Replacing red meat with high-quality plant foods such as beans, nuts or soy may be associated with a reduced risk of coronary heart disease (CHD), suggests a published study. BMJ Today.
Substituting whole grains and dairy products for total red meat and eggs for processed red meat can also reduce this risk.
Considerable evidence shows that high consumption of red meat, especially processed red meat, such as bacon, hot dogs, sausages and salami, is associated with 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 issues in study design and analysis, a team of US researchers examined the relationship between total, processed and unprocessed red meat and risk of CHD and estimated the effects of substituting other protein sources for red meat on CHD risk.
Their findings are based on data from the Health Professionals Follow-Up Study of 43,272 US men (mean age 53) who were free of cardiovascular disease and cancer at the time of enrollment.
Participants completed a detailed diet questionnaire in 1986 and every four years thereafter, until 2016, and provided information about their medical history and lifestyle.
Medical records were used to track CHD events (fatal and non-fatal) during this 30-year period. During this period, 4,456 CHD cases were recorded of which 1,860 were fatal.
After accounting for other cardiovascular disease risk factors, the researchers found that for each daily serving, total red meat was associated with a modest (12%) higher CHD risk. Similar associations were seen for unprocessed (11% greater risk) and processed red meat (15% greater risk).
However, when compared with red meat, eating one serving per day from a combination of plant protein sources including nuts, beans (such as peas, beans and lentils) was associated with a 14% lower risk of CHD.
This risk was even lower in men over 65 (18%), and compared with processed red meat (17%).
Substituting whole grains and dairy products (such as milk, cheese, and yogurt) for total red meat and eggs for processed red meat were also associated with lower CHD risk. This association was particularly strong among younger men, in whom replacing red meat with eggs was associated with a 20% lower CHD risk.
Replacing red meat with total fish was not associated with CHD risk. But researchers say this may be due to the cooking method (i.e. deep frying) and the inclusion of processed fish products in this food group.
This is an observational study, so causation cannot be established, and despite adjusting for important personal and lifestyle factors, the researchers cannot rule out the possibility that other unproven factors may have influenced their results.
What’s more, the study participants were mainly white health professionals so the results may not be more widely applicable.
Still, this was a large study with repeated dietary measurements during a 30-year follow-up, suggesting that the findings withstand scrutiny.
As such, they state that their study shows that higher intakes of total, unprocessed, and processed red meat are associated with higher risk of CHD, independent of other dietary and non-dietary cardiovascular disease risk factors.
Substituting whole grains or dairy products for whole red meat and substituting eggs for processed red meat were also associated with lower CHD risk, they added.
“These findings are consistent with the effect of these foods on low-density lipoprotein cholesterol levels and support the health benefits of limiting red meat consumption and replacing it with plant protein sources,” they explain.
It would also have important environmental benefits, they concluded.