Medical professionals long have advised meat eaters to opt for white meat, such as chicken, over red meat. But is it really the healthier diet choice? That’s what a new study aimed to figure out, and the findings surprised even the researchers themselves. Here’s what they learned.
THE STUDY
The study on the effects of red meat, white meat and plant protein was recently published in the American Journal of Clinical Nutrition. Scientists at Children’s Hospital Oakland Research Institute in California wanted to evaluate how the different protein sources affected a person’s cholesterol and risk for cardiovascular disease — especially given that dietary recommendations typically focus on avoiding red meat while the other sources haven’t been extensively studied in that regard. The assumption has been that the saturated fat in red meat is what raises a person’s risk for cardiovascular disease more than the leaner protein sources.
The researchers recruited 113 generally healthy women and men between the ages of 21 and 65 and randomly assigned them either to a group that consumed foods high in saturated fats or another that ate a diet low in saturated fats. All of the participants cycled through three test diets: a red meat diet, a white meat diet and a meatless diet. They ate each of these diets for four weeks, followed by a two- to seven-week “washout period,” in which they were permitted to resume eating their usual foods.
Participants regularly met with clinic staff to receive their study foods and dietary advice — as well as to be weighed, have their blood pressure taken and have blood drawn. They were required to maintain their weight and baseline activity level for the duration of the study.
Grain-fed beef was the primary source of red meat used for the study, as that represents most of the beef sold in the U.S. And chicken was the main white meat. Legumes, nuts, grains and soy products made up the bulk of the meatless diet. And eggs, dairy and vegetable sources offered some protein for all of the diets. Seafood and processed meats were excluded from all the diets, as the study wasn’t designed to test them and didn’t want other factors to complicate the results.
Moreover, high-fat dairy products, such as butter, were the primary sources of saturated fats to achieve the desired difference between the high-saturated fat and low-saturated fat groups. And for the meatless diet, saturated fats mostly came from tropical oils and fats.
The participants received rotating menus available at five total caloric levels. They obtained all their food and caloric beverages from the study — except for fresh produce, which they had to purchase themselves to ensure freshness. They also were not allowed to consume any alcohol during the study, even during the washout periods.
Compliance to the test diets was closely monitored to ensure quality results. So what did the researchers find out?
THE RESULTS
The researchers had hypothesized that the red meat diet high in saturated fats would raise cholesterol more than the rest of the diet combinations. But their results caught them by surprise.
“When we planned this study, we expected red meat to have a more adverse effect on blood cholesterol levels than white meat, but we were surprised that this was not the case — their effects on cholesterol are identical when saturated fat levels are equivalent,” study senior author Ronald Krauss said in a news release.
As expected, the participants who were part of the high-saturated fat group had higher total and LDL cholesterol levels (also known as “bad” cholesterol), regardless of their protein source. So for those looking to lower their cholesterol or reduce their risk of cardiovascular disease, limiting saturated fats is a good place to start. But independent of that, protein choice also seems to be a major factor. And swapping beef for chicken might not be enough.
“The results were notable, as they indicated that restricting meat altogether, whether red or white, is more advisable for lowering blood cholesterol levels than previously thought,” according to the news release. “The study found that plant proteins are the healthiest for blood cholesterol.”
The study’s authors did note that others aspects of red meat might contribute to an increased risk of cardiovascular disease — potentially more than white meat does. So it’s still too preliminary to say how they stack up against one another in totality. Those effects require further study before there can be definitive dietary guidelines.
Still, what this study does underscore is swapping animal protein for plant protein is a much healthier choice for your heart — not to mention animal welfare and the environment.
For a healthy heart, the American Heart Association recommends choosing plant protein, such as beans, as well as fish (if you eat animal products). “Omega-3 fatty acids, found in fish and some plant sources, as part of a heart-healthy diet, can help reduce the risk of heart failure, coronary heart disease, cardiac arrest and the most common type of stroke (ischemic),” it says.
If you do eat meat, the American Heart Association advises you limit each portion to about 2 to 3 ounces, choose lean cuts, remove as much fat as possible and use healthy cooking methods, such as baking. Also, avoid processed meats, as well as high-sodium seasonings.
“Many people choose not to eat meat for various reasons, including health,” the American Heart Association says. “You can get all the nutrients your body needs without eating meat.” And this new study has given all of us another good reason to opt for plant protein.
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