CHICAGO–Individuals who drink more coffee (regular or decaffeinated) or tea appear to have a lower risk of developing type 2 diabetes, according to an analysis of previous studies reported in the December issue of Archives of Internal Medicine (2009;1699(22):2053-2063).
Researchers identified 18 studies involving 457,922 participants and assessed the association between coffee consumption and diabetes risk published between 1966 and 2009. Six studies involving 225,516 individuals also included information about decaffeinated coffee, whereas seven studies with 286,701 participants reported on tea consumption.
When the authors combined and analyzed the data, they found each additional cup of coffee consumed in a day was associated with a 7-percent reduction in the excess risk of diabetes. Individuals who drank three to four cups per day had an approximately 25-percent lower risk than those who drank between zero and two cups per day.
In the studies that assessed decaffeinated coffee consumption, those who drank more than three to four cups per day had about a one-third lower risk of diabetes than those who drank none. Those who drank more than three to four cups of tea had a one-fifth lower risk than those who drank no tea.
Because of the association between decaffeinated coffee and diabetes risk, the association is unlikely to be solely related to caffeine. Other compounds in coffee and tea—including magnesium, antioxidants known as lignans or chlorogenic acids—may be involved, the authors note.
