Background/objectives: Dietary fat intake may influence the rate of cognitive change among those at high risk due to vascular disease or risk factors.
Subjects/methods: Women's Antioxidant Cardiovascular Study began in 1995-1996 as a randomized trial of antioxidants and B vitamin supplementation for secondary prevention in women with cardiovascular disease or ≥3 coronary risk factors. From 1998-1999, eligible participants aged ≥65 years were administered a telephone cognitive battery including five tests of general cognition, memory and category fluency (n=2551). Tests were administered four times over 5.4 years. The primary outcome was a global composite score averaging z-scores of all tests. Multivariable generalized linear models for repeated measures were used to evaluate the difference in cognitive decline rates across tertiles of total fat and various types of fat.
Results: Total fat intake or different types of fat were not related to cognitive decline. However, older age significantly modified the association: among the oldest participants, higher intakes of mono- and polyunsaturated fat were inversely related to cognitive decline (P-interaction: 0.06 and 0.04, respectively), and the rate differences between the highest and lowest tertiles were cognitively equivalent to the rate differences observed with being 4-6 years younger.
Conclusions: In women at high risk of cognitive decline due to vascular disease or risk factors, dietary fat intake was not associated with 5-year cognitive change. However, a possible protective relation of unsaturated fats with cognitive decline in the oldest women warrants further study.