The New Scientist March 23, 2009
http://www.newscientist.com/article/dn16824-steak-and-hot-dogs-linked-to-early-death.html
Steak and hot dogs linked to early death
By Ewen Callaway
It gives a new meaning to the phrase "meat is murder": a study of more than
half a million Americans has found that consuming steaks, hot dogs and other
red and processed meats significantly increased participants' chances of
dying during the decade in which they were tracked.
Women who consumed the most red meat - 66 grams (2.3 ounces) per 1000
calories - were roughly 36% more likely to die than women who ate the least
red meat - 9.1 grams (0.3 ounces). For men, a similar difference in red meat
consumption, upped death rates by 31%.
To put it the other way around, the researchers say that 11% of deaths in
men and 16% of deaths in women could be prevented if people who eat a lot of
red meat cut their consumption.
"This is probably the biggest and most carefully done study on the
relationship between diet and mortality that I've seen," says Barry Popkin,
an epidemiologist at the University of North Carolina in Chapel Hill, who
was not involved in the study.
The study, led by researchers at the National Cancer Institute (NCI) in
Rockville, Maryland, followed about 545,000 men and women between the ages
of 50 and 71. Between 1995 and 2005, 47,976 men and 23,276 women
participating in the study died.
Additional factors?
Upon enrolment, participants filled out an extensive questionnaire of their
diet over the past year. Since no one can remember exactly what they've
eaten a year ago, the researchers asked participants exactly what they had
eaten on a previous day. They then adjusted the yearly "food diaries"
according to how good the subjects were at recalling what they ate the day
before.
The researchers also adjusted their estimates based on participants' age,
weight, smoking history, total food intake and other factors that might
confound any association between diet and mortality.
This increased the chances that researchers would uncover a real association
between red and processed meats and death rates, but these measures do not
eliminate the possibility that other factors could explain the link, says
Rashmi Sinha, the NCI epidemiologist who led the study.
"It's unlikely we're ever going to feed people meat and see what happens,"
she says.
Cancer and heart disease explain much of the association between red meat
and mortality. Men who ate the most red meat were 22% more likely to die of
cancer and 27% more likely to die of heart disease, compared with men who
ate red meat sparingly.
Women who ate the most steaks and hamburgers were 20% more likely to die of
cancer and 50% more likely to die of heart disease, compared with women who
consumed the lowest levels.
Consumption cut
Participants ate less processed meat - think hot dogs, pepperoni and sausage
- but these foods seemed even more potent. Men who consumed the highest
levels of these meats - an average of 19 grams (0.7 ounces) per 1000
calories - were 16% more likely to die during than study compared to men who
ate averaged 5 grams (0.2 ounces) per 1000 calories.
For women, the difference between 3.8 (0.1 ounces) and 16 grams (0.6 ounces)
of processed meats per 1000 calories upped the odds of death by a quarter.
"You eat a hot dog a week you're going to up, quite a bit, your risk of
death in a 10-year period," says Popkin. His advice: "Don't eat processed
meat," and consume red meat in moderation.
However, doctors and nutritionists have been offering the same advice for
years, Popkin notes, and such warnings can only go so far to reduce meat
consumption.
He argues, instead, that governments in the US and Europe ought to curtail
farm subsidies that keep meat artificially cheap, as well as factor the
environmental costs associated with meat production.
"The whole focus of the environmental movement seems to be on cars and coal,
but we have the lowly pig producing a hell of a lot of carbon," he says.
Journal reference: Archives of Internal Medicine (vol 169, p 562)