The study published by Jordi Salas-Salvado’s team from Universitat Rovira i Virgili, in Spain, confirms the existing results and namely those of the two most recent studies in that field of research. In US, Chen et al. showed that yogurt consumption was associated with a risk reduction of type 2 Diabetes of 17% and in UK, O’Connor et al showed that yogurt consumption was associated with a larger risk reduction of type 2 diabetes of 28%.
A specific effect of yogurt
The specificity of the renowned PREDIMED used in this Spanish study enables authors to explore different approaches in terms of dairy consumption habits during the 4 years of follow-up. The results demonstrated that the risk reduction was maintained in both low-fat (32%) and whole fat (34%) yogurt when they were examined separately. The increased consumption of total low-fat dairy and total yogurt during the follow-up was also inversely associated with type 2 diabetes risk. Moreover, substituting 1 serving/day of a combination of biscuits/chocolate or whole grain biscuits/homemade pastries for 1 serving/day of yogurt was associated with a 40 and 45% reduction risk, respectively.
More yogurt in Spain
To explain this huge result for yogurt (-40% reduction risk) as compared to previous surveys, the authors hypothesized an association with the specificity of the target population,
highly predisposed to develop type 2 diabetes in a short period of time. Another explanation could be the higher level of yogurt consumption in Spain, as compared to US or UK surveys. Actually, a large distribution of yogurt may give more chance to demonstrate associations between high and low consumers of yogurt.
Multiple mechanisms might mediate the relationship between dairy consumption, yogurt and type 2 diabetes risk. Some components of dairy products as calcium, magnesium, potassium, and vitamin-D have been attributed with having a potential benefit on type 2 diabetes. Other postulated mechanisms include the satiating effect of some dairy proteins and fats, which may help in maintaining a lower energy intake and decreasing weight and obesity risk, an important mediator in type 2 diabetes development. Another potential mechanism is that some dairy proteins are also known to be insulinotropic, contributing to the reduction in type 2 diabetes risk. Furthermore, it should be taken into account that the beneficial metabolic effects on health of fermented dairy, and particularly yogurt, could be explained by the live microorganisms they contain.
A signature of healthy lifestyle
In addition to the direct effects of dairy products, we cannot ignore displacement effects, as individuals who consumed higher amounts of dairy also consumed higher amounts of other foods, such as fruit, vegetables, and lower amounts of total meat, fish, nuts, and alcohol, which might also have an impact on associations observed.
These recent results confirm the value of working on metabolic diseases and the needs to identify the mechanisms of actions that are specific to yogurt.