Study shows red, white meat equally impact health
Consuming red meat and white meat have equal effects on blood cholesterol levels, according to a new study published in the American Journal of Clinical Nutrition.
The study, the Animal and Plant Protein and Cardiovascular Health (APPROACH) trial led by scientists at Children's Hospital Oakland Research Institute (CHORI) in California, looked at generally healthy men and women age 21 to 65 years old with a body mass index between 20 and 35. Participants were randomly assigned to one of two groups, high or low saturated fatty acid (SFA), and within each allocated to red meat, white meat, and nonmeat protein dieted for four weeks in each in random order. The primary outcomes were low-density lipoprotein cholesterol, apolipoprotein B (apoB), small and medium LDL particles, and total or high-density lipoprotein cholesterol, according to the study abstract.
Researchers analyzed data from participants who completed all three dietary protein assignments, 61 from the high SFA group and 52 from the low SFA group. They found that consuming high levels of red meat or white poultry resulted in higher blood cholesterol levels than consuming a comparable amount of plant proteins. Moreover, this effect was observed whether the diet contained high levels of saturated fat, which increased blood cholesterol to the same extent with all three protein sources, according to Ronald Krauss, MD, senior scientist and director of atherosclerosis research at CHORI.
"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” he said in a statement. “Their effects on cholesterol are identical when saturated fat levels are equivalent.”
Krauss noted that the meats studied did not include grass-fed beef or processed products such as bacon or sausage, nor did it include fish. However. 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. The study found that plant proteins are the healthiest for blood cholesterol.
The study also found that consuming high amounts of saturated fat increased concentrations of large cholesterol-enriched LDL particles, which have a weaker connection to cardiovascular disease than smaller LDL particles, researchers said.
Similarly, red and white meat increased amounts of large LDL in comparison to nonmeat diets. Therefore, using standard LDL cholesterol levels as the measure of cardiovascular risk may lead to overestimating that risk for both higher meat and saturated fat intakes, as standard LDL cholesterol tests may primarily reflect levels of larger LDL particles.
Consumption of red meat has become unpopular during the last few decades over concerns about its association with increased heart disease. Government dietary guidelines have encouraged the consumption of poultry as a healthier alternative to red meat.
There had been no comprehensive comparison of the effects of red meat, white meat, and nonmeat proteins on blood cholesterol until now, Krauss said. Nonmeat proteins such as vegetables, dairy, and legumes, such as beans, show the best cholesterol benefit, he said.
"Our results indicate that current advice to restrict red meat and not white meat should not be based only on their effects on blood cholesterol," Krauss said. "Indeed, other effects of red meat consumption could contribute to heart disease, and these effects should be explored in more detail in an effort to improve health."