Meat Consumption and Mortality Risk

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ResearchBlogging.org

According to a study published recently in the Archives of Internal Medicine, a high intake of red or processed meat increases the risk of death [1]. In contrast, those consuming white meat had a decreased risk of both total mortality and cancer mortality. Two years ago, a similar study identified an association between red and processed meat and cancers of the colorectum and lung [2], but this is the first large-scale study to assess the relationship between red, white and processed meat consumption and the overall risk of death.

Researchers prospectively (meaning in real time) investigated red, white and processed meat consumption as risk factors for total mortality, cancer mortality and cardiovascular disease (CVD) mortality. The dietary habits of more than a half-million men and women aged 50 to 71 years were assessed in 1995 using a 124-item food frequency questionnaire. Cohort members were then followed-up over a 10 year period (i.e. from 1995 to 2005).

meat

Red meat intake was calculated using information on the frequency of consumption and portion size for all types of beef and pork, including steak, hamburger, hotdogs, cold cuts, ham, pork sausage, liver and bacon as well as meats in foods such as pizza, chili, lasagna and stew. White meat included chicken, turkey, fish, poultry cold cuts, chicken mixtures, canned tuna, low-fat sausages and low-fat hotdogs made from poultry. Processed meat included bacon, red meat sausage, poultry sausage, luncheon meats (red and white meat), cold cuts (red and white meat), ham, regular hotdogs and low-fat hotdogs made from poultry. Although components making up red or white and processed meats can overlap (e.g. bacon, ham, cold cuts, etc.), the meat groups were not used in the same statistical models and are not duplicated in any one analysis.

meat-intake

The cohort was divided into five equal groups (Q1 — Q5). The tables below show the hazard ratios (meaning the measure of how often death occurred in one group compared to another over time) for total mortality, cancer mortality and cardiovascular disease (CVD) mortality as change in risk relative to the first quintile. Several statistical analyses were performed to identify additional variables that were used to develop a fully adjusted final model. The final adjusted model included a number of variables in addition to meat intake, including age, education, marital status, family history of cancer, race, body mass index, smoking history, frequency of vigorous physical activity, total energy intake, alcohol intake, vitamin supplement user, fruit and vegetable consumption, and, in women, menopausal hormone therapy.

Results

Over the 10 year follow-up period from 1995 to 2005, there were 47,976 male deaths and 23,276 female deaths. The scientists found that individuals in the highest group of red meat intake tended to consume a slightly lower amount of white meat but a higher amount of processed meat compared with those in the lowest group (see the table above).

Red meat

Overall, there was an increased risk of total mortality, cancer mortality and cardiovascular disease mortality in both men and women. Based on a 2000 calorie/day diet, men eating 4.8 ounces (136.2 grams) of red meat daily had a 31% increased risk of mortality over a given decade than men that consumed just 0.7 ounces (18.6 grams). Women eating 4.6 ounces (131.8 grams) of red meat daily had a 36% increased risk of mortality over a given decade than women who consumed just 0.6 ounces (18.2 grams)

red-meat-risks

White meat

Men and women who consumed less white meat (those in Q5 compared to Q1) had a decreased risk of total mortality and cancer mortality. For men and women with higher intake of white meat, there was a small increase in risk for cardiovascular disease mortality.

Based on a 2000 calorie/day diet, men eating 2.2 ounces (61.8 grams) of white meat daily had an 8% decreased risk of mortality over a given decade that men who consumed 2.6 ounces (73.2 grams). Women eating 2.5 ounces (70.6 grams) of white meat daily also had an 8% decreased risk of mortality over a given decade that women who consumed 2.6 ounces (74.8 grams).

white-meat-risks

Processed meat

There was an increased risk of total mortality, cancer mortality and cardiovascular disease mortaility in the group with the highest intake of processed meat compared to the lowest.

Based on a 2000 calorie/day diet, men eating 1.4 ounces (38.8 grams) of processed meat daily had a 16% increased risk of mortality over a given decade that men who consumed 0.4 ounces (10.2 grams). Women eating 1.1 ounces (32.0 grams) of processed meat daily had a 25% increased risk of mortality over a given decade that women who consumed 0.3 ounces (7.6 grams).

processed-meat-risks

Conclusions

The researchers calculated that 11% of the deaths in men and 16% of the deaths in women could be prevented if people decreased their red meat consumption to the level consumed by the first quintile (Q1).

Let’s put all of these numbers in perspective.

The difference in daily red meat consumption between the highest and lowest groups studied is approximately 4 ounces (113.4 grams) or, say, a quarter-pound hamburger. So we’re not talking about large amounts of red meat here. The take home message? One hamburger may dramatically affect your risk of dying. Remember, the additional 4 ounces of red meat consumed daily (Q5 vs. Q1) increased the total mortality risk in both men and women by 31% and 36%, respectively.

The authors point out several mechanisms by which meat may be related to death. Specifically for cancer, meat is a source of carcinogens that are formed during high-temperature cooking. Iron in red meat may increase oxidative damage. Meat is also a major source of saturated fat, which has been positively associated with breast cancer and colorectal cancer [3-4].

Regardless of the specific mechanism(s), this research provides new evidence that people should follow long-standing recommendations to minimize consumption of red meat. The Healthy Eating Pyramid, created by the Department of Nutrition at Harvard School of Public Health, is a food pyramid based on the latest science [5]. The Healthy Eating Pyramid recommends using red meat sparingly and suggests switching to fish, chicken or beans several times a week.

Additional nutrition resources are listed in the Highlight HEALTH Web Directory.

References

  1. Sinha et al. Meat intake and mortality: a prospective study of over half a million people. Arch Intern Med. 2009 Mar 23;169(6):562-71. DOI: 10.1001/archinternmed.2009.6
    View abstract
  2. Cross et al. A prospective study of red and processed meat intake in relation to cancer risk. PLoS Med. 2007 Dec;4(12):e325.
    View abstract
  3. Thiebaut et al. Dietary fat and postmenopausal invasive breast cancer in the National Institutes of Health-AARP Diet and Health Study cohort. J Natl Cancer Inst. 2007 Mar 21;99(6):451-62.
    View abstract
  4. The World Cancer Research Fund/American Institute for Cancer Research. Food, Nutrition, Physical Activity, and the Prevention of Cancer: A Global Perspective. Washington, DC: AICR; 2007.
  5. The Nutrition Source – Harvard School of Public Health. Accessed 2009 Mar 26.