Those who eschew steak in favor of chicken because they think it's healthier may be able to put lean beef back on the menu.
That's because new research, published Tuesday in the American Journal of Clinical Nutrition, is raising questions about poultry and cholesterol.
The small study found that consuming high levels of red meat or white poultry resulted in higher blood cholesterol levels than consuming an equal amount of plant protein. The findings held even when diets contained high levels of saturated fat, which increased blood cholesterol to the same extent as all three protein sources.
The key takeaway from the study, nutritionists say, is to watch out for saturated fat, no matter the protein source. And when it comes to poultry versus red meat, "it's easier to get higher amounts of saturated fat from some cuts of red meat," said Elizabeth Kitchin, assistant professor of nutrition sciences at the University of Alabama at Birmingham who wasn't involved with the research.
Still, it was unexpected that poultry had the effect on cholesterol levels that it did.
"I was surprised that the effect of white meat on cholesterol levels was identical to the effects of red meat," said Dr. Ronald Krauss, study author and director of atherosclerosis research at Children's Hospital Oakland Research Institute.
In the study, 113 adults were randomly assigned to one of three diets for one month: rich in lean cuts of beef, lean cuts of chicken or turkey, or plant proteins. After each month, the participants' diet was changed, so that each participant ended up trying all three diets. However, half of the participants' diets, regardless of protein source, were high in saturated fat; the other half ate a low-saturated fat diet.
After each month, the researchers measured the participants' levels of LDL cholesterol, the so-called bad cholesterol.
"Keeping all else constant — even the level of animal fat — the levels were higher on both sources of meat compared to the nonmeat diet," Krauss told NBC News.
Researchers said that the findings may not affect most people who aren't at high risk for heart disease. When participants' diets were low in saturated fat, the rise in LDL was minimal regardless of whether they ate chicken or lean red meat. But for the person actively trying to bring down high levels of LDL cholesterol, researchers said, it may be worth cutting back on both red and white meats, and relying more on plant proteins.
Red meat is a source of high-quality protein, zinc, iron and vitamin B12, but most nutritionists agree that it is best to choose a lean cut in a modest portion for optimal health benefits. The positives of having red or white meat can be canceled out if too much saturated fat, from any source, is included in one’s diet.
Previous evidence shows that fatty red meat is a prime source of artery-clogging saturated fat, a factor associated with heart disease. And two studies published last year showed that people who eat red meat — but not vegetarians or people who eat only white meat such as chicken — have higher levels in the blood of a chemical called TMAO, which has been linked to higher heart disease risk.
The researchers cautioned against demonizing any food based on one study. "People often get the impression that if something raises cholesterol, it should be eliminated," Krauss said. "I don't want people to get too focused on an all or nothing approach."
Indeed, the American Heart Association recommends a combination of poultry, fish, vegetable proteins and lean red meat for a heart-healthy diet.
"For many people a varied approach including any or all of these foods within the context of high fruit, vegetable and whole grain, nuts/seeds/legume intake along with polyunsaturated or monounsaturated oils can serve as a healthy eating pattern with plenty of variety," Dr. Linda Van Horn, a volunteer nutrition expert with the AHA, told NBC News.
Other outside experts also pointed out that diet is just one factor when it comes to overall heart disease risk.
"This study focused on just saturated fat," Kitchin told NBC News. "There are a lot of other risk factors for heart disease, like extra body weight and inactivity, that are big players in heart disease."