According to a new study published in The BMJ, substituting high quality plant foods such as legumes, nuts, or soy for red meat might reduce the risk of coronary heart disease; substituting whole grains and dairy products for total red meat, and eggs for processed red meat, might also reduce this risk.
Substantial evidence suggests that high consumption of red meat, especially processed red meat, such as bacon, hot dogs, sausages and salami, is associated with an increased risk of death and major chronic diseases, including coronary heart disease.
Studies that show inconsistent results often fail to compare red meat with similar protein and energy sources.
To address these problems, Dr. Laila Al-Shaar from Harvard T.H. Chan School of Public Health and colleagues examined the relation between total, processed, and unprocessed red meat and risk of coronary heart disease and estimated the effects of substituting other protein sources for red meat with coronary heart disease risk.
The researchers analyzed data from 43,272 U.S. men (average age 53) enrolled in the Health Professionals Follow-Up Study.
Participants filled in a detailed diet questionnaire in 1986 and every four years thereafter, up to 2016, and provided information on their medical history and lifestyle.
Medical records were used to track coronary heart disease events (fatal and non-fatal) over this 30-year period.
After taking account of other cardiovascular disease risk factors, the researchers found that for every one serving per day, total red meat was associated with a modest (12%) higher risk of coronary heart disease.
Similar associations were seen for unprocessed (11% higher risk) and processed red meat (15% higher risk).
However, compared with red meat, intake of one serving per day of combined plant protein sources, including nuts, legumes (such as peas, beans and lentils), and soy was associated with a 14% lower risk of coronary heart disease.
This risk was lower still (18%) among men over the age of 65, and when compared with processed red meat (17%).
Substituting whole grains and dairy products (such as milk, cheese and yoghurt) for total red meat and eggs for processed red meat were also associated with lower coronary heart disease risk. This association was particularly strong among younger men, in whom the replacement of red meat with egg was associated with a 20% lower risk of coronary heart disease.
Replacing red meat with total fish was not associated with coronary heart disease risk.
“But this could be due to cooking method (i.e. deep frying) and the fact that this food group also included processed fish products,” the scientists said.
“Our study shows that greater intakes of total, unprocessed, and processed red meat were associated with a higher risk of coronary heart disease, independent of other dietary and non-dietary cardiovascular disease risk factors,” they added.
“Substituting whole grains or dairy products for total red meat and substituting eggs for processed red meat were also associated with a lower coronary heart disease risk.”
“These findings are consistent with the effects of these foods on low density lipoprotein cholesterol levels and support a health benefit of limiting red meat consumption and replacement with plant protein sources. This would also have important environmental benefits.”
Laila Al-Shaar et al. 2020. Red meat intake and risk of coronary heart disease among US men: prospective cohort study. BMJ 371: m4141; doi: 10.1136/bmj.m4141