Eating a portion of processed red meat daily can boost a person's risk of dying young by up to 20 percent, said a long-running US study of more than 120,000 people released on Monday.
While the research by Harvard University experts offers more evidence that eating red meat increases the risk of heart disease and cancer, it also counsels that substituting fish and poultry may lower early death risk.
"This study provides clear evidence that regular consumption of red meat, especially processed meat, contributes substantially to premature death," said Frank Hu, senior author of the study in the Archives of Internal Medicine.
Researchers gleaned their data from a study of 37,698 men who were followed for 22 years and 83,644 women who were tracked for 28 years.
Subjects answered surveys about their eating habits every four years.
Those who ate a card-deck-sized serving of unprocessed red meat each day on average saw a 13 percent higher risk of dying than those who did not eat red meat as frequently.
And if the red meat was processed, like in a hot dog or two slices of bacon, that risk jumped to 20 percent.
However, substituting nuts for red meat lowered total mortality risk by 19 percent, while poultry or whole grains lowered the risk 14 percent and fish did so by seven percent.
The authors said between seven and nine percent of all deaths in the study "could be prevented if all the participants consumed fewer than 0.5 servings per day of total red meat."
Processed red meat has been shown to contain ingredients such as saturated fat, sodium, nitrites and some carcinogens that are linked to many chronic ailments including heart disease and cancer.
"More than 75 percent of the $2.6 trillion in annual US health care costs are from chronic disease," said an accompanying commentary by Dean Ornish, a physician and dietary expert at the University of California, San Francisco.
"Eating less red meat is likely to reduce morbidity from these illnesses, thereby reducing health care costs."
A separate study, also led by Hu but published in Circulation, an American Heart Association journal, found that men who drank sugar-sweetened beverages daily faced a 20 percent higher risk of heart disease than men who did not.
The study tracked more than 42,000 men, most of them Caucasian, over 22 years and found higher heart risks, as higher levels of inflammation and harmful lipids known as triglycerides in daily sweet-drinkers.
The effects were not seen in men who drank as many as two sugar-sweetened beverages per week.
According to Hu, the research "provides strong justification for reducing sugary beverage consumption among patients, and more importantly, in the general population."
Heart disease is the biggest killer in the United States and top risk factors include obesity, smoking, lack of exercise, diabetes and poor eating habits.
AFP
Just in time to spoil the promise of warm-weather picnics, Harvard scientists have found that daily consumption of red meat — particularly the kind you might like to grill — may significantly increase your risk of premature death.
While this much has long been suspected, perhaps even by you, the Harvard-led study is the first nuanced analysis to calculate the risk that a serving of red meat can have on your longevity compared with other protein sources.
The study measures, for example, how much one could expect to lower their risk of early death by replacing pork and beef with poultry, fish, nuts or beans can lower the risk of early death; they found chicken was at least as healthy an alternative to red meat as beans and whole grains.
"This paper does not give a green light to a low-fat, high-carb diet," senior author Frank Hu of Harvard School of Public Health (HSPH) told LiveScience. "Instead, it underscores the importance of types or quality of protein." [7 Foods Your Heart Will Hate]
The study was published today (March 12) online in the journal Archives of Internal Medicine.
120,000 people can't be wrong
The researchers, led by An Pan at HSPH, tapped into two longitudinal health studies — the Health Professionals Follow-Up Study, and the Nurses' Health Study — which capture health and dietary information from approximately 120,000 adults who were free of cardiovascular disease and cancer at the onset of the study and followed for up to 28 years.
For these subjects, 20 percent of whom died during the study, one daily serving of unprocessed red meat such as steak or pork chops was associated with a 13 percent increased risk of dying during the study. One daily serving of processed red meat, such as a hot dog or bacon, was associated with a 20 percent increased risk.
Conversely, replacing one serving of red meat with one serving of a healthy protein source was associated with a lower mortality risk: 19 percent lower when the meat was replaced with nuts; 14 percent for poultry; 14 percent for whole grains; 10 percent for legumes; 10 percent for low-fat dairy products; and 7 percent for fish. [Top 10 Leading Causes of Death]
"This study provides clear evidence that regular consumption of red meat, especially processed meat, contributes substantially to premature death," said Hu.
Low-carb vs. low-fat?
This same group of researchers reported last year that a daily serving of cold cuts or hot dogs was associated with a 50 percent increased risk of developing diabetes. Yet the researchers are not anti-meat, per se.
Missing entirely from the new Harvard study is the word "carbohydrate." The study merely looked at different forms of protein sources and found beef and pork to be unhealthier compared with other sources. Both Hu and co-author HSPH colleague Walter Willett have said that added sugar in drinks and in snack foods as well as the simple carbohydrates found in potatoes, white flour and processed foods are the primary causes of obesity and diabetes.
Also, their previous studies have found that a moderately low-carbohydrate diet that includes healthy sources of fat and protein — such as olive oil, nuts, poultry, fish, whole grains and legumes — can better lower the risk of premature death from cardiovascular disease than low-fat, high-carb diets.
Therefore, if you go (or stay) in the low-carb direction, Hu advises that you choose your fats and proteins carefully. "All low-carb diets are not created equal," nor are high-carb diets, he said.
Ornish vs. Atkins?
Nevertheless, Dean Ornish, a leading supporter for a low-fat, plant-based diet naturally high in complex carbohydrates, was thrilled with the Harvard study results and wrote an adjoining commentary.
"What we include in our diet is as important as what we exclude, so substituting healthier foods for red meat provides a double benefit to our health," Ornish wrote in the commentary. "We have a spectrum of choices; it's not all or nothing."
For Ornish, those choices would be everything he has advocated for years: the complex, "good" carbs found in whole grains, beans and other vegetables; the "good" omega-3 fats found in some fish and in flaxseed; and protein from beans, nuts, whole grains and fish.
Ornish's gleeful commentary aside, the new Harvard study isn't a complete assault on the Atkins' diet and similar meat-heavy, low-carb diets. Any diet loaded with hamburger, bacon and sausage can lead to premature death, the study reveals, but poultry appears to be at least as healthy an alternative as beans and whole grains.
So what is it about red meat that makes it unhealthier than other protein sources? The Harvard scientists aren't sure. The saturated fat in red meat might not be the sole culprit, as long suspected, they said. The deleterious effects might be a result of the combination of heme iron (iron that comes from hemoglobin, the protein in red blood cells that delivers oxygen to our cells), sodium, nitrates and other chemicals that are created when cooking red meat ... in addition to, of course, all that delicious saturated fat.
Christopher Wanjek is the author of the books "Bad Medicine" and "Food At Work." His
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