Abstract 20: Dairy Consumption in Young Adulthood and Risk of Coronary Artery Calcification Later in Life

Introduction: The relationship of dairy with cardiovascular disease (CVD) remains controversial. Meta-analyses have shown a modest, protective association of dairy, and other recent evidence has indicated that whole-fat dairy may not be inferior to low-fat dairy, despite concerns about its saturated fat content. Hypothesis: Intakes of total, whole-fat and low-fat dairy during young adulthood are inversely associated with risk of incident coronary artery calcification (CAC), a subclinical marker of atherosclerosis and predictor of future CVD events. Methods: In 3,110 young adult participants of the Coronary Artery Risk Development in Young Adults (CARDIA) study, dairy consumption was assessed via a validated diet history. Intake was averaged between baseline (1985-86) and year 7 exams. The first occurrence of CAC score >0 among years 15, 20 and 25 was identified in 904 participants; the remainder were censored at the last available of these exams. Cox proportional hazards regression was used to estimate associations of CAC incidence with each of total, low-fat, and whole-fat dairy. Results: Median daily consumption of total dairy was 1.2 servings in quartile 1 and 5.4 servings in quartile 4. After adjustment for energy intake and other variables, associations of total and low-fat dairy with CAC were null. However, a monotonic trend was observed across quartiles of whole-fat dairy intake, where individuals in the highest quartile had a lower risk of CAC (hazard ratio: 0.74 (0.60, 0.93)) compared to those in the lowest quartile. Conclusions: Whole-fat dairy showed an inverse association with CAC 15 to 25 years later. Possible explanations for this finding include potentially cardioprotective effects of the unique profile of fatty acids or other fat-soluble constituents found in dairy products, as well as the displacement of foods and beverages in the diet. These results challenge dietary guidelines that recommend replacing whole-fat dairy with low-fat alternatives.