How Could a Mediterranean Diet Protect Memory and Brain Health?

• Studies increasingly show a link between diet and physical and mental health.
• Diets rich in plants and whole grains can reduce the risk of several health conditions, improve cognition, and decrease the risk of neurodegenerative diseases, such as dementia.
• Now, a study has shown that the Mediterranean diet, which emphasizes plants, whole grains and healthy fats, is associated with improved memory and learning in young rats.
• The authors suggest that similar dietary changes could have cognitive benefits for children and adolescents.

According to the World Health Organization (WHO)Following a healthy diet throughout life can not only protect against malnutrition, but can also reduce the risk of non-communicable diseases, such as diabetes, heart disease, stroke and cancer.

The WHO advises that a healthy diet includes:

• fruits, vegetables, nuts and whole grains
• less than 10%, and ideally less than 5%, of total energy intake from free sugars, such as those found in honey, syrups, fruit juices, soft drinks and prepared foods ,
• less than 30% of total intake comes from fat, most of which should be unsaturated fats from fish and vegetable oils, rather than animal fats
• less than 5 grams (g) of salt per day.

More and more, studies suggest that a healthy diet may also reduce the risk of cognitive disorders, such as dementia.

THE Mediterranean diet and variations thereof, which emphasize the consumption of fruits, vegetables, whole grains and olive oil, while limiting meat, dairy and ultra-processed foods, can be particularly beneficial for brain health.

There are few studies investigating the cognitive effects of a Mediterranean diet in young people, but Afrom Mexico, showed the academic and cognitive benefits of a Mediterranean-style diet compared to a typical Western diet.

Now, a rat study tested whether such benefits could be due to changes in the gut microbiota resulting from a Mediterranean rather than a Western diet.

The study, published in Gut Microbe Reportssuggests that not only did the Mediterranean diet change the gut microbiota and improve serum lipid levels, but it also improved memory and cognition.

Scott Kaiser, MDsaid a board-certified geriatrician at Providence Saint John’s Health Center in Santa Monica, Calif., who was not involved in this study. Medical news today:

“More and more evidence clearly supports a strong correlation between diet and brain health. Although this study, as well as other related basic studies in this area, are not designed to specifically establish causation, there are many clear causal pathways and plausible biological mechanisms that support the likelihood that various dietary patterns and factors Nutritional health benefits can protect our brain health or accelerate cognitive decline and impact our mental well-being.

At the start of the 20-week study, the rats were 10 weeks old. Studies show that laboratory rats become sexually mature at 6 weeks of age, and as adults, one month is equivalent to approximately 3 years of human life, so the developmental stage of the rats in this study is equivalent to people aged approximately 8 at 20 years old.

Initially, the researchers randomly assigned the 20 rats to either a Western diet, containing 15% protein, 50% carbohydrates and 35% fat (mostly butter), or a Mediterranean diet, containing 12% butter. protein, 45% carbohydrates and 43% fat (mainly olive oil).

The Mediterranean diet contained more than twice as much fiber (63.4 grams per kilogram (g/kg)) as the Western diet (27.9 g/kg).

During the study, researchers monitored the rats’ body weight and food consumption to ensure that energy intake was similar in the 2 groups. They also collected fecal samples for analysis at the start of the study and after 14 weeks on the diet, when the rats began a series of behavioral tests.

They detected widespread changes in the gut microbiota of rats on the Mediterranean diet. These rats showed an increase in four types of bacteria and a decrease in five other types compared to those on the Western diet.

In behavioral tests, Mediterranean diet rats showed better cognitive flexibility and improved aspects of spatial reference and working memory. These improvements were correlated with higher levels of Candidate saccharimonas and lower levels of Bifidobacteria in their intestinal microbiota.

The researchers suggest that this change in the microbiota could be responsible for the improvement in the cognitive functions of rats fed the Mediterranean diet.

Kelsey Costa, MS, RDNregistered dietitian nutritionist and founder of Dietitian Insights, who was not involved in this study, agreed with this hypothesis, saying MNT that “this study adds to the growing body of evidence for a potential link between altered microbiota and improved memory function.”

“The gut-brain axis enables bidirectional communication between the gut and the brain, with the gut microbiome potentially influencing cognitive functions such as attention, perception and memory. The gut microbiota modulated by diet could impact cognition, notably by disrupting immune function,” she explained.

Most research on the relationship between the microbiota and cognitive function has focused on neurodegenerative diseases, like dementiabut this study suggests that modifying the microbiota by improving diet could also improve cognitive functions in adolescence.

“Although causal evidence has not been established, observational research has suggested a link between diet quality and cognitive performance in children and adolescents.”

– Kelsey Costa, MS, RDN

The authors emphasize that further research is needed to determine whether there is a causal relationship between diet quality and cognition.

Costa agreed, noting that: “Overall, encouraging a healthy diet like the Mediterranean diet from an early age may have long-term benefits for cognitive function in children and adolescents. But more research is needed to fully understand the mechanisms and apply these findings to human populations.

Whether or not the Mediterranean diet can improve cognition, it is generally accepted that following this type of diet has health benefits.

Molly Rapozo, RDNRegistered dietitian nutritionist and senior nutrition and health educator at the Pacific Neuroscience Institute in Santa Monica, California, also not involved in this study, shared the following dietary tips for people concerned about brain health:

“We can modify our diet to maintain and improve brain health by including vegetables, fruits, starchy foods like whole grains, legumes and potatoes; as well as lean proteins, fatty fish and plant-based fats such as nuts, seeds, avocado, olives and olive oil. Eat less highly processed snack foods, fatty meats including bacon and sausage, sugar and other refined carbohydrates.