A recent study examines the possible advantages of a Mediterranean or MIND diet on cognitive health using data from middle-aged female participants.
Both fraternal (dizygotic) and genetically identical (monozygotic) twins were studied.
According to the study, in pairs of monozygotic twins, the twin that adhered more strictly to the MIND or Mediterranean diets was able to maintain slightly better episodic and visuospatial working memory.
This finding was noteworthy in the case of the twins who followed the Mediterranean diet more closely.
A single egg, or “ovum,” gives rise to both monozygotic twins. “Dizygotic,” or fraternal, twins are born together but do not share an egg. They are also known as birth partners or co-twins. Genetically, monozygotic twins are identical. About half of the genes in dizygotic twins are shared.
Data from 509 female twins who registered with the UK Adult Twin Registry between 1992 and 2004 were examined by the researchers for this study. 34% and 66%, respectively, of this group were monozygotic.
The research sample included of healthy twins who provided a comprehensive set of baseline information on their nutrition and cognitive abilities through questionnaires. Between 2008 and 2010, almost ten years later, twins underwent fresh cognitive testing, and fecal samples from participants were examined.
Ruminococcaceae bacteria and short-chain fatty acids were found in larger concentrations in subjects who adhered to the MIND diet more closely at baseline and follow-up.
When dietary fiber intake was taken into account, this link did not remain significant.
The significance of maintaining a nutritious diet in middle age
Michelle Routhenstein, a registered dietitian nutritionist at EntirelyNourished with a focus on heart disease, said, “This study sets itself apart by honing in on female twins, offering a unique perspective on the interplay between diet and cognitive health.” Routhenstein was not involved in this study.
“By factoring in shared genetics and early life experiences, it delves deeper into the potential cognitive advantages associated with Mediterranean and MIND diets, particularly as individuals reach midlife,” she added.
Additionally unrelated to the study was Dr. Thomas Holland of Rush University’s Department of Internal Medicine, Division of Digestive Diseases and Nutrition.
He informed us, “This study offers more proof that the foods we eat in our middle years can have a major impact on our cognitive health.” “It emphasizes their relevance during midlife, going beyond the assumption that such habits are only beneficial later in life.”
According to him, cognitive growth is commonly perceived as “a trajectory of improvement from childhood through adulthood and into midlife, with the expectation of some decline as we age.”
He made a crucial statement: “This study indicates that we have the capacity to improve our cognitive reserve and resilience in midlife. These advantages might last into old life, helping us to more effectively preserve our mental capacities as we age.
The study’s claimed improvements in cognitive health were not as significant as those occasionally observed in research with older adults.
This may be because, as Dr. Holland suggested: “It’s commonly assumed that individuals in this stage are already operating at higher levels of cognitive function, approaching a theoretical ceiling. This dynamic contributes to the diminished observable effect in this demographic.”
What do visuospatial and episodic memory mean?
Tests of multiple cognitive functions are typically used to assess cognitive healthTrusted Source, of which episodic and visuospatial memory are just two.
Dr. Holland defined episodic memory as “our ability to use personal experiences for learning new information, retaining it, and recalling it when necessary.”
“In the meantime,” he explained, “visuospatial memory is the capacity to identify objects and their spatial locations, assimilate this knowledge, and then process and remember particular details about the objects.”
According to Routhenstein, “deficits in these cognitive functions often manifest early in neurodegenerative diseases like Alzheimer’s, making their preservation indicative of lower risk for cognitive decline.” As a result, these cognitive skills are important quasi-biomarkers of eventual cognitive health.
Global cognition is influenced by a variety of cognitive capacities, including these.
According to Dr. Holland, “a deficit in one cognitive domain can be a useful indicator of cognitive health or trajectory, even though it may not always indicate a decline in overall global cognition.”
How nutrition may affect the health of the brain
The MIND and Mediterranean diets are both anti-inflammatory, healthful diets.
Ruminococcaceae and short-chain fatty acids may offer another hint as to the mechanism behind the association between these diets and robust cognitive reserve, according to the study’s authors.
As per Routhenstein’s explanation, “Ruminococcaceae bacteria in the gut ferment dietary fiber to produce short-chain fatty acids (SCFAs) like acetate, propionate, and butyrate, which are important for gut health and neuronal function protection.”
“Additionally,” Routhenstein noted, “SCFAs act as energy substrates for gut epithelial cells and may cross the blood-brain barrier, providing energy to brain cells and modulating neurotransmitter levels, potentially enhancing cognitive function.”
However, the experts noted that in order to preserve brain function as one ages, one should give consideration to more than one’s eating habits.
“Diet is important, but it’s only one part of a whole healthy lifestyle,” Dr. Holland stated.
In order to maintain cognitive health, he mentioned the following lifestyle interventions:
- putting in a moderate to intense amount of exercise
- fostering a social network that is active
- engaging in brain stimulating pursuits (such as going to museums or taking up new hobbies)
- putting both quantity and quality of sleep first
- putting stress-reduction strategies into practice