US: Reducing red meat consumption, reducing mortality
Title: Red meat consumption and mortality
Authors: A Pan, Q Sun, A Bernstein, M Schulze, et al
Reference: Archives of Internal Medicine 2012, Published online March 12, 2012
Reviewer: Liesbeth Smit, MSc, ProCor contributing editor, freelance science writer, Amsterdam, The Netherlands
Reviewer comments: Red meat consumption has been associated with increased risks of diabetes, cardiovascular disease (CVD) and certain cancers (mostly colorectal cancer). Although consumption of red meat in the US has dropped because people began to eat more poultry instead of beef and pork, average intake of red meats is higher than the intake advised to reduce risk of these chronic diseases (less than 500g or 18oz per week, of which little processed). As the developing world will continue to consume a more Western diet, consumption of red meats may become a risk factor for diabetes, CVD, and cancer in these countries as well.
The results from the present large prospective cohort study show that increasing consumption of total, unprocessed and processed red meats by one serving a day was associated with a 12% to 20% higher risk of mortality. Eating nuts, legumes, low-fat dairy, whole grains, poultry, or fish instead of red meats was associated with a 7% to 19% lower risk for total mortality. In this population an estimated 9.3% of men and 7.6% of women would not have passed away if all individuals would consume less than half a serving (42 grams) per day of red meat.
The present findings suggest that lowering intakes of red meats-especially processed red meats such as bacon and hot dogs-may be an easy lifestyle change to reduce the risk of total mortality from CVD and cancer. Especially in countries where beef and pork consumption is increasing due to a higher standard of living, it is important to promote the substitution of red meat with other protein-rich foods in to reduce the burden of disease.
Together with other findings about the relationship between red meats and disease outcomes, this study confirms the body of evidence that suggests that lowering the intake of red meats (to once a week at most) and replacing it with other protein rich food sources may prevent many deaths from CVD and cancer.
Purpose of study: The objectives of this large prospective cohort study were to investigate the association between red meat intake and mortality from CVD and cancer during 22 years of follow-up in 37,698 men from the US-based Health Professionals Follow-up Study and during 28 years of follow-up 83,644 women in the Nurses' Health Study.
Location of study: USA
Study design: Prospective cohort
Results: This study of two large prospective cohort studies (the Health Professionals Follow-up Study and the Nurses' Health Study) examined the association between consumption of unprocessed red meats in the food frequency questionnaire that was taken from the participants every four years and the observed deaths from CVD and cancer.
Unprocessed red meats included beef, pork, or lamb as sandwich, mixed dish or main dish and hamburgers (a serving was 30z. or 85 grams). Processed red meat included bacon, hot dogs, sausage, bologna and other processed red meats, where two slices of bacon (13g) and one 45g hotdog or one piece of salami (28g) were considered a serving.
A total of 37,698 men and 83,644 women participated in this study. At the start of this cohort study, the men from the Health Professionals Follow-up Study were age 40-75 years and the women from the Nurses' Health Study were age 30-55 years. Among the men and women with a higher intake of red meat, the average physical activity level was lower, they were more likely to smoke, drink alcohol and to have a high BMI, and have a lower intake of whole grains, fruits and vegetables. The intake of red meats was 0.22 servings per day for men, and 0.53 for women in the lowest intake quintile and was 0.36 servings per day for men, and 3.10 for women.
The increase in risk of total mortality for each additional serving of red meats was 12% for total red meat, 13% for unprocessed red meat, and 20% for processed red meat. For CVD mortality this was 16% for total red meat, 18% for unprocessed red meat, and 21% for processed red meat. For cancer mortality this was 10% for total red meat, 10% for unprocessed red meat, and 16% for processed red meat. These associations were adjusted for other risk factors such as age, BMI, alcohol consumption, physical activity, smoking, consumption of total energy, whole grains, fruits and vegetables and disease history.
When they replaced red meats in their statistical models for nuts, legumes, low-fat dairy, whole grains, poultry or fish a 7% to 19% lower risk for total mortality was observed.
Only 22.8% of men and 9.6% of women had such a low red meat intake that they were considered to be in the low-risk category. If all the participants would have consumed less than 0.5 servings per day of total red meats, 8.6% of men and 12.2% of women could have prevented. For total mortality 9.3% of deaths in men and 7.6% in women could have been prevented.
Additional references: 1. WCRF/AICR's Second Expert Report, Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective. http://bit.ly/zMb119