Is Red Meat Killing You?
This Fourth of July, what you throw on the grill is coming under fire
(Editor's note: This is an encore version of a story that first appeared on Next Avenue on May 25, 2012.)
Grilling season is in full swing, and as families flip their steaks or hot dogs this Fourth of July weekend, a chorus of experts is urging that you shift your diet to chicken, fish and veggies full time and never look back.
After all, consumption of meat, like beef, lamb, veal and pork, has long been linked to an increased risk of developing cardiovascular disease, some cancers and Type 2 diabetes.
And a recent widely publicized study from the Harvard School of Public Health has found that people who regularly eat red meat, especially processed red meat like bacon, hot dogs and salami, have a higher risk of premature death than people who get their protein primarily from such foods as beans, nuts, low-fat dairy products, chicken and fish.
The research is based on detailed analysis of two separate, long-term studies that tracked more than 120,000 men and women who worked in health care and filled out questionnaires about their diet, health and lifestyle for as long as 28 years.
Researchers discovered that, even after controlling for such variables as smoking, lack of exercise and body mass index, one serving of unprocessed red meat in a person's daily diet (3 ounces, or about the size of a deck of cards) led to a 13 percent greater risk of premature death, including a 16 percent greater risk of death from cardiovascular disease and a 10 percent greater risk of death from cancer. Worse, one serving of processed red meat in a person's daily diet led to a 20 percent greater overall risk of premature death.
Why So Harmful?
Red meat's link to major diseases has long been explored, and debated. According to the Harvard team, carcinogens produced when red meat is cooked appear to make it a risk factor for cancer. High levels of sodium in processed red meat products, as well as the presence of nitrites, which are commonly used as a preservative, might help explain the link between those items and higher death rates, the team theorized.
The study's co-authors also wrote that saturated fat and cholesterol in red meat products are likely among the main reasons for their link to a higher risk of cardiovascular disease. But a study released this spring by a team from six major medical centers claims that the main heart-offending ingredient is actually the compound L-carnitine. Abundant in red meat, L-carnitine is converted by bacteria in the gut into a compound called trimethylamine-N-oxide (TMAO), which causes atherosclerosis (hardening of the arteries).
The bottom line, according to the Harvard research team, is that if every adult analyzed by its study had eaten a half-serving less of red meat every day, 9.3 percent of premature deaths in men and 7.6 percent of premature deaths in women could have been prevented.
Red Meat's Place on Your Plate
So, should you immediately cancel this weekend's planned barbecue and purge your freezer of burgers, steaks and franks?
Not necessarily, and if it makes you feel any better, even An Pan, Harvard School of Public Health researcher and lead author of the study, says he eats one or two servings of red meat a week, usually in the form of beef or pork in Chinese dishes, although he says he never buys processed red meat products.
"Our study adds more evidence to the health risks of eating high amounts of red meat," Pan says. "I think it’s a good start to try to reduce your red meat consumption." He suggests replacing half the red meat you normally eat with chicken, fish or other sources of protein. "I think it's very easy to do," he says. "Most people can do that."
While Pan and other researchers emphasize reducing your intake of red meat, there is no conclusive evidence as of yet that completely eliminating unprocessed red meat from your diet is better for you than eating it in moderation.
"You don’t have to go totally vegetarian," says Colleen Doyle, director of nutrition and physical activity for the American Cancer Society, but most Americans have plenty of room to cut back. Only Luxembourgers, Austrians, Spaniards and Danes consume more red meat per capita than Americans do, according to analysis of United Nations data conducted by the magazine The Economist. We consume, per capita, approximately 105.7 pounds of red meat each year, according to the U.S. Census Bureau. And processed meat products represent 22 percent of all red meat and poultry consumed by Americans, according to National Cancer Institute research.
Some Questions Remain
We still have more to learn about some of the specific health risks of red meat, and the benefits of alternatives.
For example, Pan says, it’s not clear whether grass-fed beef, which has grown in popularity since his study began, is less risky than the corn-fed beef most of us eat. It is also not yet clear, Doyle says, if processed meat products made from turkey or chicken are less risky than those made from red meat, but, she adds, "any processed meat is something to be wary of, and really cutting back on processed meat is important from a colon cancer perspective."