It also found that reducing red meat intake while increasing healthy protein sources, such as eggs and fish, whole grains and vegetables, may lower the risk over time.
High intake of beef, pork and lamb has been previously linked with a higher risk of type 2 diabetes, cardiovascular disease, certain types of cancers and premature death. But little is known about how changes in red meat intake may influence risk of death.
To explore this, researchers from China and the United States looked at the link between changes in red meat consumption over eight years, and then assessed mortality over a further eight years.
The study used data from over 81,000 Americans who completed a questionnaire that asked how often they ate various foods.
During the study period, just over 14,000 subjects died. The leading causes were cardiovascular disease, cancer, respiratory disease and neurodegenerative disease.
After adjusting for age and other potentially influencing factors, it was found that those who increased their red meat intake by at least 3.5 servings a week over eight years had a 10% higher risk of death in the next eight years.
These associations were largely consistent across different age groups, levels of physical activity, dietary quality, smoking and alcohol consumption habits.
Overall, reducing red meat intake while eating more whole grains, vegetables, or other protein foods such as poultry without skin, eggs and fish, was associated with a lower risk of death among both men and women.
For instance, swapping out one serving per day of red meat for one serving of fish over eight years was linked to a 17% lower risk of death in the subsequent eight years.
The authors said they recognised some limitations, such as they did not look at the reasons for changes in red meat consumption which could have influenced the results.
The findings provide “a practical message to the general public of how dynamic changes in red consumption is associated with health,” they wrote.
“A change in protein source or eating healthy plant based foods such as vegetables or whole grains can improve longevity.”
Assessing the study, Professor John Funder of the Centre for Neuroscience at The University of Melbourne, called it “a classic dreadnought” with “all guns firing”.
“It's all very convincing. The data show that processed meats are more dangerous than non-processed meats; so far, so good, and not unexpected,” he said.
“What the study does not address head-on is whether the findings can be generalised. Bacon in the US is fine strips of pork fat with thin red lines of meat—maybe 20% or the total—but hamburgers fail to get a mention.
“Those of us that have been taken out to eat in the US know that feedlot beef is much more marbled than our grass-fed, pork served in lashings, and lamb is almost non-existent.”
The study also only gives a passing mention to he fact that non-processed meat had previously been associated with increased mortality in the American population, but not in those in Europe or Asia.
“Possibly the most obvious omission is the possibility that what we eat with steak or pork chops may be a major contributor to the issue in the US,” he added.
Source: BMJ
https://doi.org/10.1136/bmj.l2110
“Association of changes in red meat consumption with total and cause specific mortality among US women and men: two prospective cohort studies”
Authors: Yan Zheng, et al.