Mediterranean diet linked to improved memory via changes in gut bacteria

A new study from Tulane University suggests that the brain-boosting benefits of the Mediterranean diet may work by changing the balance of bacteria in the gut.

In a study published in Gut microbe reportsResearchers from Tulane University School of Medicine found that subjects who followed a Mediterranean diet developed markedly different gut bacteria patterns than those who followed a typical Western diet. These bacterial changes correlated with better memory and cognitive performance.

“We know that what we eat affects brain function, but this study explores how that might happen,” said lead author Rebecca Solch-Ottaiano, Ph.D., research instructor in neurology at Tulane’s Clinical Neuroscience Research Center. “Our findings suggest that dietary choices can influence cognitive performance by reshaping the gut microbiome.”

The study found that rats fed a Mediterranean diet rich in olive oil, fish and fiber for 14 weeks showed an increase in four beneficial types of gut bacteria and a decrease in five others, compared to rats fed a Western diet high in saturated fats. ate. These bacterial changes were linked to improved performance on maze challenges designed to test memory and learning.

Specifically, higher levels of bacteria, such as Candidatus Saccharimonas, were associated with better cognitive performance, while increased levels of other bacteria, such as Bifidobacterium, correlated with poorer memory function.

The Mediterranean diet group also showed better cognitive flexibility (the ability to adapt to new information) and improved working memory compared to the Western diet group. They maintained lower levels of the ‘bad’ LDL cholesterol.

This study is the first to assess the effects of the Mediterranean on microbiota and cognitive function outcomes compared to the Western diet in a rodent model. The researchers used young rats roughly equivalent in age to 18-year-old humans to model the effects of diet during a critical developmental period. The diets were based on human consumption and used ingredients that reflected the complexity of human diets. The Mediterranean diet (MeDi) showed clear benefits for cognitive flexibility, memory and gut health, suggesting possible parallels in young adults whose brains and bodies are still maturing.

“Our findings suggest that the Mediterranean diet or its biological effects could be harnessed to improve school performance in adolescents or work performance in young adults,” said corresponding author Dr. Demetrius M. Maraganore, Herbert J. Harvey, Jr. chair of Neurosciences. . “Although these findings are based on animal models, they mirror human studies linking the Mediterranean diet to improved memory and reduced risk of dementia.”

The researchers emphasize that larger human studies are needed to confirm these effects and better understand the complex relationship between diet, gut bacteria and brain function in young people.

For those interested in following a Mediterranean diet, the key components are:

• Olive oil as the main source of fat
• Abundant vegetables, fruits and whole grains
• Fish and lean proteins
• Limit red meat and saturated fats
• High fiber intake from various plant sources

Other Tulane co-authors of the study include Elizabeth B. Engler-Chiurazzi, Colin Harper, Savannah Wasson, Sharon Ogbonna, Blake Ouvrier, Hanyun Wang, Madison Prats, Katherine McDonald, Ifechukwude J. Biose, Lori A. Rowe, MaryJane Jones, Chad Steele and Gregory Bix.