Research findings suggest that the Adventist lifestyle contributes to better and longer life.
by Larry Beeson**
The Epidemiology of Seventh-day Adventists
During the last several decades, health-related organizations within the United States and elsewhere (for example, the National Institutes of Health, the American Cancer Society, the American Heart Association, the U.S. Department of Health and Human Services, the World Health Organization, etc.) have provided epidemiologic evidence from around the world as to which lifestyle characteristics promote health and deter the disease process. Part of that evidence comes from health research on Seventh-day Adventists. Health research has focused on Adventists for two reasons. First, they tend to be more homogeneous in many lifestyle choices, such as avoidance of alcohol and tobacco. Second, they are more heterogeneous in nutritional habits: they range from vegan (no animal products in diet) to lacto-ovo-vegetarians (whose diet includes dairy and egg products, but no meat) to omnivores (meat eaters). More than 250 scientific articles have been published worldwide on the health advantage of Adventists. Most of what is described below refers to research conducted by Loma Linda University scientists on Adventists in California. But similar findings have been reported for Adventists in Norway, Holland, Poland, Denmark, Japan, Australia, and other countries.
The Adventist Mortality Study (AMS)
The first major epidemiologic study of Adventists began in 1958. It is known as the Adventist Mortality Study (AMS), involving 22,940 non-Hispanic white Adventists residing in California.(1) The findings of this study on Adventists were compared with a similar study of non-Adventists conducted by the American Cancer Society during the same time period. Both studies enrolled volunteer subjects in California who were relatively well-educated compared to the average Californian. Both studies obtained copies of death certificates of participants in the study who had died during the subsequent follow-up years. The similarities between the groups were important because it has been found that individuals who volunteer for such studies tend to be healthier than the general population, and those in the upper-economic classes tend to have lower rates of disease overall. Thus, the Adventist Mortality Study, and the American Cancer Society Study provided a reasonably fair comparison between Adventists and non-Adventists.
The comparison revealed the following: If the cancer mortality in the American Cancer Society Study was 100, the mortality for Adventists was 60 for men and 76 for women. This means that after adjusting for differences in age distributions in the two studies, Adventist men had a significantly lower death rate from cancer for a given age group compared to what might be expected for a comparable group. This means Adventist men still died of cancer but at a much older age than the non-Adventist men. The same can be said for Adventist women. Since there is no a priori reason to believe that California Adventists are genetically different than non-Adventists, the hypothesis is that one or more lifestyle characteristics or environmental influences may be responsible for the delay in cancer death.
Since smoking has been shown to be a major factor in causing cancer, researchers from the Adventist Mortality Study compared the mortality rates of nonsmokers from both population. As would be expected, the mortality rates for these non-Adventists were closer to those of the Adventists. However, an advantage for the Adventists generally persisted which could now not be accounted for by differences in past tobacco use. Thus, other characteristics of Adventists, apart from their nonsmoking status, such as diet and perhaps social support, are also clearly important in reducing the risk of disease.
Adventists also appeared to have a delay in cardiovascular deaths. If the death rate from coronary heart disease in the American Cancer Society study is taken as 100 percent, then Adventist men had only 66 percent of what was expected. Adventist women showed only a small reduction, with 98 percent. Adventist men also died of stroke, but their death rate was only 72 percent compared to their non-Adventist counterparts. For Adventist women, their death from stroke was 82 percent of that for the non-Adventists.
Thus, according to these studies, it is quite evident that the Adventist lifestyle does provide some protection from cancer and other fatal diseases. But differences in mortality rates between Adventists and others may be due to at least two scenarios: 1: Adventists may acquire a particular disease at the same rate as others, but survive longer with the disease because of better access to medical care or an improved immune system or better lifestyle; and/or 2: Adventists actually get the disease at a lower incidence rate than non-Adventists. It may be that both these possibilities contribute to the lower mortality rates observed among Adventists. But mortality studies like the AMS could not resolve this issue. The Adventist Mortality Study raised a number of interesting questions. What was it about their lifestyle that enabled Adventists to live longer? Would Adventist lifestyle differences in themselves produce different risks for contracting specific diseases both fatal and nonfatal?
