Research on life expectancy for Seventh-day Adventists has long intrigued scientists. The first life table on Seventh-day Adventists was published in the Review and Herald in 1967. 1 It was based on data collected in cooperation with the American Cancer Society's (ACS) study of more than 1 million people. The objective of the ACS study was to determine factors associated with the development of cancer.
Of the 27,514 Seventh-day Adventist respondents included in what later became known as the Adventist Mortality Study, 9,804 were men and 17,710 were women. That research found that 35- year-old Adventist men had a life expectancy 6.2 years longer than their general population neighbors. The difference was attributed to the Adventists' avoidance of smoking.
Significant at the time, the Adventist Mortality Study has continued its unique contribution to science. 2 This lifestyle data collection is probably the only data resource that allows such a long-term look at the life expectancy of vegetarians. And 26 years of follow-up has made the data even more valuable. Numerous questions have arisen over the past two decades: Can the life expectancy figures be independently verified? How do various lifestyle practices influence life expectancy? Do vegetarians have a life expectancy advantage? Is there scientific evidence that practices such as exercise, maintaining ideal weight, or adopting other health practices after joining the Seventh-day Adventist Church make a real difference in life expectancy? In this article, I will demonstrate how the life expectancies of Adventists differ from those of the California population and how the life expectancies differ among various Adventist lifestyle sub groups.
Life table analysis
The life table is one of the oldest statistical methods used to measure mortality and longevity. Insurance companies use this technique to estimate the life expectancy of their policy holders. The California population, though not the ideal comparison group, was the only group with the necessary data to allow a reasonable comparison of life expectancies.
This study compared Adventist life expectancies with those of the California general population, composed of smokers and nonsmokers, drinkers and abstainers, and persons with all varieties of eating patterns. The life expectancy comparisons for men are shown in Figure 1 and for women in Figure 2. From these figures it is evident that Adventist men and women have a life expectancy that is substantially greater than their fellow Californians. Specifically, the average life expectancy of a 35-year-old Adventist male is 47.0 years, an 8.9-year advantage over the California male. The corresponding difference for a 35-year-old female is 7.5 years. These differences are higher than those reported in 1967.
The larger differences in life expectancy between Adventists and Californians cited in comparison with the 1967 report are likely explained by a number of factors. One of these factors is the avail ability of more reliable data (26 years rather than 3 years of follow-up). Another possible reason for the larger differences is that the life expectancy of Californians is low because it was computed on the entire California population including both healthy and sick individuals, whereas the life expectancy of the Adventist population was high because it was computed only on a portion of the population, namely those who completed the American Cancer Society questionnaire. In view of this, these differences between Adventists and Californians are provided here as general background information. The most significant comparisons are those made among the Adventist subgroups.
One interesting finding of this research is that Adventist men have a life expectancy exceeding that of California women. This is a notable accomplishment since U.S. women have, for more than a century, outlived U.S. men. The differences in life expectancy between Adventist women and California women are smaller than for men, possibly because of the greater impact of smoking in men since the proportion of smokers and ex-smokers is higher in men than in women. No doubt there are other reasons, as yet unverified, why women have a preferential life expectancy over men.
A life expectancy difference of 8.9 years for a 35-year-old Adventist male represents the average for a typical Adventist man. This means that some males will live longer, and some not as long. Nine extra years, as compared to a typical working life of about 40 years, is a considerable period.
It is interesting to compare life tables for Adventist vegetarians and nonvegetarians, various exercise and weight groups, and other groups. Marital status and education must also be taken into account since both have an impact on life expectancy.
It should be noted that being a vegetarian means more than simply not eating meat. Persons adopting a vegetarian life style typically eat fewer junk foods, are less likely to be overweight or drink coffee, and often are better educated than nonvegetarians. Among Adventists, they also attend church more frequently than nonvegetarians. Comparing vegetarians (those who ate no meat or who ate it less than once a month) to nonvegetarians, we found that 40-year-old male vegetarians outlived nonvegetarians by 3.7 years (see Table 1). The differences became smaller with advancing age. The added life expectancy of vegetarian women ranged from only 1.1 3 years at age 40 to 0.2 years at age 80. Life expectancy between men who exercised heavily and those who exercised little or not at all ranged from 2.6 to 5.0 years for the various age categories. The beneficial effects of exercise on life expectancy in women were undeterminable because no exercise data were gathered from them.
