What Does A Brain Healthy Diet Look Like?
Author: Dr. Stephen Chaney

Age-related cognitive decline is increasing at an alarming rate. For example:
- Newly diagnosed cases of Alzheimer’s disease in Americans over 65 reached 6.5 million in 2022.
- That’s expected to double by 2060.
We have known for years that a whole food, primarily plant-based diet significantly reduces the risk of cognitive decline and Alzheimer’s.
But in our 20s and 30s we tend to ignore that advice. We feel immortal. Aging is something that affects our grandparents – not us.
When we reach our 40s and 50s reality kicks in. Some of our parents, aunts, and uncles start to show symptoms of cognitive decline. Some of our grandparents are suffering from dementia and Alzheimer’s. Maybe we aren’t immortal.
We start to think about changing to a healthier diet and lifestyle. But then the troubling thoughts creep in. “Is it too late? Should I have made those changes in my 20s? Has that ship already sailed?”
A recent study (Y Song et al, Alzheimer’s & Dementia, 2023) was designed to answer that question
How Was This Study Done?
The authors used data from the New York University Women’s Health Study. They studied 5116 women (average age = 46) who enrolled in the study between 1985 and 1991 and were followed for an average of 33 years (average age at the end of the study = 79).
At the beginning of the study, each participant filled out a questionnaire about demographics (age, gender, ethnicity, income, education, and marital status), physical activity, reproductive history, cancer history, and medication use. They also filled out a food frequency questionnaire.
Using the foods reported in the food frequency questionnaires, the scientist rated each woman with respect to adherence to the DASH diet. The women were then separated into quartiles based on their adherence to the DASH diet.
The participants filled out follow-up questionnaires every 3-5 years. Those who did not return the questionnaires were contacted by phone. The last two follow-up questionnaires included a survey of subjective cognitive complaints (SCCs) such as:
- Recent changes in the ability to remember things.
- Difficulty remembering recent events.
- Difficulty remembering a short list of items, such as a shopping list.
- Difficulty understanding or following spoken instructions.
- Difficulty following a group conversation or a plot in a TV program.
- Difficulty navigating familiar streets.
Previous studies have shown that the SCCs survey is an accurate predictor of future dementia and Alzheimer’s.
Finally, the scientists looked at the correlation between adherence to the DASH diet at age 46 with the number of subjective cognitive complaints at age 79.
Is It Too Late To Save Your Mind?
This is what the authors reported:
- There was an inverse association between adherence to foods in the DASH diet (which was called “DASH adherence” by the authors of this study) at age 46 and subjective cognitive complaints (SCCs) at age 79.
- Women in the highest quartile of DASH adherence at age 46 had a 17% reduction in 2 or more SCCs at age 79.
- Every quartile increase in DASH adherence increased the risk of 2 or more SCCs by 7%.
The most frequently reported SCCs were:
- Recent changes in the ability to remember things (40%).
- Difficulty remembering a short list of items (19%).
- Difficulty remembering recent events (17%).
When they looked at the effect of different foods on SCCs (subjective cognitive complaints):
- Consumption of sweets, red meat, and processed meats were associated with an increased risk of SCCs, with sweets having the largest effect.
- Consumption of fruits, vegetables excluding potatoes, legumes and nuts were associated with a decreased risk of SCCs at age 79, with fruits having the largest effect.
There were two other findings of interest:
- The effect of DASH adherence was stronger for Black women than for White women.
- The protective effect of DASH adherence was stronger in women with no previous history of cancer.
The authors concluded, “We found that a higher level of adherence to the DASH diet in mid-life was associated with lower SCCs later in life among women. These findings suggest that improvements in diet quality in mid-life…may have a role in maintaining an optimal subjective cognition among women…”
What Does This Study Mean For You?
Let me start by putting this study into perspective:
- The strength of this study is that it has the longest follow-up period (33 years) and most diverse population of any study on this topic.
- It is consistent with several previous studies with shorter follow-up periods, including the Nurses Health Study which also looked at the effect of DASH adherence at mid-life on SCCs later in life.
- Several studies have shown that the Mediterranean diet protects against cognitive decline. And one recent study showed that mid-life adherence to the Mediterranean diet also offers similar protection against late-life cognitive decline in men.
