Drinking Coffee and Tea May Cut Diabetes Risk
That afternoon cup of coffee may do more than give an energy boost—it could also reduce the risk of developing type 2 diabetes. A new meta-analysis by Rachel Huxley, MD, of the George Institute for International Health, University of Sydney, Australia, and a team of international researchers, suggests that drinking 3 to 4 cups of regular coffee per day can cut diabetes risk by up to 25%. Published December 14, 2009, online in the
Archives of Internal Medicine
, the review also examined data on decaffeinated coffee and tea.
The authors found studies conducted between 1966 and July 2009 that explored a relationship between consumption of coffee or tea and diabetes. Huxley and her colleagues found 18 studies that reported on coffee consumption and diabetes, involving 457,992 participants. 6 of the studies also included information about 225,516 decaffeinated coffee drinkers, and 7 of the studies had data for 286,701 tea drinkers.
The review suggested that every cup of coffee consumed reduces the risk of developing type 2 diabetes by 7%. Participants who drank 3 to 4 cups of coffee per day had about a 25% reduction in risk for developing diabetes, compared with those who do not drink coffee or those who drink ≤ 2 cups per day. Decaffeinated coffee and tea seemed to have a similar effect, but Huxley and her colleagues noted that there was not enough data in the collective studies to make a per—cup correlation.
Huxley noted that proper diet and exercise are currently the best known ways to reduce the risk of developing type 2 diabetes. These initial findings suggest, however, that coffee and tea contain compounds, such as magnesium, lignans, and chlorogenic acids, that may have an effect on blood sugar regulation. The isolation of the key ingredients that reduce the risk of diabetes could have an impact on future treatment of the disease.
Although the combined studies examined the habits and risk levels of almost half a million participants, the authors contend that “owing to the presence of small-study bias, our results may represent an overestimate of the true magnitude of the association.” They recommend that randomized trials be conducted to confirm their findings.
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