A new study suggests following a Mediterranean diet rich in vegetables, fish, and whole grains may help slow signs of accelerated brain aging associated with obesity.
Published in April in the journal eLife, the findings show adhering to the Mediterranean diet or dietary guidelines for just 18 months was associated with participants’ brains appearing almost 9 months younger than expected, compared to estimates of their brains’ chronological age.
The results highlight how relatively small improvements in diet quality could lead to better brain health as we age.
Mediterranean Diet Linked to Younger Brain Age
In the study, researchers at Ben-Gurion University of the Negev in Israel analyzed brain scans from nearly 100 employees before and after an 18-month diet intervention program at one workplace.
Participants were randomly assigned to one of three diet groups:
- Mediterranean diet with olive oil and nuts
- Enhanced Mediterranean diet with green tea and polyphenol supplements
- Low-fat diet based on national dietary guidelines
On average, participants lost about 2.3 kg (5 lbs) during the trial period. But surprisingly, those who lost just 1% of their body weight after improving their diet showed differences in brain connectivity that made their brains appear almost 9 months younger than their real age.
The estimates of brain age came from a machine learning algorithm trained on brain scans from about 300 separate individuals. By looking at patterns of brain connectivity, the algorithm can predict a person’s age.
In this study, the participants’ post-diet brains showed connectivity patterns more typical of younger individuals.
“Our findings highlight the potential impact of a healthy lifestyle on preventing accelerated aging,” said senior study author Prof. Uri Nir of Ben-Gurion University.
Diet Improvement May Reverse Biological Brain Aging
The results suggest biological brain aging associated with obesity may be at least partially reversible through modest diet improvements like optimizing vegetable intake and minimizing processed foods.
“Obesity, unhealthy diet and lack of physical activity are associated with accelerated aging and higher risk for various chronic diseases,” said first study author Dr. Gidon Levakov. “Our study underscores the potential of a healthy lifestyle to help reverse signs of accelerated aging.”
Previous research has shown markers of biological aging like shortened telomeres and cellular senescence can be caused by stress, smoking, obesity, and other factors. This in turn is linked to earlier onset of age-related diseases.
But more recent studies indicate biological aging may be slowed or partially reversed through interventions like diet, exercise, and stress reduction techniques.
By showing improved diet led to more youthful brain connectivity patterns, the current findings provide more evidence biological aging is modifiable as we get older.
Limitations and Next Steps
While promising, the study had some limitations. Most participants were men, and diet information was self-reported. The participants also received free gym memberships, so increased physical activity may have contributed to the benefits.
Additionally, it’s unclear if the brain connectivity changes translate to noticeable improvements in cognition or memory. The Mediterranean diet has been linked to better cognitive function in other studies, but more research is needed.
“While many studies have shown positive effects of the Mediterranean diet on cardiovascular health, its effects on brain health are just starting to be uncovered,” said neuroscientist Dr. Lisa Mosconi, who was not involved in the research.
“This study offers important clues on how improving diet quality may benefit the aging brain at a structural level,” she added.
The researchers plan follow-up studies to determine how long the changes persist and whether they continue providing brain benefits years later. They also hope to determine whether results can be replicated in larger groups of men and women from diverse socioeconomic backgrounds.
Healthy Diet Critical for Brain Health at All Ages
While this study focused on older adults, experts say healthy diet habits are important for optimal brain function across the lifespan.
“It’s never too early to start eating for better brain health,” Mosconi said.
She recommends a whole food Mediterranean-style diet with extra emphasis on foods containing beneficial vitamins, minerals, and omega-3 fatty acids that promote neuron growth and connectivity. These include green leafy vegetables, berries, nuts, fish, and olive oil.
Minimizing highly processed foods is also important. Studies show ultra-processed foods now make up more than half of the average American diet, which may negatively impact cognition.
In addition to optimizing nutrition, staying mentally and socially active also helps keep the brain sharp and resilient. But ensuring the brain receives proper physiological nourishment through a healthy diet serves as a critical foundation.
“While genetics plays a role, adopting lifestyle habits that support brain structure and function throughout life holds promise for maintaining brain health into old age,” Levakov said.