There is no shortage of observational evidence supporting the relationship between dairy intake, red meat intake, and risk of developing type-2 diabetes. In an exhaustive review of all systematic reviews and meta-analyses published from 1950 to 2013, pooling the results of 29 articles examining the link between common foods groups and risk of developing type-2 diabetes (T2D) revealed dairy to be one of the most protective food groups second only to coffee and nuts. Conversely, red and processed meats were the most detrimental after sweetened beverage intake.
Since this paper’s publication, a recent review of ten randomized controlled trials in which only dairy intake was altered found that four showed a positive effect on insulin sensitivity, five showed no effect, and one showed a negative effect. Conversely, a meta-analysis of three U.S. cohorts with 194,491 persons and 3,984,203 person-years of follow-up found only yogurt consumption to be associated with a lower risk of T2D. Interestingly, the intake of dairy fat is also associated with glucose tolerance and incident of T2D.
