We combined data from 5 prospective studies to compare the death rates from common diseases of vegetarians with those of nonvegetarians with similar lifestyles. A summary of these results was reported previously; we report here more details of the findings. Data for 76172 men and women were available. Vegetarians were those who did not eat any meat or fish (n = 27808). Death rate ratios at ages 16-89 y were calculated by Poisson regression and all results were adjusted for age, sex, and smoking status. A random-effects model was used to calculate pooled estimates of effect for all studies combined. There were 8330 deaths after a mean of 10.6 y of follow-up. Mortality from ischemic heart disease was 24% lower in vegetarians than in nonvegetarians (death rate ratio: 0.76; 95% CI: 0.62, 0.94; P<0.01). The lower mortality from ischemic heart disease among vegetarians was greater at younger ages and was restricted to those who had followed their current diet for >5 y. Further categorization of diets showed that, in comparison with regular meat eaters, mortality from ischemic heart disease was 20% lower in occasional meat eaters, 34% lower in people who ate fish but not meat, 34% lower in lactoovovegetarians, and 26% lower in vegans. There were no significant differences between vegetarians and nonvegetarians in mortality from cerebrovascular disease, stomach cancer, colorectal cancer, lung cancer, breast cancer, prostate cancer, or all other causes combined.

In a matched case-control study of cancer of the lower urinary tract in northern Germany in which 340 male and 91 female case-control pairs were interviewed between 1977 and 1982, cigarette smokers were found to have an odds ratio of 2.3 for males and 2.9 for females compared with nonsmokers. A significant dose-response relation was observed for increasing cigarette consumption, and a significant decrease in risk was shown for ex-smokers. Employment in rubber, plastics, dye, textiles, and mining industries was associated with a higher risk, and increased odds ratios were also observed for exposure to spray painting, coal pitch, chromium, and zinc. Controlling for smoking, an elevated risk of 2.3 for drinking more than four cups of coffee per day and significant odds ratios of 2.1 and 2.8 for a daily consumption of 0.5-1.0 liter and above 1.0 liter of beer, respectively, were noted among men. A highly significant odds ratio of 4.0 was found for a daily fluid intake of more than 2 liters. Dietary habits such as the frequent consumption of canned food and fatty meals were associated with a higher risk, whereas a regular consumption of fruits and vegetables was associated with a lower risk. Fourteen determinants found to be important in this case-control series were analyzed by using multiple logistic regression.

A multicentric hospital-based case-control study was simultaneously performed in a high-risk and a low-risk area for stomach cancer in Germany, 143 patients with incident stomach cancer and 579 controls completing a retrospective interview about life style aspects. Periods of non-centralized water supply or well water as the only source compared to life-long central water supply, and preservation of meat by smoking it with spruce compared to no home smoking of meat, were significantly associated with an increased stomach cancer risk. use of a refrigerator at home for 30 and more years compared to 24 years or less showed an inverse relationship, whereas salt intake estimated by questionnaire showed no relationship to stomach cancer risk. Tobacco smoking was negatively associated with risk for current smokers of cigarettes compared to non-smokers but was presumably not causally related. After adjustment for other food constituents, only increased vitamin C consumption showed an inverse relation to risk. For food groups, increased consumption of fruit, citrus fruit, cheese and whole-meal bread were associated with decreased risk. A similar effect was also seen for increased consumption of raw vegetables. Total vegetable consumption was not particularly associated with risk. Increased consumption of processed meat and of beer showed a positive association with risk whereas increased wine and liquor consumption showed a significant negative association. The association of alcoholic beverages with stomach cancer risk may reflect a particular life style rather than being causally related to risk.