PHOENIX – Consumption of red meat, particularly the processed form, is linked to a higher risk of developing coronary heart disease in men, results from a large prospective analysis demonstrated.
“The findings of this study are in line with randomized trials showing that the consumption of red meat, as compared with plant-based protein sources, increases LDL cholesterol levels, and with previous studies on red meat and risk of coronary heart disease,” lead study author, said in an interview in advance of the Epidemiology and Prevention/Lifestyle and Cardiometabolic Health meeting.
According to Dr. Al-Shaar, a postdoctoral research fellow in the department of nutrition at the T.H. Chan School of Public Health at Harvard University, Boston, most of the existing studies on red meat and heart disease have examined the impact of increasing consumption of red meat while decreasing consumption of all other foods. For the current study, she and her colleagues used a substitution analysis approach to understand how replacing red meat (total, processed, or unprocessed) with another protein-rich food was associated with the risk of heart disease. “This would potentially provide more specific guidance for healthier alternatives for those planning to cut down their red meat intake,” she said.
She and her colleagues prospectively followed 43,259 men in the Health Professionals Follow-up Study (1986-2012) who had no known history of cancer or cardiovascular disease. Diet was assessed by a standardized and validated food frequency questionnaire that was updated every 4 years. Dr. Al-Shaar and her colleagues used multivariate Cox models to estimate hazard ratios and 95% confidence intervals of CHD risk across categories of red meat consumption. They performed substitution analyses by comparing coefficients in models including alternative foods as continuous variables.
Over roughly 933,000 person-years of follow-up, the researchers documented 4,148 incident CHD cases. Of these, 1,680 were fatal. After multivariate adjustment for dietary and nondietary risk factors, both total and processed red meat intake were associated with a modestly higher risk of CHD (hazard ratio for a one serving/day increment, 1.08; 95% confidence interval, 1.01-1.14 for total red meat; and HR, 1.13; 95% CI, 1.03-1.22 for processed red meat). Substitutions of one serving per day of other foods (including nuts, legumes, soy, whole grains, and low- and high-fat dairy) for one serving per day of total red meat were associated with a 10%-47% lower CHD risk.
Stronger inverse associations were observed between some of these substitutions for red meat and risk of fatal CHD. Substituting nuts lowered the risk of fatal heart disease by 17%, while replacing red meat with whole grains was linked to a 48% reduction in that outcome. Those associations were more pronounced when replacing processed red meat.
“Processed meats and meats in general have been thought to be potentially not favorable in terms of cardiovascular disease and cardiovascular disease risk,”, professor emeritus of medicine at the University of Colorado Anschutz Medical Campus, Aurora, said in an interview. “Now we have increasing data that not only is there a negative cardiovascular disease impact of animal protein, but we see this on all-cause mortality, including cancer.”
Dr. Al-Shaar said that the findings “support current recommendations to limit consumption of red meat and suggest that high-quality plant-based proteins such as nuts, legumes, and soy are good alternatives for individuals planning to have better food choices and healthier eating patterns.”
She acknowledged certain limitations of the study, including its observational design and the fact that it was limited to non-Hispanic white health professionals, “thus limiting the generalizability of its findings to the whole population.”
Dr. Eckel, who is a past president of the American Heart Association, underscored the importance of one’s overall diet in mitigating the risk of developing coronary heart disease. “It’s not simply substituting animal protein with plant protein,” he said. “Fruits and vegetables and whole grains, lean protein from fish – a Mediterranean-style diet – is what the AHA recommends.”
Dr. Al-Shaar reported having no financial disclosures. The study was supported by a T32 training grant from the National Institutes of Health and by other grants from the NIH. The meeting was sponsored by the AHA.
SOURCE: Al-Shaar L et al. Epi/Lifestyle 2020, Abstract .