Changes in intake of dairy product subgroups and risk of type 2 diabetes: modelling specified food substitutions in the Danish Diet, Cancer and Health cohort

Abstract

AbstractWe investigated the association between an increased intake of one dairy product subgroup at the expense of another within a 5-year period and the subsequent 10-year risk of developing type 2 diabetes. Effect modification by the initial level of the dairy product intake was also examined. The cohort included 39,438 men and women with two measurements of diet assessed using food frequency questionnaires (FFQ) administered in 1993-1997 and 1999-2003. Dairy products were skimmed milk, semi-skimmed milk, whole-fat milk, buttermilk, low-fat yogurt, whole-fat yogurt, cheese and butter. Type 2 diabetes cases were ascertained from the Danish National Diabetes Register. The pseudo-observation method was used to calculate risk differences (RD) with 95% confidence intervals (CI). Among participants aged 56-59 years at hand-in of the follow-up FFQ, increased intake of whole-fat yogurt in place of skimmed, semi-skimmed or whole-fat milk was associated with a reduced risk (RD% [95% CI]: −0.8% [−1.3, −0.2]; −0.6% [−1,1, −0.1]; −0.7 [−1.2, −0.1]; per 50g/d, respectively). Among participants aged 60-64 and 65-72, substitution of skimmed milk for semi-skimmed milk was associated with an increased risk of type 2 diabetes (0.5% [0.2, 0.7]; 0.4% [0.1, 0.7]; per 50g/d, respectively). No effect modification by the initial intake of milk products was observed. Our results suggest that substitution of whole-fat yogurt for milk among those aged 56-59 decreases the risk of type 2 diabetes and substitution of skimmed milk for semi-skimmed milk was associated with an increased risk of type 2 diabetes among those aged 60-64 and 65-72, regardless of the initial intake level.