Alignment of dietary patterns with the Dietary Guidelines for Americans 2015-2020 and risk of all-cause and cause-specific mortality in the Women’s Health Initiative Observational Study

Poor diet quality is a leading risk factor for death in the United States (U.S.). We examined the association between Healthy Eating Index-2015 (HEI-2015) scores and death from all-causes, cardiovascular disease (CVD), cancer, Alzheimer’s Disease and Dementia not otherwise specified (NOS) among postmenopausal women in the Women’s Health Initiative Observational Study (1993-2017). This analysis included 59,388 participants who completed a food frequency questionnaire and were free of cancer, CVD and diabetes at enrollment. Stratified Cox proportional hazards models were fit using person-years from enrollment as the underlying time metric. We estimated multivariable adjusted hazard ratios and 95% confidence intervals for risk of death associated with HEI-2015 quintiles, with higher scores reflecting more optimal diet quality. Over a median of 18.2 years, 9,679 total deaths 3,303 cancer deaths, 2,362 CVD deaths, and 488 deaths from Alzheimer’s Disease and Dementia NOS occurred. Compared to those with lower scores, women with higher HEI-2015 scores had an 18% lower risk of all-cause mortality and 21% lower risk of cancer mortality. HEI-2015 scores were not associated with mortality from CVD, Alzheimer’s Disease and dementia NOS. Consuming a diet aligned with 2015-2020 U.S. Dietary Guidelines may have beneficial impacts for preventing death from cancer and overall.