Major study finds an effect, but critics say meat offers important nutrients
MONDAY, March 23 (HealthDay News) -- Diets high in red meat and in processed meat shorten life span not just from cancer and heart disease but from Alzheimer's, stomach ulcers and an array of other conditions as well, a U.S. National Cancer Institute study has found.
In fact, reducing meat consumption to the amount eaten by the bottom 20 percent seen in the study would save 11 percent of men's lives and 16 percent of women's, according to the study.
"The consumption of red meat was associated with a modest increase in total mortality," said Rashmi Sinha, lead author of the study in the March 23 issue of Archives of Internal Medicine.
"This fits together with the findings of the American Institute for Cancer Research and the World Cancer Research Fund and the American Cancer Society, which recommend limiting the consumption of red meat," added Sinha, who is a senior investigator with the nutrition epidemiological branch in the cancer epidemiology and genetics division at the Cancer Institute. "This is something new in the sense of mortality."
Previous studies of red meat had mostly found an association with cancer incidence. The authors pointed out that many pooled studies had been conducted by vegetarian groups.
Last year, U.S. National Cancer Institute researchers reported that a quarter-pound hamburger or a small pork chop eaten daily could put you at increased risk for a variety of cancers. The message from the latest study echoes that finding: The more red meat and processed meat you eat, the greater your risk for dying of cancer.
But the American Meat Institute objected to the conclusion, saying in a statement that the study relied on "notoriously unreliable self-reporting about what was eaten in the preceding five years. This imprecise approach is like relying on consumers' personal characterization of their driving habits in prior years in determining their likelihood of having an accident in the future."
"Meat is an excellent source of zinc, iron, B12 and other essential vitamins and minerals," the statement continued. "The U.S. Dietary Guidelines say to eat a balanced diet that includes lean meat. In this way, you derive a wide array of nutrients from many different sources. It's the best return on a nutritional investment you can get."
Dr. Michael Thun, vice president emeritus of epidemiology and surveillance research at the American Cancer Society, however, said the study's findings "support previous studies and also support the American Cancer Society nutrition guidelines."
Those guidelines include choosing fish, poultry or beans instead of beef, pork and lamb; choosing leaner cuts of meat; and baking, broiling or poaching meat rather than frying or charbroiling it.
For the study, the researchers looked at what more than a half-million people, ages 50 to 71, were eating over the span of a decade. Participants tended to be white and educated with fewer smokers and more vegetable-and-fruit eaters than in the general population. During that time, more than 71,000 people died.
Men and women eating the highest amount of red meat were found to have a 31 percent and 36 percent, respectively, higher risk of dying from any cause than those eating the least amount.
Women eating the most processed meat were 25 percent more likely to die early than those eating the least of this type of meat, while men had a 16 percent increased risk, the study found.
Causes of death for those in the study included diabetes, Alzheimer's disease, ulcers, pneumonia, influenza, liver disease, HIV, tuberculosis, chronic obstructive pulmonary disease and more.
Dying from cancer also was more likely among those eating the most red meat: 22 percent higher for men, 20 percent for women. The risk for death from cancer increased 12 percent for men and 11 percent for women who ate the greatest amount of processed meat.
Similarly, the risk of dying from cardiovascular disease was higher by 27 percent for men and 50 percent for women; for processed red meat, the risk was 9 percent higher for men and 38 percent higher for women.
However, people who ate the most white meat showed a lower risk of dying.
The authors also noted a 24 percent higher risk of dying from heart problems among men who had never smoked and who ate more white meat. Women faced a 20 percent higher risk.
Meat contains many carcinogens as well as saturated fat, which might explain the increased mortality risk, the authors stated.
Dr. Jay Brooks, chairman of hematology/oncology at Ochsner Health System in Baton Rouge, La., described the study's findings as "provocative."
"The question is how much of it is the meat and how much is the extra calories," Brooks said. "Calories per se are a strong determinant for death from cancer and heart disease. This should make us think about our calorie intake."
The American Dietetic Association has more on healthy eating.
SOURCES: Rashmi Sinha, Ph.D., senior investigator, nutrition epidemiological branch, division of cancer epidemiology and genetics, U.S. National Cancer Institute, Bethesda, Md.; Michael Thun, M.D., vice president emeritus, epidemiology and surveillance research, American Cancer Society, Atlanta; Jay Brooks, M.D., chairman, hematology/oncology, Ochsner Health System, Baton Rouge, La.; March 23, 2009, statement, American Meat Institute, Washington, D.C.; March 23, 2009, Archives of Internal Medicine
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