Recently America was atwitter over red meat.
A new study from Harvard found that each two-ounce increase in daily consumption of processed meats like bacon, hot dogs, and cold cuts was associated with a 42% greater risk of heart disease and 19% heightened chance of diabetes.
But, unfortunately, what got most of the headlines was the news on unprocessed red meats like beef, lamb, and pork. They were not linked with more heart disease or diabetes in this study.
And here’s what America heard: “Just in time for summer… chow down! Red meat is good for you!” newscasts announced, sporting images of outdoor grills jammed with sizzling steaks. Newspapers had headlines like “guilt-free hamburgers.”
“Baloney,” warned Jay Kenney, PhD, who has been studying the link between diet and increased risk of disease for the past four decades and is Nutrition Research Specialist at the Pritikin Longevity Center in Miami, Florida.
“While the media correctly reported that this study added to evidence that processed meats, loaded with salt and other damaging ingredients, are particularly unhealthy, it grossly misinterpreted the study’s findings on unprocessed meat. Never did this study say that eating red meat like burgers and steak was okay.”
The lead author of the new study, Renata Micha, PhD, agreed. In an interview with Pritikin Perspective, the Harvard research fellow stated: “It is very important to stress that unprocessed red meat was not associated with LOWER risk of heart disease and diabetes. Therefore, people should not use these findings as license to eat as much unprocessed red meats as they like.” Rather, “they should give more emphasis to increasing intake in their diet of foods that have been shown to be protective, such as fruits, vegetables, whole grains, fish, and nuts.” Yes, Dr. Micha echoes the Pritikin Eating Plan.
And the media, admonished Dr. Kenney, should give more emphasis to science that is irrefutable. “It is proven beyond any doubt that increasing saturated fat and cholesterol in the diet raises ‘bad’ LDL cholesterol levels in the blood, and all meats have some saturated fat and cholesterol. Obviously, fatty cuts are worse, but even unprocessed lean meat, especially if consumed in large amounts, will raise LDL cholesterol.
“There is also irrefutable evidence linking elevated LDL cholesterol levels to increased atherosclerosis, the underlying cause of most heart attacks and strokes in the U.S. Unless 1 + 1 no longer equals 2, it would be beyond naive to suggest that increasing meat intake would not increase coronary heart disease.”
Keep in mind, too, that there is growing evidence linking increased heme iron intake and iron stores, the result of increased red meat consumption, with heightened risk of developing not only heart disease and type 2 diabetes but also several types of cancer.
“There is also a growing body of data showing that high-temperature cooking of meat, especially grilling, frying, and broiling, generates a variety of known and suspected carcinogens as well as other troubling substances like advanced glycation end products (AGEs) that may also promote vascular disease, diabetes, and/or cancer,” pointed out Dr. Kenney.
Now, back to the study that got all the press last week. Published online in Circulation, it was an analysis of previously published studies, called a meta-analysis.
Here is one key concern: The studies the Harvard researchers reviewed were observational studies, not controlled clinical trials. “Observational studies,” explained Dr. Kenney, “are notoriously inaccurate at assessing what people actually ate. Such data hardly refute much better quality data from clinical trials.
“Controlled clinical trials, the gold standard of scientific research, have proven a strong and consistent link between eating more red meat and elevated LDL cholesterol levels, and between higher LDL levels and more coronary heart disease.”
Here’s another example of how observational studies can sometimes steer us in the wrong direction. Most have not found an association between salt intake and blood pressure, but numerous clinical trials have clearly shown that the more salt we eat, the greater our risk of high blood pressure, strokes, and heart disease.
There’s one other key issue that needs to be raised regarding this study’s claims about red meat and disease. To begin, let’s assume that the data were accurate, that people did in fact report the correct amount of meat they were eating. We’ll then assume the conclusions were correct: When the scientists compared those who ate steak and other unprocessed red meat with those who ate less (on average, four ounces less per day), they came up empty. Heart disease risk was the same.
But what we don’t know from this study is the total amount of saturated fat and cholesterol that people consumed. It is quite likely that the people who ate less red meat ate more dairy, poultry, and other foods high in saturated fat and cholesterol. If they did, they could have ended up eating similar amounts of saturated fat and cholesterol as the heavy meat eaters, and having similar cholesterol profiles and similar risks of heart disease. We will never know because this meta-analysis did not look at total amounts of saturated fat and cholesterol in people’s diets. But it’s certainly a valid question given food trends in America over the past 40 years. Since 1970, beef consumption has dipped considerably while chicken and some dairy products (especially cheese, which is very high in saturated fat) have shot up. Since 1970, the average American has tripled his cheese consumption. That’s a lot of saturated fat. And very likely, a lot of clogged arteries.
Ounce for ounce, cheeses like cheddar and monterey have about three times as much saturated fat as ground beef. Three times!
The point here is: You can cut a lot of red meat out of your diet, maybe even get rid of it completely, “but it will not likely reduce your LDL cholesterol or heart disease risk if you’re replacing your steak and burgers with Chicken McNuggets and cheese omelets,” points out Dr. Kenney. “Now, you would reduce your LDL cholesterol and heart attack risk if instead of steak and burgers you were choosing meatless chili and veggie burgers because that switch would in fact reduce your intake of saturated fat and cholesterol.”
And when it comes to red meat, you’re certainly far better off choosing lean, low-in-saturated-fat cuts like the grass-fed bison steak served at the Pritikin Longevity Center than fattier cuts, especially fatty processed meats like bacon, bologna, hot dogs, ham, and sausages. But even then, bison is a once-a-week choice, not an every-night choice, because it still has some saturated fat and cholesterol. If you eat large quantities of any food containing saturated fat and cholesterol, your LDL cholesterol is bound to go up, and with it, your risk of heart disease.
The new Harvard study concluded that just a little bit of processed meat, each additional two-ounce serving consumed daily, was linked with significant increases in heart and diabetes risk. Processed meat, with its high salt content and larger amounts of other additives, is particularly unhealthy.
This study also looked at the risk of heart disease and diabetes for each additional four-ounce serving of unprocessed meat consumed daily. It did not find a statistically significant association. Translated: Red meat was not linked with raised risk, but it was not linked with lower risk either.
What this study did not show, but what many media reports erroneously inferred, is that eating lots of unprocessed red meat was perfectly fine; it would not increase our risk of heart disease or diabetes. These reports, more intent on sensational headlines than on accurate analysis, left many people thinking, “Let’s fire up the BBQ. Let’s pile on the pork chops and steaks.” What a tragedy.