Red and processed meat consumption is associated with a slightly but significantly higher risk of cardiovascular disease (CVD) and all-cause mortality, a large and ‘carefully analysed’ new study* from the US has found. The team behind the research said in JAMA Internal Medicine that their ‘robust’ results contradict those from a recent ‘controversial’ meta-analysis that had argued that people needn’t cut their meat consumption.
The researchers analysed pooled data from six cohorts in the US, totalling 29,682 men and women (mean age of 53.7 years at baseline) who had completed detailed dietary questionnaires at baseline from 1985 to 2002, and were then followed for up to three decades. They calculated hazard ratio (HR) and adjusted 30-year absolute risk difference (ARD) for incident CVD (a composite end point of coronary heart disease, stroke, heart failure, and CVD deaths) and all-cause mortality, comparing people who ate two servings a week of meat or fish with those who ate none.
They reported that eating processed meat (adjusted HR 1.07; adjusted ARD 1.74%), unprocessed red meat (HR 1.03; ARD 0.62%), or poultry (HR 1.04; ARD, 1.03%) was significantly associated with incident CVD. Fish intake was not significantly associated with incident CVD (HR 1.00; ARD 0.12%).
Intake of processed meat (HR 1.03; ARD 0.90%) or unprocessed red meat (HR 1.03; ARD 0.76%) was significantly associated with all-cause mortality. Intake of poultry (HR 0.99; ARD −0.28%) or fish (HR 0.99); ARD −0.34%) was not significantly associated with all-cause mortality.
The authors explained that their study had certain limitations, including dietary intake being self-reported only at baseline whereas participants’ dietary behaviours might have changed over time; and cooking methods were not considered. They pointed out that fried chicken, especially deep fat-fried sources that contribute trans-fatty acids, and fried fish intake have been positively linked to chronic diseases. Furthermore, it had not been able to show causality.
But they argued that although a ‘controversial’ meta-analysis published last November had recommended that people needn’t reduce the amount of red meat and processed meat they eat, their own study had now shown that the link to CVD and mortality was ‘robust’. They said: “These findings suggest that, among US adults, higher intake of processed meat, unprocessed red meat, or poultry, but not fish, was significantly associated with a small increased risk of incident CVD, whereas higher intake of processed meat or unprocessed red meat, but not poultry or fish, was significantly associated with a small increased risk of all-cause mortality. These findings have important public health implications and should warrant further investigations.”
They commented: “It’s a small difference [in risk], but it’s worth trying to reduce red meat and processed meat like pepperoni, bologna and deli meats. Red meat consumption also is consistently linked to other health problems like cancer.
“Modifying intake of these animal protein foods may be an important strategy to help reduce the risk of cardiovascular disease and premature death at a population level…
“Fish, seafood and plant-based sources of protein such as nuts and legumes, including beans and peas, are excellent alternatives to meat and are under-consumed in the US.”
*Zhong VW, Van Horn L, Greenland P, et al. Associations of processed meat, unprocessed red meat, poultry, or fish intake with incident cardiovascular disease and all-cause mortality. JAMA Intern Med. Published online February 03, 2020. doi:10.1001/jamainternmed.2019.6969