Although ultimately inevitable, cognitive decline can be accelerated or delayed by a number of different factors.
Infection, exposure to neurotoxins, and disease are the primary aggravators in this respect just as diet is our best shot at preventing cognitive disturbances for as long as possible.
According to a new study published in the journal Alzheimer’s and Dementia, a regimen rich with vegetables, fruits, legumes, fish, olive oil, and nuts dramatically reduces one’s risk of developing neurodegenerative diseases later in life.
“Observational analyses of participants enrolled in two randomized trials of nutritional supplements for age‐related macular degeneration: Age‐Related Eye Disease Study (AREDS) and AREDS2,” the authors write of their methods in the new paper. “Closer Mediterranean diet adherence was associated with a lower risk of cognitive impairment but not slower decline in cognitive function.”
Adherence to a Mediterranean diet and cognitive function in Age‐Related Disease
Preceding literature has already established a robust relationship between nutritional supplementation and age-related degeneration.
The peoples of the Blue Zones tend to live much longer than western populations in addition to experiencing far fewer comorbidities.
To get a better idea of the specific mechanisms at play, the authors of the new paper analyzed two previously conducted clinical trials sponsored by the National Eye Institute. The first took place between 1992 and 1998, while the second spanned the years between 2006 and 2008. Collectively, 7,756 men and women were involved in the two cohort studies.
Researchers devised a questionnaire to determine the dietary and lifestyle habits of each of the participants before administering a standardized test to gauge their cognitive health.
Consistently, individuals who adhered the closest to the Mediterranean diet enjoyed the highest cognitive function throughout the observational study’s 10-year window.
Strict adherence to the Mediterranean diet was specifically defined as habitual consumption of whole fruits, vegetables, whole grains, nuts, legumes, fish and olive oil, as well as reduced amounts of red meat and alcohol.
Fish and vegetables appeared to have the biggest impact on outcomes. Routine fish intake was concurrently associated with higher rates of cognitive functioning and the lowest rate of decline over time.
“Scientists aren’t sure why the Mediterranean diet might help the brain,” explains the National Institute of Aging (NIA) on its website. “This primarily plant-based diet has been shown to improve cardiovascular health, which may, in turn, reduce dementia risk. In contrast, the typical Western diet increases cardiovascular disease risk, possibly contributing to faster brain aging.”
“In addition, this diet might increase specific nutrients that may protect the brain through anti-inflammatory and antioxidant properties,” the Institute concludes.
The study intimated promising finds even if its methods were not without limitations.
The two studies that inspired the newest meta-analysis were in part based on self-reporting. This means that there could be confounding factors influencing outcomes—be they positive or negative.
For instance, it stands to reason that those who habitually eat healthy likely to receive physical activity with enough regularity to sustain their well-being. These individuals might also abstain from substances that carry punitive effects on the biological systems observed. We can then assume that the opposite is true. Lifestyle, education, gender and many other phenotypes were not accounted for enough to know the extent to which they impact the study’s conclusion.
However, the benefits of undertaking the Mediterranean diet were consistent among populations with the ApoE gene which has been studied to increase one’s risk of late-onset Alzheimer’s disease.
It should be noted that participants with ApoE did tend to receive lower median scores for cognitive function than those without the gene in addition to exhibiting cognitive decline with greater frequency.