Since there were hardly any Adventists who smoked, the study was not able to contrast the differences in life expectancy between smokers and nonsmokers. However, the surgeon general reports that a male nonsmoker will live about eight years longer than one who smokes 40 or more cigarettes per day. 4 From an analysis not shown here, it has been learned that the difference in life expectancy between Adventist never-smokers and ex-smokers is quite small. This suggests that there are clear-cut benefits to quitting.
Life expectancies of men with normal weight, as compared to men who were overweight by 20 percent or more, ranged from an advantage of 1.9 years at age 45 to 0.3 years at age 80. For those 80 and older, overweight men had a small advantage over those of a normal weight. Similar differences in life expectancy were seen for women up to age 74. After that age, women 20 percent or more overweight had a 0.8-year life expectancy advantage over those of normal weight. Though we have not found a definite reason for the reversal of risk at higher ages, a possible explanation is that since the risk of death among those who are overweight is higher than among those with normal weight, the less hardy overweight individuals die earlier, leaving only particularly hardy individuals alive past 80.
To facilitate more appropriate comparisons between the vegetarians and nonvegetarians, Table 2 shows the life expectancies for specific subgroups. This takes into account other factors affecting life expectancy. The results show that the life expectancies of vegetarian men are higher than for nonvegetarian men by 2.0 to 7.7 years when marital status and education are taken into account. The opposite was observed for women: married, college-educated, nonvegetarian women had a life expectancy advantage over vegetarian women. This reversal, however, was not observed among the high-school educated, married women, nor among the subgroups of not married women regardless of their education level. There is currently no plausible explanation for this result.
It is worth noting that the Adventist population subgroup with the lowest life expectancy (the nonmarried, nonvegetarian person, with a high school education or less) still has a life expectancy higher than the general California population by about three years for men and five years for women.
This would suggest that the Adventist life expectancy advantage cannot be entirely explained by the Adventists' higher marital status and higher educational attainments, but more likely by the adoption of their health practices and other factors.
How to stay healthy
Several research reports support the concept that personal health practices (lifestyle) profoundly affect one's health. One of the landmark studies in the area of health practices and mortality was conducted by Belloc and Breslow at the Human Population Laboratory.5 In a 12- year follow-up study of nearly 7,000 individuals, Drs. Lester Breslow and James Emstrom6 examined such health practices as not smoking, exercising, little or no drinking, eating breakfast, not snacking, not being overweight, and sleeping seven to nine hours per day, and their relationship to death. They reported that men who followed three or fewer of these seven favorable health practices had a mortality rate that was nearly four times higher than that of men who followed all seven. For women the comparable rate was more than twice as high. Such scientific investigations have identified those practices that promote health, vitality, and longevity, and now provide scientific support for those who originally adopted these practices by faith alone.
The higher Adventist life expectancy is not unique to California. Three European studies of Adventists, based on smaller samples, show an Adventist life expectancy advantage over their corresponding countrymen, with more of an increase for men than for women. Hans Berkel, in his study of 522 Adventist Dutch fatalities, reported an 8.9-year life expectancy advantage for men and a 3.7- year edge for women. 7 Waaler and Hjort, who studied 9,336 Norwegian Adventists, reported a 4.2-year advantage for men and a 1.9-year advantage for women.8 In a study of 236 Adventists from one church in southern Poland, Dr. W. Jedrychowski observed 35 deaths and reported a 9.5-year mean age advantage at death for Adventist men and 4- 5-year age advantage for women. 9
These findings bring scientific evidence that suggests that a measurably longer life expectancy results not only from abstaining from smoking, but also from adopting a healthy vegetarian diet, getting adequate exercise, and maintaining normal weight. These findings support the importance of the Adventist Church's 125-year commitment to the adoption of good health practices. The benefit gained from these health practices and the example set will depend, to a large degree, on how seriously the principles are followed. This is primarily an individual decision, not one that can be made by anyone else.
Furthermore, those who attain a higher educational status also have a life expectancy advantage. Why the differences are lower for women than men is not clear. Perhaps valuable information is yet to be obtained from the ongoing Adventist Health Study.
In general, the gains in life expectancy during the past 60 years are primarily because of improvements in health care in infancy and childhood. The increase in life expectancy at age 35 has been relatively small. The introduction of antibiotics, improved medical knowledge, and better surgical techniques accounts for this small gain. But none of these efforts has even come close to the effects of a good lifestyle.
Dr. T. Abelin of Harvard University noted that such an increase in life expectancy as the one observed by these adults exceeded all the gains in life expectancy made in the previous 40 years in this country, including all the advances in medical skills and knowledge, plus in numerable improvements in man's environment. 10
The Adventist advantage
Over the years more than 150 articles in scientific journals have reported on various aspects of Adventist health. Most of these have verified the benefits of the Adventist lifestyle.
