Roland L. Phillips

Cohort study of diet, lifestyle, and prostate cancer in Adventist men.

Dietary and lifestyle characteristics were evaluated in relation to subsequent prostatic cancer risk in a cohort of approximately 14,000 Seventh‐day Adventist men who completed a detailed lifestyle questionnaire in 1976 and who were monitored for cancer incidence until the end of 1982. During the 6‐year follow‐up period, 180 histologically confirmed prostatic cancers were detected among some 78,000 man‐years of follow‐up. Increasing educational attainment was associated with significantly decreased risk of prostate cancer in this study; age at first marriage was also inversely associated with risk, although this was not significant. There was no relationship between body mass index (as measured by Quetelets Index) and risk. A history of prostate “trouble” was associated with a 60% increase in risk which was highly significant. Although there were suggestive relationships between increasing animal product consumption and increased risk, these results did not persist after accounting for the influence of fruit and vegetable consumption. Nor was exposure to the vegetarian lifestyle during the childhood years associated with alterations in subsequent risk. However, increasing consumption of beans, lentils and peas, tomatoes, raisin, dates, and other dried fruit were all associated with significantly decreased prostate cancer risk.

Is early natural menopause a biologic marker of health and aging

The relation between age at natural menopause and all-cause mortality was investigated in a sample of 5,287 White women, ages 55 to 100 years, naturally-postmenopausal, Seventh-day Adventists who had completed mailed questionnaires in 1976. The age-adjusted odds ratio of death during 1976-82 in women with natural menopause before age 40 was 1.95 (95% confidence interval = 1.24, 3.07), compared to the reference group of women reporting natural menopause at ages 50 to 54. Corresponding odds ratios of death were 1.39 (95% CI = 1.06, 1.81) for natural menopause at ages 40 to 44, and 1.03 (95% CI = 0.84, 1.25) for natural menopause at ages 45 to 49. Among 3,166 White, 55- to 100-year-old, surgically-postmenopausal, Adventist women, there was no relation between age at surgical menopause and mortality. Logistic regression analyses indicated that findings from this study were apparently not due to confounding by smoking, over- or underweight, reproductive history, or replacement estrogen use.

Dietary habits and past medical history as related to fatal pancreas cancer risk among adventists

Epidemiologic studies of diet and pancreas cancer are few, and include ecologic comparisons and a limited number of prospective and case—control studies. Foods and/or nutrients that have been suggested to be associated with increased risk of this cancer include total fat intake, eggs, animal protein, sugar, meat, coffee and butter. Consumption of raw fruits and vegetables has been consistently associated with decreased risk. Dietary habits and medical history variables were evaluated in a prospective study of fatal pancreas cancer among 34,000 California Seventh‐day Adventists between 1976 and 1983. Forty deaths from pancreas cancer occurred during the follow‐up period. Compared to all US whites, Adventists experienced decreased risk from pancreas cancer death (standardized mortality ratio [SMR] = 72 for men; 90 for women), which was not statistically significant. Although there was a suggestive relationship between increasing meat, egg, and coffee consumption and increased pancreatic cancer risk, these variables were not significantly related to risk after controlling for cigarette smoking. However, increasing consumption of vegetarian protein products, beans, lentils, and peas as well as dried fruit was associated with highly significant protective relationships to pancreas cancer risk. A prior history of diabetes was associated with increased risk of subsequent fatal pancreas cancer, as was a history of surgery for peptic or duodenal ulcer. A history of tonsillectomy was associated with a slight, nonsignificant protective relationship as was history of various allergic reactions. These findings suggest that the protective relationships associated with frequent consumption of vegetables and fruits high in protease‐inhibitor content are more important than any increase in pancreas cancer risk attendent on frequent consumption of meat or other animal products. Furthermore, the previously reported positive associations between diabetes and abdominal surgery and pancreas cancer risk are supported in these data.

Does a vegetarian diet reduce the occurrence of diabetes

We propose the hypothesis that a vegetarian diet reduces the risk of developing diabetes. Findings that have generated this hypothesis are from a population of 25,698 adult White Seventh-day Adventists identified in 1960. During 21 years of follow-up, the risk of diabetes as an underlying cause of death in Adventists was approximately one-half the risk for all US Whites. Within the male Adventist population, vegetarians had a substantially lower risk than non-vegetarians of diabetes as an underlying or contributing cause of death. Within both the male and female Adventist populations, the prevalence of self-reported diabetes also was lower in vegetarians than in non-vegetarians. The associations observed between diabetes and meat consumption were apparently not due to confounding by over- or under-weight, other selected dietary factors, or physical activity. All of the associations between meat consumption and diabetes were stronger in males than in females.

