Many foods — blueberries, leafy greens, and curcumin (found in the spice turmeric), to name a few — have been studied for their potential cognitive benefit.
These foods were thought to have anti-inflammatory, antioxidant or other properties that might help protect the brain.
So far, there is no evidence that eating or avoiding a specific food can prevent Alzheimer’s disease or age-related cognitive decline.
But scientists continue to look for clues.
One study, based on older adults’ reports of their eating habits, found that eating a daily serving of leafy green vegetables such as spinach and kale was associated with slower age-related cognitive decline, perhaps due to the neuroprotective effects of certain nutrients.
Research has also shown that eating a diet that includes regular fish consumption is associated with higher cognitive function and slower cognitive decline with age.
Another recent study, in mice, found that consuming a lot of salt increased levels of the protein tau, found in the brains of people with Alzheimer’s, and caused cognitive impairment.
What About Vitamins and Supplements?
Observational studies and clinical trials have looked at many over-the-counter vitamins and dietary supplements, including vitamins B and E and gingko biloba, to prevent Alzheimer’s disease or cognitive decline.
The idea is that these dietary add-ons might attack oxidative damage or inflammation, protect nerve cells, or influence other biological processes involved in Alzheimer’s.
Despite early findings of possible benefits for brain health, no vitamin or supplement has been proven to work in people. Overall, evidence is weak as many studies were too small or too short to be conclusive.
Take DHA (docosahexaenoic acid) for example. Studies in mice showed that this omega-3 fatty acid, found in salmon and certain other fish, reduced beta-amyloid plaques, a hallmark of Alzheimer’s.
However, clinical trials in humans have had mixed results.
In a study of 485 older adults with age-related cognitive decline, those who took a DHA supplement daily for 24 weeks showed improved learning and memory, compared to those who took a placebo.
Another study of 4,000 older adults — conducted primarily to study eye disease — concluded that taking omega-3 supplements, alone or with other supplements, did not slow cognitive decline.
At this time, no vitamin or supplement is recommended for preventing Alzheimer’s or cognitive decline.
Although widely available from drugstores and on the internet, many of these have not been tested for their effects on thinking.
Their safety and effectiveness are largely unknown, and they may interact with other medications. (Note: A deficiency in vitamin B12 or folate may cause memory problems that are reversible with proper treatment.)
For more information, visit the National Center for Complementary and Integrative Health and the U.S. Food and Drug Administration.
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