Meat-eating and mortality

Nutrition Research Newsletter, Sept, 1994

The diets and lifestyles of vegetarians differ from those of nonvegetarians in many important ways. Several aspects of a vegetarian diet are believed to protect against cardiovascular disease, and some epidemio-logical studies have reported reduced mortality in vegetarians. In the prospective study summarized here, conducted in the United Kingdom, the researchers compared mortality rates in large populations of vegetarians and nonvegetarian controls.

A total of 6,115 non-meat eaters, identified through the Vegetarian Society of the United Kingdom and the news media, and 5,015 of their meat-eating friends and relatives participated in this study. The researchers chose this unusual method of control selection in an effort to find comparison subjects similar to the vegetarians in socioeconomic status and lifestyle factors. During up to 12 years of follow-up, 404 subjects died, including 94 who died of ischemic heart disease and 164 who died of cancer.

As compared to values for the general population of England and Wales, the standardized mortality ratios were 51 (95% CI 38-66) for the meat eaters and 28 (95% CI 20-38) for the vegetarians in this study. In comparison with meat eaters, vegetarians had significantly lower standardized mortality ratios for all causes, ischemic heart disease, and cancer. After adjustment for other lifestyle factors (smoking, body mass index, and social class), the difference in ischemic heart disease death rates between vegetarians and meat eaters became non-significant, but the difference in cancer mortality was essentially unchanged. The effect of diet on all-cause mortality was reduced after this adjustment but remained statistically significant.

The authors conclude, "Our data do not provide justification for encouraging meat eaters to change to a vegetarian diet....There are several attributes of a vegetarian diet apart from not eating meat which might reduce the risk....Current recommendations in most Western countries advise people to adopt many of the attributes of a vegetarian diet, but do not advise excluding meat. This advice seems appropriate in the light of our results."

[Editor's note: This study has an accompanying editorial which discusses several aspects of the study design, including the unusual method of control selection and the types of statistical adjustment used in the data analysis.]

Margaret Thorogood, Jim Mann, Paul Appleby, and Klim McPherson, Risk of Death from Cancer and Ischaemic Heart Disease in Meat and Non-meat Eaters, BMJ 308(6945):1667-1670 (25 June 1994) [Correspondence: Professor Jim Mann, Department of Human Nutrition, University of Otago, PO Box 56, Dunedin, New Zealand]

Additional reading

The Role of Meat in the Human Diet [Symposium Proceedings], Proceedings of the Nutrition Society 53(2):263-333 (July 1994)

* Meat and Right: The Ethical Dilemma, AJF Webster, pp 263-270

* Social Aspects of Meat Eating, Nick Fiddes, pp 271-280

* UK Consumer Perceptions of Meat, NJ Richardson, pp 281-287

* Vitamin E and Meat Quality, Patrick A Morrissey et al, pp 289-295

* Nutritional Implications of a Meatless Diet, TAB Sanders and Sheela Reddy, pp 297-307

* Microbial Hazards in Animal Products, Robert H Madden, pp 309-316

* Nutritional and Other Implications of Irradiating Meat, MH Stevenson, 317-325

* The Role of Nutrients in Meat Flavour Formation, Linda J Farmer, pp 327-333

Cardiovascular Disease Risk Factors: New Areas for Research, Report of a WHO Scientific Group. The report identifies ten promising new areas for further study. The "classical" risk factors, such as high serum cholesterol levels, hypertension, and smoking, are not considered. Subjects covered include plant foods and antioxidants, metabolic factors, hemostatic factors, and hormone replacement therapy. The report (WHO Technical Report Series 841) is available in English, with French and Spanish editions in preparation. It is available for Sw. fr. 10.00 from the World Health Organization, Distribution and Sales, 1211 Geneva 27, Switzerland. In the US it may be ordered for $9.00 (plus $3 for postage and handling) from WHO Publications Center USA, 49 Sheridan Avenue, Albany NY 12210.

The New Food Label: Scouting for Sodium and Other Nutrients Important to Blood Pressure, Paula Kurtzweil, FDA Consumer 28(7):17-21 (Sept 1994) [Correspondence: Paula Kurtzweil, FDA Consumer, FDA (HF1-40), 5600 Fishers Lane, Rockville MD 20857]

Peter WF Wilson, Established Risk Factors and Coronary Artery Disease: The Framingham Study, Peter WF Wilson, American J Hypertension 7(7 Part 2, Supplement): 7S-12S (July 1994) [Reprints: PWF Wilson, MD, Framingham Heart Study, 5 Thurber Street, Framingham MA 01701]