What we eat may influence how well our brains age. That idea has been around for decades, but new research from Japan is giving it fresh momentum. In one of the largest nutrition studies of its kind, scientists tracked more than 160,000 adults for 15 years and found that people who consumed more riboflavin—vitamin B2—were less likely to develop dementia.
Riboflavin fuels the brain’s energy factories and supports cellular repair, both of which tend to falter with age. The study, published in Frontiers in Nutrition, has its limitations—it relied on a single day of self-reported food data—but the findings fit a larger pattern. A growing body of evidence suggests that certain vitamins and nutrients may help buffer the brain against age-related decline.
There’s no silver bullet, but several supplements have shown measurable promise.
Multivitamins: Small Gains That Add Up
Daily multivitamin use appears to slow the brain’s natural aging process. In large placebo-controlled trials, including one led by researchers at Mass General Brigham, older adults taking multivitamins performed as if their brains were about two years younger than those on placebo.
Multivitamins don’t work magic—they simply help fill the small nutritional gaps that can accumulate over time. They deliver a steady mix of micronutrients such as B vitamins, antioxidants, and minerals that support neurotransmitter function and protect brain cells from oxidative stress. Think of them as maintenance rather than medicine.
B Vitamins: Repairing the Brain from Within
Folate (B9), B6, and B12 have attracted special attention because they lower homocysteine, an amino acid linked to brain shrinkage and dementia risk. Studies from the National Center for Complementary and Integrative Health and UCSF suggest that these B vitamins can slow cognitive decline in both healthy adults and those with mild cognitive impairment.
Interestingly, the benefits seem greatest for people who start out deficient or who combine B vitamins with other nutrients like magnesium, vitamin D, and antioxidants. For those who already have normal B12 levels, extra supplementation probably won’t move the needle much.
Omega-3 Fatty Acids: Brain Food from the Sea
Of all the nutrients studied for brain health, omega-3 fatty acids—especially DHA—stand out. DHA forms part of every neuron’s membrane and helps brain cells communicate smoothly. Populations that eat more fatty fish consistently show lower rates of cognitive decline.
Clinical trials, however, have been less dramatic. For people who already eat fish several times a week, omega-3 supplements add little benefit. But for those who rarely do, taking fish oil or algae-based DHA may help preserve memory and attention.
Antioxidants: Vitamins C and E Work Better Together
When combined, vitamins C and E appear to offer mild protection against Alzheimer’s. Together they neutralize free radicals, unstable molecules that chip away at brain cells over time. Still, more isn’t always better—very high doses can backfire. A diet rich in fruits, vegetables, and nuts provides a safer and more effective source of these antioxidants than pills alone.
Other Possibilities—and Cautions
Magnesium (especially in the form magnesium L-threonate) and phosphatidylserine have both shown hints of cognitive benefit in smaller studies. L-theanine, an amino acid in green tea, may sharpen focus and calm the mind, though its long-term effects on brain aging are unclear.
Meanwhile, once-hyped supplements like ginkgo biloba, turmeric, and chromium have repeatedly failed to show strong or consistent effects in controlled trials.
The Bottom Line
Supplements can support brain health, but they’re not a shortcut. Their effects vary with age, diet, genetics, and baseline nutrient levels. For most people, the strongest defense against Alzheimer’s still looks familiar: daily movement, mental challenge, social connection, quality sleep, and a diet rich in plants and fish.
The new riboflavin study is a reminder that even small nutritional choices matter. Protecting the brain may not begin in a lab—it begins at the dinner table.