Is Chicken or Beef Better for Cholesterol

White meat could carry the same heart health risks as red meat according to scientists who studied how beef and chicken affect cholesterol levels.

The authors of a study published in the American Journal of Clinical Nutrition concluded plant-based proteins seem to be the best option for those looking to control their blood cholesterol levels.

Past studies indicate red meat, but not poultry, can raise the risk of heart disease, while proteins found in plants can protect the cardiovascular system. It is thought the high levels of saturated fats in red meat raise the levels of low-density lipoprotein (LDL), or "bad" cholesterol in the blood, and can in turn cause heart disease. LDL particles can clog up the arteries by delivering waxy cholesterol to their walls, which leads to a build-up of plaque linked to heart disease or stroke.

It is also believed that the size of the LDL particles plays an important role in a person's chance of developing heart disease. Compared with their larger counterparts, smaller LDL particles are better at getting in the arteries to transport cholesterol.

With this in mind, the U.S team looked at how diets with different levels of saturated fats would affect levels of LDL cholesterol.

The researchers recruited 113 healthy men and women aged between 21 to 65 years-old for the study. First, they asked the participants to follow a two-week diet to check they could stick to a regime. They then randomly put them in a high saturated fat or low saturated fat diet group.

In their respective groups, the participants ate red meat, white poultry meat, and then no meat in separate four week periods punctuated by washout periods where participants went back to their normal diet. Their activity levels—which they documented in weekly logs—were kept the same, and they were instructed to stop drinking alcohol and taking vitamins during the course of the study.

The participants picked up their food— including standardized entrees, side dishes, drinks, and snacks— at the lab, where researchers also weighed them, and counselled them on their diets. Blood samples were collected at the start and finish of each diet, including the initial program lasting two weeks. Beef was the main red meat source, followed by pork; chicken was the main white meat source, followed by turkey.

Ronald Krauss, professor of medicine at the University of California, San Francisco and senior author of the study, told Newsweek that the participants primarily ate corn-fed beef, as this is the type of red meat most commonly consumed in the U.S. Lean meats were used so the team could compare the effects of adding low or high saturated fat. Processed meats weren't allowed in case the chemicals skewed the results. In the high-fat plant based groups, the substance came from tropical oils and fats, and high-fat dairy products.

Krauss said this is the first study to systematically compare the effects of red, white, and plant-based sources of protein on cholesterol levels in diets where other major nutrients were kept constant and saturated fat intake was controlled.

Based on current dietary advice to favor white meat over red, Krauss said the team had expected poultry to result in lower cholesterol levels. Instead, the research showed levels of LDL cholesterol were the same both in those who ate red meat and white meat. However, LDL levels were lower when the participants had plant-based diets.

"These results were similar whether or not the diets were high or low in saturated fat. So the result can be viewed as indicating either a cholesterol raising effect of both meats, or a cholesterol lowering effect of plant foods, or both," said Krauss.

The way the study was designed meant the researchers were unable to test the effects of different sources of red meat, for instance processed versus unprocessed lamb and beef, said Krauss. And the team could have also explored the effects of fish, said Krauss as he detailed the study's limitations.

It seems that diets high in plant proteins are preferable over those with high amounts of either red meat or white poultry for controlling blood cholesterol levels, said Krauss.

"It [the study] reinforces the need to consider food sources of nutrients such as protein, rather than the nutrients themselves, when evaluating the health effects of diets."

The research also highlighted the importance of the size of LDL cholesterol rather than just their presence in the blood when considering the potential damage to heart health, argued Krauss.

"LDL particles are felt to represent a more meaningful index of heart disease risk than the standard lab measurement of LDL cholesterol. An additional finding of this study was that in comparison to non-meat protein sources, red and white meat specifically increased amounts of large LDL particles, which have a weaker connection to cardiovascular disease than smaller LDL particles."

Similarly, eating high amounts of saturated fats increased concentrations of the larger LDL particles, said Krauss.

"Therefore, using standard LDL cholesterol level as the measure of cardiovascular risk may lead to overestimating that risk for both higher meat and saturated fat intakes, as the LDL cholesterol test may preferentially reflect levels of larger LDL particles," he argued.

Evidence suggests high levels of LDL cholesterol aren't just bad for the arteries. Last week, a study published in the journal JAMA Neurology linked these particles to early-onset Alzheimer's disease.