(Ivanhoe Newswire) -- Individuals who drink coffee or tea, whether it is
caffeinated or decaf, appear to have a substantially lower risk of developing
type 2 diabetes.
By the year 2025, approximately 380 million individuals worldwide will be
affected by type 2 diabetes. "Despite considerable research attention, the role
of specific dietary and lifestyle factors remains uncertain, although obesity
and physical inactivity have consistently been reported to raise the risk of
diabetes mellitus," the authors were quoted as saying.
Rachel Huxley, D.Phil, of The George Institute for International Health,
University of Sydney, Australia, and colleagues looked at 18 studies, involving
457,922 participants, which assessed the association between coffee consumption
and diabetes risk. The studies were published between 1966 and 2009. Six of the
studies included information about decaffeinated coffee, and seven studies also
reported on tea consumption.
When the authors combined and analyzed the data, they found that 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
addition, 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.
"That the apparent protective effect of tea and coffee consumption appears to be
independent of a number of potential confounding variables raises the
possibility of direct biological effects," according to the authors. The authors
noted that the association is unlikely to be solely related to caffeine, but
that other compounds in coffee and tea—including magnesium, antioxidants known
as lignans or chlorogenic acids—may be involved.
"If such beneficial effects were observed in interventional trials to be real,
the implications for the millions of individuals who have diabetes mellitus, or
who are at future risk of developing it, would be substantial," they concluded.
"For example, the identification of the active components of these beverages
would open up new therapeutic pathways for the primary prevention of diabetes
mellitus. It could also be envisaged that we will advise our patients most at
risk for diabetes mellitus to increase their consumption of tea and coffee in
addition to increasing their levels of physical activity and weight loss."
SOURCE: Archives of Internal Medicine, December 14/28, 2009