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- This suggests that any whole food, primarily plant-based eating pattern, is likely to offer similar benefits. That is important because most of us find it easier to focus on foods rather than rigid diets.
- Three studies that just compared DASH adherence and SCCs when subjects were already in their 60s to 90s, found no protective effect of DASH adherence.
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- This suggests that if we wait until old age and are already starting to experience mental decline, switching to a healthier diet may not be as beneficial for protecting our mind as we would like it to be. However, I would never advise anyone to just throw up their hands and say, “I might as well eat what I like and die happy.” That’s because:
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- Healthy dietary patterns have a multitude of health benefits. Cognitive benefits are just the tip of the iceberg.
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- Statistics report averages, and none of us are average. Some people will experience much better cognitive benefits than others by switching to a healthier diet, even if they wait until their “golden years” to do so.
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- There aren’t any clinical studies looking at adherence to a healthy diet in our 20s or 30s and cognitive outcomes in our 70s. The time span is just too great for clinical studies.
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- So, while we can confidently say, “It’s not too late to save your mind” by switching to a healthier diet pattern like DASH or Mediterranean in middle age, there are no clinical studies showing we might get even better results if we started eating healthy in our 20s or 30s. However, logic tells us that is a likely outcome.
- This and most studies on this topic have been done with women. That’s because two thirds of Alzheimer’s patients are women.
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- However, the few studies that have been done with men have reported similar results. So, guys, this affects us too.
- Finally, the fact that DASH adherence was more effective in women who have not had a cancer diagnosis is interesting.
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- In my opinion this is likely because many cancer treatments leave residual “brain fog” and increase the risk of cognitive decline as we age. As someone who spent his life in cancer research, I consider a healthy diet and healthy lifestyle vitally important in helping the body recover from the ravages of cancer treatment.
What Does A Brain-Healthy Diet Look Like?
According to the most recent US News & World Health ratings of the best diets in various categories, the top 4 diets for brain health are:
- MIND diet (The MIND diet combines the best of the Mediterranean and DASH diets with an emphasis on brain healthy foods such as berries.)
- Mediterranean diet.
- Flexitarian diet (a flexible version of a semi-vegetarian diet).
- DASH diet.
My Comments:
- All four diets are whole food, primarily plant-based diets.
- Although the MIND diet was specifically designed for brain health, it does not perform significantly better than the Mediterranean and DASH diets in slowing cognitive decline.
Of course, most people prefer to think in terms of foods rather than diets. In terms of brain-healthy foods, a recent Harvard Health Review suggests these are the foods we should emphasize for brain health:
- Green Leafy Vegetables: Kale, spinach, broccoli, and collards are rich in brain-healthy nutrients like vitamin K, lutein, folate, and beta-carotene.
- Fatty Fish: Salmon, trout, sardines, and mackerel provide omega-3 fatty acids, which are crucial for brain function and for reducing dementia risk.
- Berries: Blueberries, strawberries, and blackberries contain antioxidants that have been shown to delay cognitive decline.
- Nuts and Seeds: Walnuts are high in omega-3 fatty acids (ALA), while others provide vitamin E.
- Healthy Fats: Olive oil is recommended as the primary cooking fat.
- Whole Grains and Legumes: Oats, quinoa, beans, and lentils provide a steady, slow release of glucose for brain energy. Plus, their fiber supports the growth of friendly bacteria that produce brain-healthy nutrients (This is sometimes referred to as the gut-brain axis).
- Other Foods: Avocados (monounsaturated fats), beets (nitrates for blood flow), and cocoa (flavonoids) are beneficial.
The Bottom Line
A recent study showed that adherence to a healthy eating pattern like the DASH diet at middle age can help protect our brain from cognitive decline 30 years later.
For more information on this study and what it means for you, read the article above.
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.
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For more detail about FTC regulations for health claims, see this link.
https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance
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About The Author
Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.
Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.
Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.
Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.
For the past 54 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

























































