Adolescent dairy product consumption and risk of type 2 diabetes in middle-aged women

Abstract

Background: Type 2 diabetes (T2D) prevention has generally focused on the identification of risk factors in adulthood. Dairy product consumption in adults has been associated with a lower risk of T2D.

Objective: The objective was to evaluate the relation between dairy product consumption during adolescence and risk of T2D in adulthood.

Design: We examined the incidence of T2D in relation to high school dairy product consumption within the Nurses' Health Study II cohort. A total of 37,038 women who completed a food-frequency questionnaire about their diet during high school were followed from the time of return of the questionnaire in 1998-2005. Cox proportional hazards regression was used to estimate RRs and 95% CIs.

Results: Compared with women in the lowest quintile of high school dairy product intake, those in the highest quintile (2 servings/d) had a 38% lower risk of T2D (RR: 0.62; 95% CI: 0.47, 0.83; P-trend = 0.0006), after adjustment for high school risk factors. After adjustment for adult risk factors, the association persisted (RR: 0.73; 95% CI: 0.54, 0.97; P-trend = 0.02) but was attenuated after adjustment for adult dairy product consumption. In a multivariate joint comparison of dairy product consumption by adults and high school adolescents, compared with women with consistently low intakes, those with consistently high intakes had the lowest risk of T2D (RR: 0.57; 95% CI: 0.39, 0.82).

Conclusions: Our data suggest that higher dairy product intake during adolescence is associated with a lower risk of T2D. Some of the benefits of dairy product intake during high school may be due to the persistence of the consumption pattern during adulthood.

FIGURE 1.

Joint analysis between current dairy product intake and dairy product intake during high school in relation to type 2 diabetes (T2D) risk. Tertiles (low, medium, or high) of dairy product intake in high school and adulthood were cross-classified into a single categorical variable and evaluated for risk of T2D by using the low-low category as the reference (Ref). High current dairy product intakes are depicted by dark gray bars, medium intakes by light gray bars, and low intakes by white bars. Models were adjusted for age, current BMI, total energy intake, family history of diabetes, smoking status, physical activity, alcohol use, oral contraceptive use, hormone replacement therapy, polyunsaturated:saturated fat ratio, glycemic load, and intakes of cereal fiber, trans fat, processed meat, carbonated soft drinks, fruit drinks, and coffee. RRs (95% CI) for current intake–intake during high school: Low-Low (reference), 1.00; Medium-Low, 1.11 (0.81, 1.52); High-Low, 0.94 (0.63, 1.41); Low-Medium, 1.05 (0.76, 1.46); Medium-Medium, 1.06 (0.78, 1.45); High-Medium, 0.84 (0.59, 1.21); Low-High, 1.05 (0.72, 1.52); Medium-High, 1.12 (0.81, 1.55); and High-High, 0.57 (0.39, 0.82). Median current dairy product intake (servings/1000 kcal): Low = 0.76, Medium = 1.25, and High = 1.89. Median dairy product intake during high school (servings/1000 kcal): Low = 0.65; Medium = 1.16; and High = 1.78. P-interaction = 0.049 based on the cross-product of median values of tertiles. Serv, servings.