Low-fat dietary pattern does reduce dementia mortality in postmenopausal women

For postmenopausal women, following a low-fat dietary pattern does not appear to favourably influence dementia mortality, according to a study.

Researchers used data from the Women’s Health Initiative (WHI) Dietary Modification (DM) randomized trial, which demonstrated that the dietary intervention substantially reduced breast cancer mortality in the overall population and decreased possible cognitive impairment based on Modified Mini-State Examination (3MSE) scores in a subgroup of women aged ≥65 years.

The present analysis included 48,835 postmenopausal women aged 50–79 years who participated in the WHI DM trial. These participants had dietary fat intake of ≥32 percent of energy and anticipated ≥3-year survival.

The participants were randomly allocated to a low-fat dietary pattern intervention with goals to reduce fat intake and increase fruit, vegetable, and grain intake (n=19,541) or a usual diet comparison (n=29,294). Dementia mortality was assessed after a median of 8.5-year dietary intervention and 20-year cumulative follow-up.

Relative to usual diet, low-fat dietary intervention had a null effect on dementia mortality (hazard ratio [HR], 0.94, 95 percent confidence interval [CI], 0.85–1.05), with similar findings for Alzheimer (HR, 1.00, 95 percent CI, 0.85–1.17) and non-Alzheimer dementia mortality (HR, 0.90, 95 percent CI, 0.77–1.05).

In subgroup analyses, a trend for lower dementia mortality with low-fat dietary intervention vs usual diet was observed in younger women (50–59 years: HR, 0.73; 60–69 years: HR, 0.85; 70–79 years: HR, 1.06; p=0.03 for trend).