The first major study of Adventists, commenced in 1958 at Loma Linda University, has become known as the Adventist Mortality Study. This cohort study of 22,940 California-based Adventists entailed an intensive, 5-year follow-up and a more informal, 25-year follow-up. During the first period, a similar study was being conducted by the American Cancer Society.
Study Group Similarities
Both studies enrolled volunteer subjects who were relatively well-educated. Although the Adventist population in California tended to be more educated than the general public, the American Cancer Society population was, on average, slightly more educated than their Adventist counterparts.
The similarities between the groups are important, because individuals who volunteer for such studies tend to be healthier than the general population and those in the upper socio-economic classes tend to have lower rates of disease overall. Thus, the Adventist Mortality Study and the American Cancer Society Study provide a reasonably fair comparison between Adventists and non-Adventists. Before detailing the results of the comparison between the two groups, we need to define probability values (“p values”).
P values are quoted when they are statistically significant (p<0.05). Note: The p value should not be used to prove or disprove causality. However, in a relative sense: The larger the p value, the more plausible a chance explanation becomes for the apparent association. Conversely, a very small p value provides some evidence in favor of causality.
- When comparing Adventists to their American Cancer Society counterparts, overall cancer mortality was 60 percent for Adventist men and 76 percent for Adventist women.
- When comparing specific types of cancer deaths with the non-Adventist population as the standard:
- Lung cancer deaths among Adventists were 79 percent lower.
- Colo-rectal cancer deaths were 38 percent lower among Adventists.
- Breast cancer death rates for Adventist women were 15 percent lower.
- Prostate cancer death rates for Adventist men were 8 percent lower.
- For lymphoma or leukemia, the death rates were 14 percent lower for Adventist men. For women, the rates were the same.
- Death from coronary heart disease among Adventist men was 34 percent lower; for Adventist women, it was two percent lower. Stroke deaths for Adventist men were 28 percent lower compared to their non-Adventist counterparts. For Adventist women, death from stroke was 18 percent lower.
- Comparing all causes of death among the two populations, Adventist men had a 34 percent lower death rate. Adventist women had a 12 percent lower death rate.
Smoking as a Mortality Rate Factor
Since smoking has been shown to be a major factor in causing diseases such as cancer, researchers from the Adventist Mortality Study compared the mortality rates of non-smokers from both populations. As would be expected, the mortality rates for these non-Adventists were closer to those of the Adventists. However, an advantage for the Adventists persisted which could not be accounted for by differences in tobacco use. Thus, other characteristics of Adventists — such as diet and perhaps social support — are also clearly important in reducing the risk of disease.
Cancer Rates Compared to Non-Smoking, Non-Adventists
- Overall cancer mortality among Adventists was 85 percent for men and 78 percent for women.
- Lung cancer mortality was 67 percent for Adventist men and 42 percent for Adventist women.
- Colo-rectal cancer mortality was 67 percent for Adventist men and 42 percent for Adventist women.
- Breast cancer mortality was 81 percent for Adventist women; prostate cancer death rates were 93 percent for Adventist men.
- Lymphoma and leukemia mortality was 93 percent for Adventist men and 89 percent for Adventist women.
Other Death Rates
Comparing death rates from coronary heart disease between non-smoking Adventists and non-Adventists, Adventist men had a death rate of 24 percent lower than non-Adventist men. Stroke mortality was 25 percent lower in Adventist men and 21 percent lower in Adventist women.
For all causes of death, the rates among Adventist men were 21 percent lower; for Adventist women, nine percent lower compared to non-smoking non-Adventists.
Studies of Adventist mortality rates have also been conducted in other parts of the world.
In 1960, the national census in Norway showed an existing population of 7,173 known Adventist nationals. Following this, Drs. Hans Waaler, Peter Hjort and Vinjar Fønnebø were able to use other Norwegian government statistics to track the mortality of Adventists compared to the general population. The latest reports include follow-up to 1986.
- Adventist men were at 82 percent of the expected death rates for the general population; Adventist women were at 95 percent.
- For deaths due to cardiovascular disease in individuals less than 75 years of age, the rates for Adventist men stood at 65 percent of expectation, and Adventist women at 90 percent.
- Cancer deaths for Adventist men were at 78 percent and at 94 percent of expectation for Adventist women.
Another study looked at the mortality of Dutch Adventists from 1968 to 1977, using records from the church administrative offices. At that time, there were roughly 4,000 church members in Holland. Using the general population of the country to find expected death rates, Drs. Hans Berkel and F. deWaard then compared these to the Adventist population data.
- Compared to the total expected death rate, Dutch Adventists were at 45 percent.
- Cancer deaths were at 50 percent of expectations. Deaths from cardiovascular diseases for Adventists were at 41 percent.
- Breast cancer was at 50 percent; lung cancer at 45 percent; colo-rectal cancer at 43 percent; and stomach cancer at 59 percent.
- Specifically for ischemic heart disease, the rate was 43 percent; for stroke, the rate was 54 percent.
Although it has not yet been mentioned, most of these results are statistically significant, making it unlikely that the differences observed were due to random factors or mere chance.
International Studies Conclusion
According to these studies, evidence points to the Adventist lifestyle providing some protection from cancer and other fatal diseases. However, the Adventist Mortality Study, as well as the studies in Norway, Holland, and others in Poland, Denmark, and Japan, did have a fundamental weakness: Nonfatal events for various diseases were not measured.
The Adventist Mortality Study raised a number of interesting questions. What was it about the Adventist lifestyle that enabled Adventists to live longer? Would lifestyle differences among Adventists themselves produce different risks for contracting specific diseases-both fatal and nonfatal?