The Mediterranean diet may slow brain aging, MRI study shows
Maintaining healthy blood sugar levels long-term could be the key to slowing brain aging, according to new MRI data.
In one of the largest and longest studies of its kind, the DIRECT PLUS trial, provided detailed new insights into how diet impacts brain health. The study, which included nearly 300 participants and took place over a period of 18 months, linked specific eating habits to decreased brain age. Specifically, experts found that those who followed the Green Mediterranean diet (Green-Med), which incorporates more plant-based foods and into the traditional Mediterranean diet, showed the most ideal brain structure and function in areas considered more vulnerable to age-related atrophy.
“Maintaining low blood sugar levels, even within the normal range, shows promise for preserving a younger brain, especially when combined with a healthy diet and regular physical activity,” lead researcher, Iris Shai, from Ben-Gurion University and an adjunct professor at Harvard University, notes. “Specifically, polyphenols found in plant-based foods may cross the blood-brain barrier and help reduce brain inflammation, which is crucial for memory.”
Researchers compared the imaging results of three different groups of participants—those who followed the Green-Med way of eating, those who were on a Mediterranean diet and those who abided by general healthy dietary guidelines. The Green-Med group also routinely consumed green tea and Mankai duckweed shakes. Participants followed these meal plans for a total of 18 months and also completed baseline and intermittent bloodwork and imaging throughout the duration of the study.
The team used hippocampal occupancy (HOC) score (hippocampal and inferior lateral-ventricle volumes ratio) as a neurodegeneration marker and brain-age proxy. Higher HOC deviations indicated that an individual had a lower brain age.
Those with higher HOC deviations had lower body weight, waist circumference, blood pressure and insulin and HbA1c levels. Over the 18-month study period, those who had the greatest decline in HbA1c levels showed more substantial changes in the thalamus, caudate nucleus and cerebellum on imaging. These changes were most notable in those who followed both the Mediterranean and Green-Med diets, though the latter showed the most significant HOC deviations.
The Mediterranean diet has been praised by numerous experts as the most beneficial for cardiovascular health, but less is known about its impact on cognitive health. Researchers involved in this study suggested that, although more research is needed to understand the mechanisms that underly the diet’s impact on brain aging, their findings indicate that the way of eating could represent a simple lifestyle change that could have significant benefits for cognitive health.
"This trial offers a safe approach to potentially slow down our brain aging—by adopting the components of a green-Mediterranean diet,” suggests first author Dafna Pachter, PhD.
Learn more about the study’s results here.
In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She began covering the medical imaging industry for Innovate Healthcare in 2021.