Researchers from the Ben-Gurion University of the Negev in Israel conducted a clinical trial to investigate the impact of a Mediterranean diet on brain aging. Their findings, published in the journal Clinical Interventions in Aging, revealed that consuming a diet rich in fresh vegetables, seafood, and whole grains, and low in processed foods, can slow the signs of accelerated brain aging typically seen in obesity. The researchers found that even with as little as a 1% loss in body weight, the brain scans of participants after 18 months appeared almost 9 months younger than expected, compared to estimates of their brain’s chronological age.
The Difference between Biological and Chronological Age
The difference between biological and chronological age is that biological aging can be found etched onto the ends of your chromosomes, dotted along your DNA, or in the loosening connections of your brain. While feeling younger than your years may be a common occurrence, research shows that your body’s biological age is much more than a feeling. A growing body of research suggests that biological aging brought on by stressful events could be reversible, and this new study shows that improving your diet may be one of the simplest options to improve body condition, irrespective of the years.
The researchers imaged the brains of 102 participants who were part of a larger clinical trial conducted at one workplace in Israel. Brain scans were taken once before the trial began and again after 18 months, along with a battery of tests of liver function, cholesterol levels, and body weight. The groups ate one of three diets: a Mediterranean diet with lots of nuts, fish, and chicken instead of red meat; a Mediterranean diet with a few added extras such as green tea for the polyphenols; or a diet based on healthy dietary guidelines.
Estimates of brain age were based on an algorithm that had been trained on brain scans from a separate cohort of nearly 300 people, with the model accurately predicting age from measures of brain connectivity. On average, people in the trial lost around 2.3 kilograms. For every 1 percent of body weight lost, the participants’ brains appeared almost 9 months younger than their chronological age, the researchers found.
Limitations and Future Research
The study has some limitations. Most of the participants were men, and they filled out online surveys about their diet and lifestyle habits, meaning the data may be skewed by what they could recall or chose to report. Participants’ activity levels at work were taken into account, and they also received a free gym membership as part of the trial, so exercise was a factor too.
Future research needs to investigate whether changes in brain connectivity translate to improvements in brain function. The brain is a complex web of flexible connections we are only just beginning to map out, though a recent review hints at the Mediterranean diet having a positive effect on memory in older people. Signs of slowed brain aging were also associated with lower levels of liver fat and improved lipid profile, but these changes could be superficial or short-lived.
Lead author and neuroscientist Gidon Levakov of Ben-Gurion University of the Negev in Israel states that the study highlights the importance of a healthy lifestyle, including lower consumption of processed food, sweets, and beverages, in maintaining brain health. Although these findings are from a clinical trial where participants were randomly ‘prescribed’ a diet to follow, there are a few other limitations worth digesting. Past research has uncovered how the good fats of a Mediterranean diet work on a cellular level. Still, it has also exposed clear discrepancies in who reaps the health benefits of a diet rich in Mediterranean staples. People with well-paying jobs and higher education who could afford to buy lots of fish and whole grains saw greater improvements in cardiovascular health than those on low incomes – even if their adherence to the diet was the same.