Caffeine Intake and Type 2 Diabetes Risk
Research on the effects of caffeine intake on a person’s risk for type 2 diabetes (T2D) has provided conflicting results, according to a team led by researchers at the Harvard School of Public Health in Boston. The researchers conducted a study to better understand whether caffeinated beverages like coffee and tea help to lower or raise the risk of T2D.
The study, “Caffeinated and caffeine-free beverages and risk of type 2 diabetes,” was published online ahead of print in November 2012. It appears in the American Journal of Clinical Nutrition.
The researchers looked at data on 74,749 women in the Nurses’ Health Study, and 3,059 men from the Health Professionals Follow-Up Study. At baseline, none of the study participants had diabetes, cancer, or any cardiovascular diseases. The study authors measured the association between T2D risk and consumption of the following beverages: caffeinated beverages, caffeine-free beverages, sugar-sweetened beverage (SSBs), and carbonated artificially sweetened beverages (ASBs).
In the 24-year follow-up of the Nurses’ Health Study, the researchers found 7,370 cases of T2D; in the 22-year follow-up in the Health Professionals Follow-Up Study, there were 2,865 T2D cases documented. The researchers found that drinking both caffeinated and caffeine-free SSBs was linked to a higher risk of developing T2D. ASBs that did not contain caffeine were also found to be associated with T2D risk (in the Nurses’ Health Study).
On the other hand, the results also showed an association between drinking both caffeinated and decaffeinated coffee and a lower risk of developing T2D. This lowered risk was seen in caffeinated (but not decaffeinated) tea.
The researchers conclude that their findings demonstrate a positive association between drinking beverages that are sweetened with sugar and risk of type 2 diabetes. However, coffee intake alone was associated with a lowered risk of developing T2D.