UNL researchers link healthy brain aging to nutritional profile

Scientists often study these patterns by tracking participants’ diets through questionnaires. Such studies have linked a Mediterranean diet focused on plant-based foods and healthy fats—vegetables, fruit, whole grains and extra virgin olive oil—with improved physical health outcomes, including reduced cardiovascular risk.

Questions remain about whether diet and nutrition can also promote brain health. The options so far to avoid accelerated brain aging are to avoid risk factors such as high blood pressure, alcohol and smoking.

Now a new study led by a University of Nebraska-Lincoln researcher has identified a specific nutritional biomarker profile in healthy adults that is associated with healthy brain aging. And while the researchers did not specifically investigate the Mediterranean diet, the nutrient profile they identified shares some nutrients with the common diet.

“We identified specific patterns of nutritional biomarkers associated with healthy brain aging,” said Aron Barbey, director of UNL’s Center for Brain, Biology and Behavior. “And when we looked at those biomarker patterns, we found that there were also nutrients that you would commonly find in the Mediterranean diet.”

The study, recently published in Nature Publishing Group Aging, enrolled 100 healthy adults between the ages of 65 and 75. The other members of the research team were Jisheng Wu, a doctoral student at UNL, and Christopher Zwilling, a research scientist at the University of Illinois at Urbana-Champaign.

In it, the researchers combined brain imaging measures of brain structure, function and metabolism with cognitive assessments that measured intelligence, executive function and memory. Those measures showed two types of brain aging among the participants – accelerated and slower than expected – compared to the participants’ chronological age. The difference in brain age between the two groups was 5.4 years, a statistically significant margin.

But instead of using so-called food frequency questionnaires to characterize the dietary patterns of the participants, the researchers assessed the nutritional status of the participants who fell into the delayed brain aging group using biomarkers in their blood.

Barbey noted that the questionnaires, traditionally used to characterize dietary patterns, can be quite valuable when it comes to describing individual diets. But they have limitations because people are usually unable to accurately recall the foods – or amounts of food – they eat each day. Different people also metabolize and absorb nutrients differently, and foods themselves can have different nutrient density depending on how they were grown, harvested and prepared.

As a result in recent years researchers have paired questionnaires with blood-based biomarkers that allow researchers to quantify the nutrient content of a participant’s blood.

“That provides a more direct measure of that person’s nutritional status,” Barbey said.

In the study, those in the delayed brain aging group had greater concentrations of 13 key nutrients compared to the accelerated brain aging group.

The nutritional profile included several categories of nutrients related to healthy brain aging: seven fatty acids, three antioxidants and carotenoids, two forms of vitamin E and choline.

Dietary sources of these nutrients include fish and shellfish, as well as many seeds, nuts and seed oils and a variety of colorful fruits and vegetables. At least one type of fatty acid on the list comes from dairy products. Animal-based proteins such as meat, poultry, fish and eggs are significant sources of choline, along with cruciferous vegetables such as broccoli and cauliflower and certain beans.

“This is very positive evidence to support the type of recommendations that have been made,” said Barbey. “The Mediterranean diet is one broad dietary pattern that includes some of these nutrients that we observed in our study.”

But Barbey emphasized that the study is an observational study that requires randomized controlled trials to determine whether giving participants specific foods and increasing nutritional biomarkers would have beneficial effects on their cognitive performance and brain health. This, in turn, could lead to nutritional interventions designed to promote healthy brain aging.

Meanwhile, there is great scientific and medical interest in understanding the impact of nutrition on brain health, he said.

The National Institutes of Health recently launched a 10-year strategic plan to significantly accelerate nutrition research. And Barbey is co-editing an upcoming special collection for the Journal of Nutrition, “Nutrition and the Brain – Exploring Ways to Optimize Brain Health through Nutrition.” Articles will begin to be published next year.

“What we are all trying to do in the nutritional sciences is that evidence-based research can lead to effective public policy recommendations about diet and nutrition and how that can promote health ,” Barbey said. “But unfortunately, more research is needed to reach that stage.”