Hypothetical 22-Year Intervention With DASH Diet Lowered Risk of Heart Failure in a General Population.

We used design principles of target trial methodology to emulate the effect of sustained adherence to the Dietary Approach to Stop Hypertension (DASH) diet on the 22-year risk of heart failure. Women and men aged 45-83 years without previous heart failure who answered questionnaires in 1997 from the Swedish Mammography Cohort and the Cohort of Swedish Men were eligible. Follow-up questionnaires were sent in 2008-2009. Incidence of heart failure was ascertained using the Swedish Patient Register updated until 31 December 2019. The parametric g-formula was used to estimate the 22-year risk of heart failure under sustained adherence to a population-adapted DASH diet compared to no intervention. Intakes before 1997 for pre-baseline adjustment was only available in women. In total, 31,238 women and 34,939 men were eligible. The 22-year risk of heart failure was 14.5% with long-term adherence to the DASH diet compared with 15.2% with no intervention (risk difference -0.7%, 95% confidence interval -1.6, 0.0%) in women and correspondingly in men 15.3% vs. 16.2% (risk difference -0.9%, 95% confidence interval -1.6, -0.2%). Our hypothetical intervention suggests that sustained adherence to the population-adapted DASH diet may reduce risk of heart failure in middle-aged and elderly Swedish women and men.