Mediterranean diet: Key nutrients may help slow brain aging

This study was a cross-sectional study involving one hundred adults between the ages of 65 and 75. All participants were healthy and showed no evidence of cognitive impairment. Participants underwent several tests, including MRI scans, mental tests, and bloodwork.

During the study, researchers examined 139 variables of brain health, including markers of brain metabolism, function, and structure.

Researchers identified two brain health phenotypes: delayed brain aging and accelerated brain aging. Those in the delayed aging group had a younger brain age than those in the accelerated brain aging group.

Participants also underwent several tests to look at things like intelligence, executive function, and memory. The results pointed to better cognitive function for participants in the delayed brain aging group.

Next, researchers looked at nutrient profiles via blood samples for participants in the delayed brain aging group.

This group had higher levels of 13 nutrients than those in the accelerated phenotype.

These nutrients included several fatty acids, the carotenoids lutein and zeaxanthin, vitamin E, and choline. Two of the noted fatty acids were omega-3 polyunsaturated fatty acids called alpha-linolenic acid (ALA) and eicosapentaenoic acid (EPA).

This nutrient profile seems to have a distinct impact on brain aging, independent of specific demographic measurements, body sizes and proportions, and physical fitness levels.

Researchers were also able to account for covariates like sex, income, body mass index (BMI), and education level. The results indicate a particular nutrient profile that may help slow brain aging.

The study authors suggest that the Mediterranean diet may be one of the most helpful ways to ensure consumption of these nutrients. The Mediterranean diet includes lots of fruits and vegetables and low to moderate amounts of components like fish, dairy, eggs, and poultry.

Non-study author Sarah Wagner, a dietitian with Memorial Hermann Health System, noted the following to MNT:

“The Mediterranean diet is a big name when talking about reducing risk of cardiovascular disease and premature death. Of course, most people don’t just want to live longer physically but also want to preserve cognitive function as they age. The nutrients called out in this study are commonly found in a Mediterranean diet pattern, suggesting a Mediterranean diet (or other plant-forward diet) is not only beneficial for our physical health but also for our cognitive health.”

Despite the promising implications this study has a few limitations. First, it cannot establish causality. Second, it only included a small number of participants, all of whom were white, indicating that future research can consist of a more extensive, more diverse data set.

Further, the research only included adults between ages 65 and 75, so future studies could include data from older age groups as well. The results also don’t negate the importance of other nutrients to brain function.

Researchers further acknowledge that certain nutrients are not as well understood, so more research is needed to examine some of the underlying mechanisms involved.

Future research can also examine how certain nutrients affect the trajectory of brain aging.

Barbey noted the following areas for continued research:

“Despite the promise of this work, further research is necessary to apply these findings to the context of public health. Observational studies like this one need to be followed by randomized controlled trials to confirm the effectiveness of the identified nutrient profile in promoting brain health. Additionally, further research is needed to understand the specific mechanisms by which this nutrient profile may influence brain aging. Finally, longitudinal studies are needed to assess the long-term effects of dietary interventions based on this profile.”

The results of this study do point to the potential benefits of certain nutrients. Researchers noted several sources of these nutrients within the study.

For example, carotenoids are phytopigments that give certain foods vibrant colors. A few sources of carotenoids include:

• bell peppers
• tomatoes
• broccoli
• carrots

Common sources of vitamin E include green leafy vegetables, nuts, and seeds. Choline is common in eggs, poultry, fish, cruciferous vegetables and certain beans.

Wagner offered similar dietary guidance in her comments and made the following recommendations:

“If you’re an oatmeal fan, add flax meal, chia seeds, and English walnuts to increase the fatty acid ALA. Have a fatty fish like salmon, herring, or sardines in your dinner rotation a couple times a week for more EPA. Nuts and dairy products are good sources of the other fatty acids mentioned in the study. Yogurt or lightly salted nuts can make great snacks. You can also make a creamy salad dressing with yogurt and throw some chopped nuts onto a salad. Nuts, seeds, and seed oils are good foods to include for more vitamin E also. Think about getting more color for more carotenoids. Vibrant foods like leafy greens, bell peppers, melon, tomatoes, and carrots are good foods for carotenoids. Eggs and other animal proteins are good sources of choline, and so are plant foods like potatoes and soybeans.”

Anyone interested in including more of these nutrients in their diet may benefit from working with a licensed professional, such as a registered dietitian nutritionist.