Urology Pearls: Matter over mind

Aug 22, 2023

Shahar Madjar, MD

Can the MIND diet — a diet that includes foods and nutrients that are considered beneficial to brain health — protect against cognitive decline the likes of which is seen in patients with Alzheimer’s disease?

Dr. Lisa L. Barnes from Rush University’s Alzheimer’s Disease Center and her colleagues examined the possible effect of the MIND diet on cognitive decline.

The MIND diet is a modified hybrid of two different diets: the Mediterranean diet and the DASH diet (MIND stands for Mediterranean-DASH Intervention for Neurodegenerative Delay; and DASH stands for Dietary Approaches to Stop Hypertension).

I have written here before about the two diets. In brief: The Mediterranean diet typically includes: plenty of fruits, vegetables, bread and other grains, potatoes, beans, nuts and seeds; olive oil; and low to moderate amounts of dairy products, eggs, fish and poultry. The DASH diet is designed to reduce high blood pressure (hypertension) and is low in sodium (salt) and in saturated fat; it is rich in potassium, calcium, magnesium, fiber and protein. Doctors and scientists believe, based on extensive research, that both diets have beneficial effects on cardiovascular morbidity and on general health.

The idea of a “brain-friendly” diet stems from observational studies and from studies that suggest a link between the consumption of green leafy vegetables, nuts, berries, and olive oil and the reduction in pathological changes in the brain that are typical of Alzheimer’s disease. Proponents of the idea propose that certain food items exhibit antioxidant and anti-inflammatory properties that promote brain functioning and combat cognitive decline.

Dr. Barnes enrolled a total of 604 participants in her MIND study. The participants were older (65 or older), obese individuals with a family history of dementia who consumed “suboptimal diet.” Older age, obesity, and suboptimal diet are all known risk factors for the development of cognitive decline and Alzheimer’s disease. None of the participants in this study, though, had cognitive impairment at the beginning of the study, and the goal of the study was to see whether the MIND diet can alter the chance of developing such a condition. The researchers evaluated the participants’ cognitive status and the quality of their diet using validated questionnaires.

The researchers then randomly divided the participants into two groups. One group was assigned to the MIND diet and the other served as a control group. The MIND diet group received a monthly supply of blueberries, mixed nuts, and extra virgin olive oil. The participants in the control-diet group received instead monthly $30 gift cards. In addition, the researchers counseled participants in both groups to conform to a diet with mild caloric restriction.

The participants were then followed over a 3 year period with 93.4% of the participants adhering to the study protocol for the entire time. At 3 years, individuals in both groups showed similar weight loss (4.8-5 kg). In addition, both groups showed some improvement in their global cognition score but there was no significant difference between the groups. And when the researchers examined MRI (magnetic resonance imaging) images of the participants’ brains, they also found no difference in measures such as white-matter hyper-intensities, hippocampal volumes, and total gray- and white-matter volumes.

In summary, after 3 years, there was no significant difference between the groups. Whether the participants were on the MIND diet or in the control group, they lost the same amount of weight, their cognition score improved to the same extent, and their brain anatomy looked similar.

Why did the participants lose weight? Perhaps because both groups were instructed to reduce their caloric intake. Why did their MRI images look the same? Perhaps because it takes more than a daily handful of blueberries and a tablespoon of olive oil to alter the anatomy of our brains. Why wasn’t there a dramatic effect on the participants cognition score? Perhaps it’s because the participants weren’t followed for a long enough period (who knows, perhaps 13 years of the MIND diet would have resulted in clearer differences). And perhaps it’s because the MIND diet just doesn’t work better than mild caloric restriction alone, at least not over a short period of 3 years.

Researchers, doctors, and patients want to see positive results–interventions that clearly demonstrate a positive impact on quality of life and on longevity. It is important to realize that research studies with negative results, such as this one, are also important. They tell us what interventions may be insufficient to make a true impact. They free us from false hopes and drive us to seek other, better solutions.

EDITOR’S NOTE: Dr. Shahar Madjar is a urologist at Aspirus and the author of “Is Life Too Long? Essays about Life, Death and Other Trivial Matters.” Contact him at [email protected].

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