The Mediterranean diet incorporates the traditional cuisine of countries bordering the Mediterranean Sea. It is typically high in vegetables, fruits, whole grains, beans, nuts and seeds, and olive oil. In the 1960s it was observed that coronary heart disease caused fewer deaths in Mediterranean countries like Greece and Italy than in the U.S. and northern Europe. Later on, the Mediterranean diet was found to be associated with reduced factors for cardiovascular disease. It is one of the healthy eating plans recommended by the Dietary Guidelines for Americans to promote health and prevent chronic disease. The diet is recognized by the World Health Organization as a healthy and sustainable dietary pattern and as an intangible cultural asset by the United Nations Educational, Scientific and Cultural Organization.
In the latest in a series of reports on the Bezafibrate Infarction Prevention (BIP) cohort, a recent paper in the journal Nutritional Neuroscience found that adherence to the Mediterranean diet predicts cognitive decline two decades later in men with cardiovascular disease. Participants were 200 men (mean age at baseline 57.3 ± 6.3 years) with stable coronary artery disease in a multicenter placebo-controlled randomized clinical trial who completed computerized cognitive assessment [NeuroTrax] 15 and 20 years after baseline. Based on 4-day food diaries, participants with poor adherence to the Mediterranean diet had poorer cognitive function and greater decline in overall cognitive function and visual spatial processing two decades later. Excluding those with interim stroke and dementia, poor adherence was associated with greater decline in overall cognitive function and executive function. Analyses adjusted for a host of variables: education, birth place, energy intake (kcal/day), height, smoking, body mass index, physical activity, New York Heart Association classification, history of hypertension, past myocardial infarction, C-reactive protein (CRP), insulin resistance, and diastolic blood pressure.
The new findings suggest that the Mediterranean diet may decrease existing vascular burden or prevent additional vascular injury, which may lead to improved cognitive performance and reduced decline. Alternatively, the results may be explained by other mechanisms including prevention of amyloid beta accumulation, tau hyperphosphorylation, oxidative stress, and inflammation. Referring to NeuroTrax, the authors note that “the use of a validated computerized assessment tool to quantify cognitive function globally and in specific domains” is a distinct strength of the study. Critically, the study may lay the groundwork for future intervention studies to reduce of cognitive decline in men with a high vascular burden.
Lutski, M., Weinstein, G., Ben-Zvi, S., Goldbourt, U., and Tanne, D. (2020). Adherence to Mediterranean diet and subsequent cognitive decline in men with cardiovascular disease. Nutritional Neuroscience. PMID: 31965911