Substituting whole grains, dairy and eggs might also reduce risk, findings show
BMJ
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 in study design and analysis, a team of US researchers examined the relation between total, processed, and unprocessed red meat and risk of CHD and estimate the effects of substituting other protein sources for red meat with CHD risk.
Their findings are based on data
from 43,272 US men (average age 53) from the Health Professionals Follow-Up
Study who were free from cardiovascular disease and cancer when they enrolled.
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
CHD events (fatal and non-fatal) over this 30-year period. During this time,
4,456 CHD events were documented of which 1,860 were fatal.
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 CHD. 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 CHD.
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 CHD 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 CHD.
Replacing red meat with total fish
was not associated with CHD risk. But the researchers say this could be due to
cooking method (ie. deep frying) and the fact that this food group also
included processed fish products.
This is an observational study, so
can't establish cause, and despite adjusting for important personal and
lifestyle factors, the researchers can't rule out the possibility that other
unmeasured factors might have influenced their results.
What's more, study participants were
mainly white health professionals so the findings may not be more widely
applicable.
Nevertheless, this was a large study
with repeated measures of diet during 30 years of follow-up, suggesting that
the findings withstand scrutiny.
As such, they say their study shows
that greater intakes of total, unprocessed, and processed red meat were
associated with a higher risk of CHD, independent of other dietary and
non-dietary cardiovascular disease risk factors.
Substituting whole grains or dairy
products for total red meat and substituting eggs for processed red meat were
also associated with a lower CHD risk, they add.
"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," they explain.
This would also have important
environmental benefits, they conclude.
