Mediterranean diet may reduce brain age, study suggests (but you’ll need to have plenty of walnuts!)

The Mediterranean diet is praised by doctors and scientists for its menu of fruits, vegetables, and whole grains that have been shown to promote heart health.

But now scientists say a slightly modified version — packed with green tea, walnuts, and a green smoothie — improved the brain health of obese people who followed it.

Weighing too much has been linked to faster brain aging than would normally be expected.

Israeli researchers, who recruited more than 100 obese people to follow the diet, found that for every percent drop in their body mass index (BMI), their “brain age” decreased by nine months.

The findings show that it’s vital for brain health to maintain a healthy weight and eat fewer processed foods, sweets and beverages, the researchers said.

The Mediterranean diet – high in healthy fats and protein but low in carbohydrates – has exploded in popularity in recent years with a wealth of studies touting its benefits for longevity, reducing frailty and warding off cancer.

The diet largely consists of avoiding dairy, red meat and alcohol, while eating fruits, vegetables, whole grains, olive oil, oily fish, nuts, seeds and legumes.

A slew of evidence has shown that it can help with weight loss.

Being obese is associated with having an older-looking brain, including a shrinkage of white matter, which aids communication between different brain regions.

Researchers from Ben-Gurion University of the Negev recruited 102 obese volunteers, mostly male and 52 years old on average.

They were asked to follow a “green” Mediterranean diet for 18 months, which included consuming 28 g of walnuts, three to four cups of green tea and a 100 g green shake made with globosa – a type of plant supplement – daily for 18 months.

They were also told to cut out red meat and sweets.

Women were asked to consume no more than 1,200 to 1,400 calories per day, while men stuck to between 1,500 and 1,800 calories per day.

MRI brain scans were taken at the beginning and end of the trial to calculate ‘brain age’ — wait a minute, the brain appears on scans regardless of biological age.

During the study, all participants received free gym memberships and educational sessions that encouraged moderate-intensity exercise.

They were also asked to attend 45 to 60 minute aerobics and resistance training sessions three or four times a week.

Measurements of body weight and waist circumference of the participants were also taken.

Write in the journal eLiferesearchers said 56.8 percent of those following the green Mediterranean diet had a lower brain age than expected at the end of the study.

And they saw that each percent drop in BMI or weight correlated with a nine-month drop in brain age.

Those in this group saw their BMI decrease by 0.76 units, lose an average of 5 lbs (2.31 kg) and 5.39 cm from their waist.

Study author Dr. Gidon Levakov, from the university’s Department of Brain and Cognitive Sciences, said: ‘Our study highlights the importance of a healthy lifestyle, including lower consumption of processed foods, sweets and beverages, for maintaining brain health.

Co-author Professor Galia Avidan said: ‘We were encouraged to find that even a 1 percent weight loss was enough to affect brain health and lead to a 9-month reduction in brain age.’

However, the scientists did not examine whether the decline in brain age affected the participants’ cognition. They noted that the findings are also limited by most of the participants being men and a lack of a control group to compare the findings to.

One million patients, who were at a healthy weight with a body mass index (BMI) of 18 to 25, would cost the NHS an average of £638 each in 2019, the study’s final year. By comparison, severely obese patients with a BMI of 40 and above cost more than double – £1,375 a year. Meanwhile, the NHS spent £979 a year on obese patients with a BMI of 30 to 35, which increased to £1,178 a year for those with a BMI of 35-40

Studies have previously suggested that weight loss, lowering blood pressure and controlling blood sugar reduced brain cell loss.

Research has also linked obesity to declining connectivity within the default mode network – the part of the brain that is active during passive rest.

Obesity is also associated with multiple adverse health consequences.

The latest NHS data shows that 26 per cent of adults in England are obese and a further 38 per cent are overweight but not obese. One third of Americans are overweight, while four in ten are obese.

Obesity rates have been rising for decades, with experts blaming sedentary lifestyles and unhealthy diets.

They are also rising in children, with a quarter of children in shelters in England now considered overweight and one in ten obese.

A landmark study earlier this month also revealed that the UK’s bulging waistline sheds billions of pounds each year from the cramped NHS, spending twice as much on obese patients as on those of a healthy weight.

The cost per patient increases dramatically as people weigh more because they “accumulate obesity-related conditions” such as type 2 diabetes, cancer and heart disease, according to research involving nearly 2.5 million people.