The Adventist Health Study (AHS)
The Adventist Health Study (AHS) is a second major study of California Adventists. Funded by the National Cancer Institute and the National Heart, Lung, and Blood Institute, the study began in 1974 and was conducted by Loma Linda University researchers. The study incorporated the incidence (that is, new cases) of cancer and heart disease in the ever-expanding research on the characteristics of the Adventist lifestyle that enabled Adventists to have a “health advantage.” Similar to the AMS study, death certificates were obtained to document the underlying cause of death for members who died during the study. Hospital records were used for all nonfatal cases. The response rate from white non-Hispanic subjects to the mailed lifestyle questionnaire was the highest of any ethnic group and numbered 34,198. This group became the “incidence study” portion of the AHS (2) in that new cases (incidence) of fatal or nonfatal cancer and myocardial infarction diagnosed after completion of the baseline lifestyle questionnaire were ascertained.
AHS and AMS had some basic difference. For one, AHS was designed to find out which components of the Adventist lifestyle give protection against disease. It has not been a major aim of AHS to compare the incidence rates of disease or mortality between Adventists and non-Adventists. The AHS was primarily designed to look at variations in lifestyle among Adventists themselves and how these variations translated into changes in disease risk.
The AHS also added a more detailed investigation of diet compared to the 1960 American Cancer Society questionnaire used by the AMS. Further, the AHS questionnaire included questions on previous medical history, drug therapy, physical activity, and a variety of psycho-social questions. When the gathering of follow-up data was concluded 32,000 hospitalizations (for any reason) were self-reported representing more than 18,000 different participants. Of the hospitals involved, 698 were in California, and 960 were out-of-state. All these hospitals were contacted in a six-year follow-up of all those who completed the baseline lifestyle questionnaire.
A basic profile of the AHS population showed an average age of 51 years for men and 53 for women. The proportion of subjects who had been diagnosed by a physician as hypertensive was close to that expected for an adult population. Although a modest number of subjects admitted to past cigarette smoking-usually before joining the Adventist Church-there were virtually no current smokers in the population. A relatively large proportion claimed to exercise with at least moderate frequency. The study population, made up of about 60 percent women, tended to be well-educated. A little more than half of the AHS participants said they ate meant less than once a week. Most were lacto-ovo-vegetarians.
What did these studies reveal on the influence of lifestyle on reduction of disease incidences and mortality?
Lung cancer. By far the strongest risk factor for lung cancer is chronic exposure to tobacco smoke, from both active smoking as well as from passive smoking (“secondhand smoking”). Working or living with a smoker has been shown to increase one’s chances of developing cancer of the respiratory tract. The AHS demonstrated(3) that individuals could further reduce their chance of developing lung cancer by not only minimizing exposure to tobacco smoke, but also by incorporating in their diet a variety of fruits, many of which contain components (for example, antioxidant vitamins) thought to enable the body to fight off cancer. Adventists who consumed fruit two or more times a day had only 25 percent chance of developing lung cancer compared to those individuals who consumed fruit less than three times a week. This health advantage of fruit consumption was observed in Adventists who had previously quit smoking as well as Adventists who had never smoked.
Prostate cancer. According to one estimate, (4) 29 percent of all newly diagnosed cancers among U.S. males in 1998 had to do with the prostate gland, and incidence of this disease has been rising during the last several decades. Strong protective relationships were observed(5) in Adventist men who consumed moderate amounts of legumes (such as beans, lentils, peas), fresh citrus fruit, dried fruit (for example, raisins and dates), and tomatoes.
