Background
A recent systematic review found a statistically significant positive association between the intake of sugar sweetened beverages and the risk of type 2 diabetes in observational studies. To-date, there are no systematic reviews investigating the relationship between diet soft drinks, water (i.e., non-calorific beverages) and the risk of type 2 diabetes.
Aim
To evaluate the association between diet soft drinks, water and the risk of type 2 diabetes in observational studies.
Methods
Two independent investigators searched PubMed, ScienceDirect and Cochrane library databases up until May 2013 using the search terms diet beverages/soda/drink, non-nutritively sweetened/artificially sweetened beverages, water and diabetes. Bibliographies of all retrieved studies were also independently searched, and experts in the field contacted.
Results
From 26 relevant retrieved reports, 7 articles (1-7) covering 10 studies were identified. From 5-24 years of follow-up, a total of 40,065 incident cases of type 2 diabetes were identified out of 540,343 participants. In models adjusted for all known diabetes risk factors, including energy and body mass index, 4 out of 10 studies found a positive, statistically significant association between diet soft drinks/water and risk of type 2 diabetes, 1 study had a borderline significant positive association (P=0.06), 5 studies had non-significant positive associations.
Conclusion
The association between diet soft drinks, water and the risk of type 2 diabetes may be positive, although at least half of the published studies are not statistically significant. A meta-analysis of these observational studies is warranted to quantify the association and determine overall statistical significance.