Java lovers, take heart. A large
prospective study suggests that – far from being bad for your health – that
steaming cuppa is actually associated with a lower risk of death.
Analysis of a large prospective study
of more than 400,000 people found that men who drank four to five cups of
coffee daily reduced their risk of death over a 13-year period by 12%, while
women's risk dropped by 16%, according to Neal Freedman, PhD, of the National
Cancer Institute, and colleagues.
The inverse associations were seen
for deaths due to heart disease, respiratory disease, stroke, injuries and
accidents, diabetes, and infections, but not for deaths due to cancer, the
researchers found. On the other hand, a suite of other behaviors that
often go hand-in-hand with coffee drinking – smoking, lack of exercise, and
poor diet – usually combine to mask the benefit, the researchers noted in the
May 17 issue ofThe New England Journal of Medicine.
Freedman and colleagues cautioned
that the study could not prove that coffee is good for you.
"It may be that there's
something that goes along with coffee-drinking that's affecting our results
that we couldn't take into account in our analysis," Freedman told
But, together with previous research,
he said, the findings provide "some reassurance that coffee drinkers don't
have a higher risk of death (and suggest) that there might be some benefit from
drinking coffee."
Indeed, the findings are not
surprising, according to Frank Hu, MD, PhD, of the Harvard School of Public
Health, who was senior author on a 2008 study that also found an apparent benefit for
coffee drinking.
"All the evidence is coming
together to indicate a potential health benefit of regular coffee
consumption," Hu told
The only way to prove the benefit
exists, Hu said, would be to conduct a large randomized trial, but such a study
"may not be feasible" because it would need too many participants.
In the meantime, a large prospective
cohort, such as the National Institutes of Health–AARP Diet and Health Study
analyzed by Freedman and colleagues, provides the "best available
evidence."
The NIH-AARP cohort has been running
since 1995 and includes 229,119 men and 173,141 women who were 50 to 71 when
the study started. Over the period from 1995 through 2008, Freedman and
colleagues reported, 33,731 men and 18,784 women died.
In an analysis that only took age
into account, coffee consumption was associated with an increased risk of
death, they reported.
But coffee drinkers were also more
likely to smoke, to eat more red meat and fewer fruits and vegetables, to drink
alcohol, and to have less vigorous physical activity.
When those factors were taken into
account, Freedman and colleagues found, coffee emerged as being inversely
associated with all-cause mortality, as well as a range of major causes of
death.
Compared with non-drinkers, there was
little effect for those who drank some coffee, but less than a cup a day. But
for more coffee, the odds of death dropped significantly. Specifically:
· - For those who drank one cup a day, the odds ratios for death were 0.94
for men and 0.95 for women (95% CI 0.90 to 0.99 and 0.90 to 1.01,
respectively).
· - For two or three cups a day, the odds ratios for death were 0.90 for men
and 0.87 for women (95% CI 0.86 to 0.93 and 0.83 to 0.92, respectively).
· - For four or five cups a day, the odds ratios for death were 0.88 for men
and 0.84 for women (95% CI 0.84 to 0.93 and 0.79 to 0.90, respectively).
· - And for six or more cups a day, the odds ratio for death were 0.90 for
men and 0.85 for women (95% CI 0.85 to 0.96 and 0.78 to 0.93, respectively).
·
For both men and women the trend was significant at P<0.001.
While most of the outcomes showed a
benefit for coffee, "the effect was modest," Freedman said.
Indeed, other experts said other
behavioral changes are likely to be more useful than drinking more coffee.
"Based on this study alone, I
would not tell people to start drinking more coffee to lower their risk of
death," said Lona Sandon, RD, of UT Southwestern Medical Center in Dallas.
"There are other things with
bigger impact on mortality that they probably should be doing," Sandon
said in an email to MedPage Today and ABC News.
Freedman told MedPage Today
that people should consult their physicians before making a change - or not -
in their diet.
Sandon also questioned one of the
acknowledged limitations of the study -- that the coffee consumption was
measured only at the beginning. "It is possible that their coffee-drinking
habits changed over the 12 years of the study," she said.
Again Freedman agreed, but noted that
other studies have shown that coffee drinking as a part of diet is relatively
stable over time.
The bottom line, Sandon said, is to
"stop smoking, be more physically active, eat your fruits, veggies, whole
grains, and healthy fats, and a little coffee doesn't appear to hurt."
The study is well done and the
conclusions are supported by the data, argued Peter McCullough, MD, of the St.
John Providence Health System in Detroit.
In an email to MedPage Today and
ABC News, McCullough noted that even decaffeinated coffee appeared to be
beneficial - "good news" for people who like coffee but fear
caffeine.
But he and others called for a deeper
understanding of the complex mix of compounds found in coffee.
"If you are not a coffee
drinker, this study is not a good enough reason to start," commented
Cheryl Williams, RD, of Emory Heart & Vascular Center in Atlanta.
Williams said in an email to MedPage
Today and ABC News that she's not confident coffee is truly
beneficial, given that other factors might also play a role in the outcomes
reported by Freedman and colleagues.
"Overall," she said,
"more research needs to be done to truly understand the compounds in
coffee (including those unknown) and their biological activity and effect on
health."
Tomado de: MedPage Today.