Breast cancer. In the mid-1980s, lung cancer surpassed breast cancer as the most commonly diagnosed cancer in U.S. females .(6) However, in nonsmoking populations, such as the Seventh-day Adventists, breast cancer is still the leading newly diagnosed cancer. The known risk factors for breast cancer include: increased exposure to estrogen and/or progesterone hormones, early menarche, late menopause, and obesity in post-menopausal women. Factors that may be protective of the development of breast cancer include: decreased exposure to estrogen and/or progesterone hormones, early first-term pregnancy, lactation, and physical activity. In the AHS, women who exercised vigorously had a 21 percent decrease in lifetime risk of breast cancer and an average delay of 6.6 years in the age at which this cancer is diagnosed compared to women who infrequently exercised.(7) Physical inactivity had its most important effect on age at diagnosis rather than lifetime risk. The protective effect of physical activity on risk of breast cancer may be particularly pronounced at younger ages as the benefits of exercise was not clearly seen in post-menopausal women.
Bladder cancer. Cigarette smoking is a strong risk factor for bladder cancer. Adventists who had smoked cigarettes prior to joining the Church had more than two-fold increased risk of bladder cancer, compared to those who had never smoked. Previous investigators have noted increased bladder cancer risk in persons with high consumption of animal foods. Approximately 50 percent of the participants in the AHS were lacto-ovo-vegetarians. Adventists who avoided meat, poultry, and fish had less than half the risk of bladder cancer, compared to those who ate these foods three or more times per week. (8)
Pancreas cancer. AHS observed that increasing consumption of legumes, dried fruit, and vegetarian protein products (such as soy, gluten, and nut-based) were associated with highly significant protective relationships to pancreas cancer risk.(9)
Other cancers. The AHS has investigated other cancers (colon cancer,(10) tumors of the brain and cranial meninges, (11) and leukemia and myeloma(12) and has observed that those individuals who follow the “Adventist lifestyle” most closely are those who also enjoy a reduced chance of acquiring any of the chronic diseases investigated.
Heart disease. The AHS not only investigated the relationship between a variety of lifestyle practices and incident and fatal cancers, but also looked at factors that relate to heart disease. A fascinating AHS finding that has been replicated by researchers in other populations was that frequent consumption of nuts five or more times per week (about a handful each time) was associated with substantially fewer definite fatal coronary heart disease events and definite nonfatal myocardial infarctions (heart attacks) compared with those who consumed nuts less than once per week. But since nuts are generally very high in fat, consuming large amounts may not be as beneficial.
Adventists who ate mainly whole wheat bread experienced a 40 percent reduction in risk of heart attack, compared to those who ate mostly white bread. Also, there was more than a doubling of risk of heart attack among men who consumed beef at least three times per week, compared to vegetarians. Adventists who exercised regularly 15 minutes or more at least three times per week experienced a significant reduction in risk of dying of heart attack.
Vegetarian food guide pyramid
Based on the international epidemiologic evidence over the last several decades, which includes results from studies on Adventists, health-related organizations around the world have advocated a dietary lifestyle aimed at reducing the risk of cancer, heart disease and other chronic diseases. The food guide pyramid illustrates the relative contribution of these different food items. At the foundation of the pyramid are the whole-grain breads and cereals. Next are the fruits and vegetables. Many people do not eat enough protective elements such as vitamins. The next level of the pyramid gives the foods that provide protein and minerals. We need fewer servings of these. Finally, at the tip of the pyramid are the sweets, fats, and oils, of which we need very little.
If these recommendations are in fact helpful in reducing chronic disease, then it seems logical that we should observe a reduction of these diseases in a population that has been following these principles for over 100 years. And that is exactly what we find in studies of Seventh-day Adventists.
*Adapted from an article in the [College and University] Dialogue, an international journal of faith, thought and action, vol. 11, no. 2/1999. Reprinted by permission.
**Larry Beeson (Dr. P.H. candidate, Loma Linda University) teaches epidemiology and bio statistics at the school of Public Health and the School of Medicine of Loma Linda University. He has been part of the Adventist Health Study research team since its inception. Postal address: School of Public Health; Loma Linda University; Loma Linda, California 93350; U.S.A.
