As research continues to reveal connections between what we eat and how our brains function, you may be seeking practical guidance on dietary choices that support cognitive health. Keren Zhou, MD, an Endocrinologist in the department of Diabetes, Endocrinology and Metabolism at Cleveland Clinic, shares evidence-based recommendations for protecting and improving brain health through nutrition—from the power of the MIND diet to the importance of avoiding ultra-processed foods.
Read the interview with Dr. Zhou below.
WAM: What specific dietary guidelines do you offer to patients who are particularly interested in protecting or improving brain health? For someone just starting to make dietary changes for brain health, what would you recommend as the most impactful first steps they could take?
Dr. Zhou: Current and emerging evidence suggests that the MIND diet, which stands for Mediterranean-DASH Intervention for Neurodegenerative Delay, is probably one of the best diets for brain health. The plan, which is a hybrid of the Mediterranean and DASH diets, emphasizes green leafy vegetables, berries, nuts, whole grains and sources of lean protein. Additionally, both the Mediterranean and DASH diets separately have been shown to improve cognitive functioning in adults. For individuals who are looking to take the first steps, I would suggest incorporating an additional serving of leafy greens a day, incorporating more whole grains as opposed to refined grains and adding a serving of fish 2-3 times a week.
WAM: How does diet affect the structure and function of the brain?
Dr. Zhou: Many nutrients such as omega-3 fatty acids, choline and folate are integral for initial brain development in utero and during early childhood. As we age, various macro- and micronutrients remain critical in the optimal functioning of the brain and the ability to generate new neurons and maintain brain plasticity. Conversely, diets high in processed sugars and saturated fats are known to be associated with chronic inflammation in the brain and accelerated neurodegeneration.
WAM: What specific nutrients or compounds in brain-healthy foods have the strongest evidence for neuroprotection?
Dr. Zhou: While there is no specific vitamin or supplement that is currently recommended for preventing Alzheimer’s or cognitive decline, it is certainly an area of active study. Omega-3 fatty acids, in particular DHA, intake has been associated with reduced cognitive decline and potentially improved cognitive function. Similarly, polyphenols, found in berries, green tea, dark chocolate, amongst other foods, appear to improve blood flow to the brain and reduce oxidative stress. Certain vitamins such as vitamins C and E have been associated with lower risk of Alzheimer’s as well.
WAM: There’s a lot of discussion about ultra processed foods. What are they, and is there a reason to think that eliminating them from our diets would benefit brain health?
Dr. Zhou: Ultra processed foods are formulated products made from substances extracted from food or synthesized in a lab. These food products are quite altered from their whole food state and often contain high levels of salt and sugar. Examples of this include chips, soda, instant noodles, hot dogs, amongst many others. There is good data suggesting that people who eat a diet high in ultra processed foods have a greater risk of cognitive impairment over the long run. For example, a 2022 JAMA Neurology study suggests that those who consumed greater than 20% of their calories from ultra processed foods had a significantly greater risk of cognitive decline over an average 8 years of follow up than those who did not reach that threshold.
WAM: At what age should people start focusing on brain-healthy nutrition? Is it ever too late to see benefits from dietary changes?
Dr. Zhou: Really there is never too early a time – Even in childhood there is likely an impact on future brain health. But, similarly, it is never too late to see benefit from dietary changes. Data from older adults suggest that one can experience benefits in improved memory, attention and reduction in cognitive decline just through dietary change.
WAM: For patients who already show early signs of cognitive decline, can dietary interventions still make a meaningful difference, or are they primarily preventive?
Dr. Zhou: There are studies that suggest in those with mild cognitive impairment, or early cognitive decline, that diets like the Mediterranean and MIND diets can slow down the decline. This improvement may even be present if the adherence is moderate as opposed to completely on the diet.