Study links nutrients in blood to better brain connectivity, cognition in older adults

University of Illinois, December 20, 2022

A new study links higher levels of several key nutrients in the blood with more efficient brain connectivity and performance on cognitive tests in older adults. The study, reported in the journal NeuroImage, looked at 32 key nutrients in the Mediterranean diet, which previous research has shown is associated with better brain function in aging. It included 116 healthy adults 65-75 years of age. "We wanted to investigate whether diet and nutrition predict cognitive performance in healthy older adults," said University of Illinois postdoctoral researcher Christopher Zwilling, who led the study with U. of I. psychology professor Aron Barbey in the Beckman Institute for Advanced Science and Technology. The analysis linked specific patterns of a handful of nutrient biomarkers in the blood to better brain health and cognition. The nutrient patterns included omega-3 fatty acids, which are abundant in fish, walnuts and Brussels sprouts; omega-6 fatty acids, found in flaxseed, pumpkin seeds, pine nuts and pistachios; lycopene, a vivid red pigment in tomatoes, watermelon and a few other fruits and vegetables; alpha- and beta-carotenoids, which give sweet potatoes and carrots their characteristic orange color; and vitamins B and D. The researchers relied on some of the most rigorous methods available for examining nutrient intake and brain health, Barbey said. Rather than asking participants to answer food-intake surveys, which require the accurate recall of what and how much participants ate, the team looked for patterns of nutrient "biomarkers" in the blood. The team also used functional magnetic resonance imaging to carefully evaluate the efficiency with which various brain networks performed. The analysis found a robust link between higher levels of several nutrient biomarkers in the blood and enhanced performance on specific cognitive tests. These nutrients, which appeared to work synergistically, included omega-3 and omega-6 fatty acids, carotenoids, lycopene, riboflavin, folate, vitamin B12 and vitamin D. The analysis also revealed that a pattern of omega-3s, omega-6s and carotene was linked to better functional brain network efficiency. Different nutrient patterns appeared to moderate the efficiency in different brain networks. For example, higher levels of omega-3 fatty acids paralleled the positive relationship between a healthy frontoparietal network and general intelligence. The frontoparietal network supports the ability to focus attention and engage in goal-directed behavior. "Our study suggests that diet and nutrition moderate the association between network efficiency and cognitive performance," Barbey said. "This means that the strength of the association between functional brain network efficiency and cognitive performance is associated with the level of the nutrients."

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Sunlight offers surprise benefit -- it energizes infection fighting T cells

Georgetown University Medical Center, December 20, 2022

Sunlight allows us to make vitamin D, credited with healthier living, but a surprise research finding could reveal another powerful benefit of getting some sun. Georgetown University Medical Center researchers have found that sunlight, through a mechanism separate than vitamin D production, energizes T cells that play a central role in human immunity. Their findings, published in Scientific Reports, suggest how the skin, the body's largest organ, stays alert to the many microbes that can nest there. "We all know sunlight provides vitamin D, which is suggested to have an impact on immunity, among other things. But what we found is a completely separate role of sunlight on immunity," says the study's senior investigator, Gerard Ahern, PhD, associate professor in the Georgetown's Department of Pharmacology and Physiology. "Some of the roles attributed to vitamin D on immunity may be