Notes and references
1. F. R. Lemon and R.T. Walden, “Death From Respiratory System Disease Among Seventh-day Adventist Men,” Journal of American Medical Association 198 (1966) 2: 11-126; F.R. Lemon and J.W. Kuzma, “A Biologic Cost of Smoking: Decreased Life Expectancy,” Archives of Environmental Health 18 (1969): 950-955; R.L. Phillips, F. R. Lemon, W.L. Beeson, and J.W. Kuzma, “Coronary Heart Disease Mortality Among Seventh-day Adventists With Differing Dietary Habits; A Preliminary Report,” American Journal of Clinical Nutrition 31 (1978 Supplement): 191-198; R.L. Phillips, L. Garfinkel, J.W. Kuzma, W.L. Beeson, T. Lotz, and B. Brin, “Mortality Among California Sevneth-day Adventists for Selected Cancer Sites,” Journal of National Cancer Society 65 (980): 1097-1107; R.L. Phillips, J.W. Kuzma, W.L. Beeson, and T. Phillps, J.W. Kuzma, W.L. Beeson, and T. Lotz, “Influence of Selection Versus Lifestyle of Risk of Fatal Cancer and Cardiovascular Disease in Seventh-day Adventists,” American Journal of Epidemiology 112 (1980) 2:296-312.
2. W.L. Beeson, P.K. Mills, R.L. Phillips, M. Address, and G.E. Fraser, “Chronic Disease Among Seventh-day Adventists: A Low-risk Group,” Cancer 64 (1989): 57-81.
3. G.E. Graser, w.L. Beeson, and R.L. Phillips, “Diet and Lung Cancer in California Seventh-day Adventists,” American Journal of Epidemiology 133 (1991):683-93.
4. S.H. Landis, T. Murray, S. Bolden, and P.A. Wingo, “Cancer Statistics, 1998, “Ca-A Cancer Journal for Clinicians 48 (1998) 1:6-29
5. P.K.Mills, W.L. Beeson, R.L. Phillips, and G.E. Fraser, “Cohort Study of Diet, Lifestyle, and Prostate Cancer in Adventist Men,” Cancer 64 (1989) 3:598-604.
6. See 4 above.
7. G.E. Fraser, D. Shavlik, “Risk Factors, Lifetime Risk, and Age at Onset of Breast Cancer,” Annals of Epidemiology 7 (1997):375-382.
8. P.K. Mills, W.L. Beeson, R.L. Phillips, and G.E. Fraser, “Bladder Cancer in a Low Risk Population: Results from the Adventist Health Study,” American Journal of Epidemiology 133 (1991) 3:230-239.
9. P.K. Mills, W.L. Beeson, D.E. Abbey, G.E. Fraser, and R.L. Phillips, “Dietary Habits and Past Medical History as Related to Fatal Pancreas Cancer Risk Among Adventists,” Cancer 61 (1988) 12:2578-2585.
10. P.N. Singh and G.E. Fraser, “Dietary Risk Factors for Colon Cancer in a Low-Risk Population,” American Journal of Epidemiology 148 (1998) 8:761-774
11. P.K. Mills, S. Preston-Martin, J.F. Annegers, W.L. Beeson, R.L. Phillips, GE Fraser, “Risk Factors for Tumors of the Brain and Cranial Meninges in Seventh-day Adventists,” Neuroepidemiology 8
12. P.K. Mills, G.R. Newell, W.L. Beeson, G. E. Fraser, and R.L. Phillips, “History of Cigarette Smoking and Risk of Leukemia and Myeloma: Results from the Adventist Health Study,” Journal of National Cancer Institute, 82 (1990): 1832-1836.
13. G.E. Fraser, J.Sabate, W.L.Beeson, T.M. Strahan, “A Possible Protective Effect of Nut Consumption on Risk of Coronary Heart Disease,” Archives of Internal Medicine, 152 (1992); 1416-1424.