According to new research from the Ben-Gurion University of the Negev, switching to a Green Mediterranean Diet positively affects brain health. Weight loss attenuated brain ageing in a sub-study of the DIRECT-PLUS trial.
DIRECT PLUS was a large-scale, long–term clinical trial over 18 months among 300 participants.
The sub-study was conducted by Professor Galia Avidan of the Department of Psychology and Dr Gidon Levakov, a former graduate student at the Department of Cognitive and Brain Sciences.
The larger study was led by Professor Iris Shai of the Ben-Gurion University of the Negev, an adjunct Professor from the Harvard School of Public Health and an honorary professor at the University of Leipzig, Germany, along with her former graduate student Dr Alon Kaplan, and colleagues from Harvard and Leipzig Universities.
Obesity is linked with the brain ageing faster than would normally be expected. Researchers can capture this process by calculating a person’s ‘brain age’ – how old their brain appears on detailed scans, regardless of chronological age. This approach also helps to check how certain factors, such as lifestyle, can influence brain ageing over relatively short time scales.
Levakov, Kaplan, Shai and Avidan studied 102 individuals who met the criteria for obesity. The participants received a brain scan at the beginning, and the end of the program; more tests and measurements were also conducted at these times to capture other biological processes affected by obesity, such as liver health.
They used the brain scans taken at the start and end of the study to examine the impact of lifestyle intervention on the ageing trajectory. The results revealed that a reduction in body weight of 1% led to the participants’ brain age being almost nine months younger than the expected brain age after 18 months.
This attenuated ageing was associated with changes in other biological measures, such as decreased liver fat and liver enzymes. Increases in liver fat and the production of specific liver enzymes were previously shown to affect brain health in Alzheimer’s disease negatively.
“Our study highlights the importance of a healthy lifestyle, including lower consumption of processed food, sweets, and beverages, in maintaining brain health,” says Dr Levakov.
“We were encouraged to find that even a weight loss of 1% was sufficient to affect brain health and lead to a 9-month reduction in brain age,” says Professor Avidan.
The findings show that lifestyle interventions promoting weight loss can benefit the ageing trajectory of the brain seen with obesity. The next steps will include determining whether slowing down obesity-driven brain ageing improves patient clinical outcomes.
In addition, the study shows a potential strategy to evaluate the success of lifestyle changes on brain health. With global rates of obesity rising, identifying interventions that positively impact brain health could have important clinical, educational, and social impacts.
The DIRECT-PLUS trial research team was the first to introduce the green-Mediterranean, high polyphenols diet concept. This modified Mediterranean diet is distinct from the traditional Mediterranean diet because of its more abundant dietary polyphenols (phytochemicals, secondary metabolites of plant compounds that offer various health benefits) and lower red/processed meat.
On top of a daily intake of walnuts (28 grams), the green-Mediterranean dieters consumed three–four cups of green tea and one cup of Wolffia-globosa (Mankai) plant green shake of duckweed per day over 18 months. The aquatic green plant Mankai is high in bioavailable iron, B12, 200 kinds of polyphenols and protein and is a good meat substitute.