These research papers have had an important impact both on individuals and government officials. After a presentation by the late Dr. Roland Phil lips, one scientist commented, "It appears that the best insurance that one can take out today is to follow the life style of Adventists." In 1980, Sidney Katz, a Canadian official, reviewed the data on the benefits of the Adventist lifestyle. He said, "I've got some advice on how to improve the health of Canadians and, at the same time, lop billions of dollars off our annual health costs. I think we should study the lifestyle of adherents of the Seventh-day Adventist Church and then explore ways and means of persuading the public to emu late the Adventists in at least some ways." 11 And when the U.S. Congress was adopting dietary guidelines for the nation, the Senate Select Committee utilized findings on Adventists, among others, to come up with the guidelines.
Many scientists, when discussing the results of Adventist studies, refer to the beneficial effects of the Adventist life style as the "Adventist advantage." As government planners explore the implications of a longer life span, they are interested in considering what is likely to happen as an ever-increasing number of people adopt a more beneficial lifestyle. It is for this reason that many scientists view the Adventist advantage as "a peek into the future" of what the U. S. population is likely to experience as more people adopt a healthier lifestyle. Adventists' reputation for extended longevity presents us with special opportunities to share our knowledge about these benefits with others who are interested in living longer and better.
In summary, the higher life expectancies observed in this analysis support the previously reported findings. In 1969 it appeared that the bulk of the life expectancy advantage was attributable to not smoking. Now the results suggest that other lifestyle factors also contribute to life expectancy. Lifestyle choices seem to have more influence on life expectancy than does the long-term improvement in health care. How satisfying it is to see so many individuals in the general public discovering the benefits of a regular fitness program, refusing to smoke, being more concerned with what they eat and drink, and how they can best maintain a normal weight level. No wonder the U.S. heart disease mortality rates have been falling for the past few years. Many of these healthy-life devotees have discovered that one's lifestyle choices transcend historical trends in their influence on life expectancy.
The payoff for making such personal choices was clearly voiced by King Solomon, who said, "My son, forget not my law; but let thine heart keep my commandments; for length of days, and long life, and peace shall they add to thee" (Prov. 3:1, 2).
1 F. R. Lemon and J. W. Kuzma, "The Life
Expectancy of Seventh-day Adventists," Review
and Herald, Dec. 14, 1967.
2 There are two long-term studies that have
looked at the lifestyle of Seventh-day Adventists.
This report is based on results from the Adventist
Mortality Study. The other study is the more recent
Adventist Health Study, which is currently devel
oping reports. As with most scientific research,
new data may modify the conclusions made in ear
3 Differences of 1.0 or more years are statistically
significant at p. 0.05.
4 U.S. Department of Health, Education, and
Welfare, Public Health Service, Smoking and
Health, DHEW Pub. No. (PHS) 79-50066, Part I,
5 N. B. Belloc, L. Breslow, and]. R. Hochstim,
"Measurement of Physical Health in a General
Population Survey," American Journal of Epidemiology
93 (1971): 328-336.
6 L. Breslow and]. E. Enstrorn, "Persistence of
Health Habits and Their Relationship to Mortal
ity," Preventive Medicine 9 (1980): 469-483.
7 J. Berkel and F. deWaard, "Mortality Pattern
and Life Expectancy of Seventh-day Adventists in
the Netherlands," International Journal ofEpidemiology 12 (1983): 455-459.
8 H. WaalerandP. F. Hjort, "Hoyere levealder
hos Norske Adventister 1960-1977: Et budskap om
livstil og helse?" Tedsskr Nor Laegeforen 101
(1981): 623-627. (English translation: "Low
Mortality Among Norwegian Seventh-day Adventists
1960-1977: A Message on Lifestyle and Health?")
9 W. Jedrychowski, B. Tobiasz-Adamczyk, A.
Olma, and P. Gradzikiewicz, "Survival Rates
Among Seventh-day Adventists Compared With
the General Population in Poland," Scandinavian
Journal of Socialized Medicine 13 (1985): 49-52; also
see H. J. Stanton, A Global Review of Adventist
Health Research (DHS dissertation, Loma Linda
10 T. Abelin, "Application of Life Table Methods
to Results of Epidemiologic Follow-up Studies
on Smoking and Mortality," American journal of
Epidemiology 81 (March 1965): 254-269.
11 S. Katz, in Maclean's Magazine, May 5, 1980.