- A new study showed that a Mediterranean diet or MIND resulted in better cognitive health for women.
- The study of 509 twins found that those who followed these diets retained better episodic and visuospatial working memory after 10 years.
- Possible mechanisms by which diets help maintain cognitive health are specific gut bacteria and short-chain fatty acids.
A new study analyzing data from middle-aged women investigates the potential benefits of a Mediterranean diet, or MIND, on cognitive health.
The research included genetically identical (monozygotic) twins and fraternal (dizygotic) twins.
The study finds that among monozygotic twin pairs, the twin with higher adherence to either the Mediterranean diet or MIND maintains slightly stronger episodic and visuospatial working memory.
This observation was significant for twins with a greater Mediterranean adherencediet.
Monozygotic twins both develop from a single egg, or “egg.” Fraternal or “dizygotic” twins are born together but do not come from the same egg. They are sometimes referred to as twins or birth partners. Monozygotic twins are genetically identical. Dizygotic twins share approximately 50% of their genes.
In this study, researchers analyzed data from 509 female twins who were registered in the UK Adult Twin Register between 1992 and 2004. Of this group, 34% were monozygotic and 66% were dizygotic.
The study group included healthy twins with a complete set of baseline data regarding diet – via questionnaires – and cognitive performance. Approximately 10 years later, between 2008 and 2010, the twins underwent new cognitive tests and the participants’ fecal samples were analyzed.
A higher adherence to the MIND diet at baseline was associated with a greater abundance of bacteria Ruminococcaceae and short-chain fatty acids in the chase.
However, this association was not significant after adjustment for dietary fiber intake.
The study is published in the journal
“This study distinguishes itself by focusing on female twins, providing a unique perspective on the interaction between diet and cognitive health,” said Michelle Routhenstein, a registered dietitian who specializes in heart disease at EntirelyNourished, and who was not involved in this. study.
“By taking into account shared genetics and early life experiences, it delves into the potential cognitive advantages associated with Mediterranean and MIND diets, especially as individuals reach middle age,” she added.
Dr. Thomas Holland, of the Department of Internal Medicine, Division of Digestive Diseases and Nutrition at Rush University, also not involved in the study, commented on its importance for Medical News Today.
“This study provides further evidence that our dietary habits in middle age can significantly affect our cognitive health,” he told us. “It goes beyond the assumption that such habits are only useful later in life, emphasizing their importance during middle age.”
He noted that when we think of cognitive development, we often see it as “a trajectory of improvement from childhood through adulthood and middle age, with the expectation of a decline with age.”
More importantly, he said: “This study suggests that we have the potential to increase our cognitive resilience and build cognitive reserve during middle age. These benefits may extend into older age, enabling us to better preserve our cognitive abilities over time.”
The cognitive health benefits reported in this study were less dramatic than are sometimes seen in studies of older people.
This may be because, as Dr. Holland: “It is usually assumed that individuals at this stage are already operating at higher levels of cognitive function, approaching a theoretical ceiling. This dynamic contributes to the diminishing effect seen in this demographic.”
“Episodic memory refers to our ability to draw on personal experiences to learn new information, retain it, and recall it when needed,” explained Dr. Holland.
“Meanwhile,” he said, “visual memory involves the ability to recognize objects and their spatial locations, assimilate this information, and then process and retain specific details about the objects.”
“These cognitive functions are crucial quasi-biomarkers of eventual cognitive health,” noted Routhenstein, “as deficits in them often manifest early in neurodegenerative diseases such as Alzheimer’s, making their preservation indicative of lower risk for cognitive decline.” .
Such cognitive abilities and others together contribute to global cognition.
“While a deficit in one cognitive domain may not necessarily imply a general decline in global cognition,” said Dr. Holland, “may serve as a valuable indicator of cognitive health or trajectory.”
Both the Mediterranean diet and MIND are anti-inflammatory and healthy diets.
The study authors can present an additional piece of data that explains the mechanistic link between these diets and strong cognitive reserve: Ruminococcaceae and short-chain fatty acids.
Routhenstein explained:Ruminococcaceae bacteria in the gut produce short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate through the fermentation of dietary fiber, contributing to gut health and exerting anti-inflammatory effects essential for protecting neuronal function.
“These SCFAs, in turn, play a role in modulating the activity of the immune system by reducing the recruitment of monocytes and neutrophils, thereby exhibiting anti-inflammatory properties.”
– Dr. Thomas Holland, physician scientist
“Additionally,” Routhenstein noted, “SCFAs act as energy substrates for intestinal epithelial cells and can cross the blood-brain barrier, providing energy for brain cells and regulating neurotransmitter levels, potentially enhancing cognitive function. “.
However, experts stressed that people need to prioritize more than just their dietary habits to maintain brain health as they age.
“While diet plays a key role, it is only one component of an overall healthy lifestyle,” said Dr. Holland.
He mentioned the following lifestyle interventions to maintain cognitive health:
- engaging in moderate to vigorous physical activity
- cultivating an active social circle
- participating in mentally stimulating activities (eg, visiting museums or exploring new hobbies)
- prioritizing the quality and quantity of sleep
- implementation of stress reduction techniques