Contrary to popular belief, consuming red meat and white meat such as poultry, have equal effects on blood cholesterol levels, according to a study published recently in the American Journal of Clinical Nutrition.
Researchers randomly assigned 113 healthy adults, ages 21 to 65, to follow a four-week diet with high levels of either red meat, white meat (chicken and turkey), or plant-based protein (such as nuts, whole grains, soya products, and legumes). Afterward, LDL levels in the high-red-meat diet group rose, as predicted, but the researchers found that high levels of poultry had the same effect on LDL levels as red meat.
In comparison, people in the plant-protein group saw their LDL levels drop by about 7%. The researchers cited the diet's phytosterols (plant chemicals), which can lower cholesterol levels, as the most likely reason. They concluded that reducing your intake of all meat — red and white — and eating more plant proteins may be the best approach for managing LDL levels.
The study, led by scientists at Children's Hospital Oakland Research Institute (CHORI) - the research arm of UCSF Benioff Children's Hospital Oakland - surprised the researchers with the discovery 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 or not the diet contained high levels of saturated fat, which increased blood cholesterol to the same extent with all three protein sources.
Senior author of the study, Ronald Krauss, M.D., senior scientist and director of Atherosclerosis Research at CHORI said:
"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..."
Krauss, who is also a UCSF Professor of Medicine, noted that the meats studied did not include grass-fed beef or processed products such as bacon or sausage; nor did it include fish.
But 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.
This study, dubbed the APPROACH (Animal and Plant Protein and Cardiovascular Health) trial, 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.
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. Dietary guidelines, in turn, have tended to encourage the consumption of poultry as a healthier alternative to red meat. However, there had been no comprehensive comparison of the effects of red meat, white meat and nonmeat proteins on blood cholesterol until now. The study showed that plant-based proteins such as vegetables and legumes, such as beans, show the best cholesterol benefit.
"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."
The findings of this study are therefore in keeping with recommendations promoting diets with a high proportion of plant-based food. Click here for detailed advice about thriving on a plant-based diet.
Citation and link to full report:
Nathalie Bergeron, Sally Chiu, Paul T Williams, Sarah M King, Ronald M Krauss, Effects of red meat, white meat, and nonmeat protein sources on atherogenic lipoprotein measures in the context of low compared with high saturated fat intake: a randomized controlled trial, The American Journal of Clinical Nutrition, Volume 110, Issue 1, July 2019, Pages 24–33, https://doi.org/10.1093/ajcn/nqz035
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