health of your brain. Supplements, traditional herbs, nutraceuticals and other natural products can also affect your health. Could they protect your brain? Are they safe? Here, we rate the scientific evidence and give you the info.
* See the Evidence guide for color legend and more information.
Fish and long-chain omega-3 fatty acids, DHA & EPA
DHA and other long-chain omega-3 polyunsaturated fatty acids are found in fatty fish and fish oil. Supplementation does not improve cognition in most elderly people but could benefit people with cognitive impairment that is less severe than dementia. Although the evidence has surprising discrepancies, people who have more of these fatty acids in their blood appear less likely to develop Alzheimer’s.
Cinnamon might theoretically protect against Alzheimer’s but the evidence is based solely on animal and test-tube studies that have not been verified in humans. In at least one clinical trial, cinnamon did not elicit anti-aging benefits suggested from laboratory research. A handful of small clinical trials suggest that cinnamon might improve metabolism in diabetic patients. Cinnamon is safe for general consumption but allergic reactions can occur and high doses can carry risks.
Used for centuries as a medicinal herb, bacopa may slightly improve scores on some cognitive tests in some people. Scientists are exploring other claims that it can protect against a variety of diseases but the evidence so far is very minimal.
Huperzine A might modestly improve memory and global cognition in patients with vascular dementia and Alzheimer’s disease; however, many caveats prevent clear conclusions. Huperzine A appears safe for short-term use but evidence for long-term safety is lacking.
No evidence suggests berberine can promote brain health in humans or treat cognitive decline or dementia. Berberine might help to manage diabetes, high cholesterol and high blood pressure for some people. Although it may be safe for short term use, berberine interacts dangerously with some medications and evidence for long-term safety is lacking.
Astragalus is a large group of herb species used in traditional Chinese medicine. Currently there is very limited evidence from human research suggesting neuroprotective benefits and improved learning and memory effects, and limited evidence for reduced age-related disease. Astragalus appears safe for short-term use but evidence for long-term use safety is lacking.
TA-65 is a commercially available nutraceutical that may activate the enzyme telomerase. Very little evidence exists to suggest any health benefits. TA-65 appears safe for short-term use but evidence for long-term safety is lacking.
Lithium: Dietary and Supplement Doses
Lithium is a mineral naturally found throughout the body. Lithium at dietary or supplement doses between 0.3 to 5 mg per day could theoretically protect the brain but the evidence is limited to one pilot clinical trial. Although higher doses of lithium (eg. 150 to 200 mg per day) may cause serious side effects, doses below 5 mg per day from most supplements or from tap water are unlikely to cause harm in most people.
Curcumin, found in the spice turmeric, may benefit the brain and even protect against dementia, but the evidence is weak, partly due to the fact that most past clinical trials used a form of curcumin that wasn’t easily used by the human body. Both dietary curcumin, often found in curry, and curcumin supplements appear safe for most people.
High-flavanol Cocoa or Chocolate
Flavanol-rich cocoa or chocolate might improve cognition function in elderly people but potential benefits are selective to specific aspects of cognition. Whether it can protect against dementia itself is less clear. On the plus side, safety concerns are generally limited to the caffeine and theobromine content, as well as the high caloric content.
Vitamin C and E Supplements
Vitamins C and E are essential for proper health. Some people with Alzheimer’s disease and dementia have low levels of these vitamins, although it has not been proven that the lack of vitamins caused their disease. Observational studies suggest that increasing dietary intake of vitamins C and E might protect against dementia although vitamin C and E supplements may not offer the same protection. Both vitamins are generally safe for supplementation in healthy people, although some studies have linked vitamin E supplementation with an increased risk of dying. Maintaining healthy levels of vitamins C and E in the diet may be better than supplementation for most people.
Vitamin D is essential for human health and may be important in aging and age-related cognitive decline. People get vitamin D from food and from their skin, which produces vitamin D when stimulated by sunlight. Many animal studies and observational studies in humans suggest low vitamin D levels are associated with age-related diseases, lifespan and mortality but these studies do not prove that vitamin D deficiency actually causes these diseases. Vitamin D supplements are generally considered safe when used correctly by healthy people. Large randomized trials are now needed to clearly define the role of vitamin D in human health.
Magnesium is critical for brain health and is mostly obtained through a healthy diet. Some research has shown lower magnesium levels in patients with Alzheimer’s disease, but there is little evidence that supplementation can prevent or treat dementia. Magnesium supplementation in moderation appears to be safe for most people, with some notable exceptions (including a warning for people with compromised kidney function).
Magnesium is normally obtained through food and is essential for brain health. High dietary intake of magnesium has been linked to a lower risk of dementia while some Alzheimer’s patients have low blood and brain levels of magnesium. While dietary magnesium is very likely safe, magnesium supplements carry their own risks.
Cerebrolysin is a mixture of peptides purified from pig brains and is approved in many European and Asian countries for the treatment of stroke, traumatic brain injury and dementia; however it is not approved for use in the United States. It appears safe for short-term use (up to 3 years) and results from several clinical trials suggest it might offer small improvements to symptoms of Alzheimer’s disease and vascular dementia. It remains unknown if Cerebrolysin might prevent dementia, slow aging or lower risk of mortality.
Resveratrol is an antioxidant found in foods such as grapes, berries, peanuts, chocolate and red wine. Although it is still unclear whether resveratrol has any benefits in healthy people, some small clinical trials suggest that it may help those with certain health conditions. Taking resveratrol supplements is generally regarded as safe although long-term use has not been studied.
Extracts of the plant Rhodiola rosea are traditional herbal medicines intended to enhance performance and reduce fatigue. They have also been hypothesized to alleviate a wide range of conditions including altitude sickness, depression, influenza, and cancer, but the evidence for all of these claims is weak, contradictory and inconclusive. Rhodiola supplements are considered generally safe for healthy people.
Buckminsterfullerene (C60) is a molecule with unusual properties that was discovered in the late 1980’s and is being investigated for cancer treatments, skin care carbon nanotubes, and other applications. Several laboratory studies suggest that the water-soluble form of C60 may have neuroprotective properties and the non-hydrated forms dissolved in olive oil might extend lifespan. However, these claims have never been tested in humans. Similarly, the safety of C60 and its derivatives have never been tested in humans.
Coenzyme Q10 (CoQ10) is a natural vitamin substance that is essential for energy production in cells. While CoQ10 supplementation has shown beneficial results in animal models of neurodegenerative diseases like Alzheimer’s, it has failed in human clinical trials. There is no evidence that CoQ10 supplementation can increase human lifespan. Very few adverse effects have been reported with CoQ10 supplementation and it is generally considered safe for most people.
Fisetin is naturally found at very low levels in some plants, fruits and vegetables. Some cell and animal studies suggest that fisetin may protect brain cells from damage and potentially reduce diabetes and cancer risk, but there is no evidence yet that it does the same in humans. While concentrated fisetin is commercially available as a dietary supplement and often marketed as a “memory enhancer”, almost nothing is known about how it acts in the human body to cause either harm or benefit.