Regular Coffee, Decaf and Tea All Associated With
Reduced Risk of Type 2 Diabetes
Info more than doubled since coffee first linked to
reducing diabetes risk; unlikely just related to caffeine
Dec. 14, 2009 – Just days after the news that
coffee appears to substantially lower the risk of prostate cancer,
senior citizens today learned their favorite drink – coffee - appears to
lower the risk of developing type 2 diabetes, a major threat for older
Even better, regular or decaffeinated coffee as well as tea
all work, according to an analysis in the current issue of Archives
of Internal Medicine.
By the year 2025, approximately 380 million
individuals, mostly seniors worldwide will be affected by type 2
diabetes, according to background information in the article, which
looked at previous studies.
"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 write.
A previously published meta-analysis suggested
drinking more coffee may be linked with a reduced risk, but the amount
of available information has more than doubled since.
Rachel Huxley, D.Phil, of The George Institute for
International Health, University of Sydney, Australia, and colleagues
identified 18 studies involving 457,922 participants and assessing 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 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
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.
"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," the authors write.
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.
"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 conclude.
"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."
Editor's Note: Dr. Huxley is supported by a
Career Development Award from the National Heart Foundation of
Australia. This work was additionally supported by a grant from the
National Health and Medical Research Council of Australia; a Research
Career Development Fellowship from the UK Wellcome Trust; and a research
grant from Institut Servier, France and Assistance Publique-Hopitaux de