Meat consumption and fatal ischemic heart disease

In 1960 the meat-consumption habits of 25,153 California Seventh-Day Adventists were assessed by questionnaire. Between 1960 and 1980 ischemic heart disease deaths were identified. Meat consumption was positively associated with fatal ischemic heart disease in both men and women. This association was apparently not due to confounding by eggs, dairy products, obesity, marital status, or cigarette smoking. The positive association between meat consumption and fatal ischemic heart disease was stronger in men than in women and, overall, strongest in young men. For 45- to 64-year-old men, there was approximately a threefold difference in risk between men who ate meat daily and those who did not eat meat. This is the first study to clearly show a dose-response relationship between meat consumption and ischemic heart disease risk.

Dietary habits and breast cancer incidence among seventh-day adventists

Breast cancer incidence was monitored in a cohort of 20,341 California Seventh‐day Adventist women who completed a detailed lifestyle questionnaire in 1976, and who were followed for 6 years. There were 215 histologically confirmed primary breast cancer detected among some 115,000 person‐years of follow‐up. Mean age at diagnosis was 66 years, indicating a primarily postmenopausal case series. Established risk factors for breast cancer showed strong relationships to risk in these data. Age at first live birth, maternal history of breast cancer, age at menopause, educational attainment, and obesity were all significantly related to risk. However, increasing consumption of high fat animal products was not associated with increased risk of breast cancer in a consistent fashion. Nor were childhood and early teenage dietary habits (vegetarian versus nonvegetarian) related to subsequent, adult risk of developing breast cancer. Also, a derived index of percent of calories from animal fat in the adult years was not significantly related to risk. These results persisted after simultaneously controlling for other, potentially confounding variables, utilizing Cox proportional hazard regression models.

Coronary heart disease mortality among Seventh-Day Adventists with differing dietary habits: a preliminary report

Seventh-Day Adventists (SDAs) are a conservative religious denomination who abstain from tobacco and alcohol; approximately one-half follow a lacto-ovo-vegetarian diet. In this 6-year prospective study of 24,044 California SDAs age 35 and over, coronary heart disease (CHD) mortality rates for ages 35 to 64 and 65+ are 28% and 50% respectively, of the rates for the same age groups of the total California population. This reduced risk of CHD mortality among SDAs is partially due to abstinence from smoking; however, at least half the low risk among SDAs is likely attributable to other characteristics of the SDA lifestyle. The risk of fatal CHD among nonvegetarian SDA males, ages 35 to 64, is three times greater than vegetarian SDA males of comparable age (P less than 0.01), suggesting that the SDA diet may account for a large share of their low risk. This differential was much smaller for older SDA males and SDA females. Although the differential in risk of fatal CHD for male nonvegetarians versus vegetarians may be partially accounted for by other CHD risk factors, which are more frequent among nonvegetarians, a significant differential persists after adjustment for each of six other CHD risk factors.

Chronic disease among seventh‐day adventists, a low‐risk group. Rationale, methodology, and description of the population

The Adventist Health Study is a prospective cohort study of 34,198 non‐Hispanic white Seventh‐day Adventists (13,857 men; 20,341 women, age 25–100 years) followed for 6 years (1977–1982). Within this population, 55.2% were lacto‐ovovegetarian (consumed meat, poultry, or fish less than one time per week with no restrictions as to egg or dairy product consumption) in 1976 and most abstained from alcohol, tobacco, and pork products. Baseline data included demographic variables, information on current and past dietary habits, exercise patterns, use of prescription drugs, use of alcohol and tobacco, measures of religiosity, occupation and residential histories, anthropometric data, and menstrual and reproductive histories. Nonfatal case ascertainment was completed through review of self‐reported hospitalizations obtained from annual self‐administered mailed questionnaires and through computerized record linkage with two California population‐based tumor registries. Fatal case ascertainment was completed via record linkage with computerized California state death certificate files, the National Death Index, and individual follow‐up. During the 6 years of follow‐up, 52.8% of the 34,198 study subjects reported at least one hospitalization. A total of 20,702 medical charts were reviewed for cancer and cardiovascular disease incidence and 1406 incident cancer cases and 2716 deaths from all causes were identified after baseline data collection.

Prospective study of exogenous hormone use and breast cancer in seventh‐day adventists

Exogenous hormone use as either oral contraceptives (OC) or hormone replacement therapy (HRT) was evaluated in reference to subsequent breast cancer risk in a cohort study of 20,341 Seventh‐day Adventist women, residing in California, who completed a detailed lifestyle questionnaire in 1976 and who were followed for 6 years. During the follow‐up period, 215 histologically confirmed primary breast cancers were detected in the cohort. The mean age at diagnosis was 66 years, indicating a primarily postmenopausal case series. In this cohort, after taking into account potentially confounding variables, current use of HRT (in 1976) was associated with a 69% increase in breast cancer risk, which was statistically significant (RR = 1.69; CI = 1.12–2.55). However, there was no strong increase in risk with increasing duration of use of HRT. Subgroups of women who did experience HRT associated increases in breast cancer risk included those women who had ever used HRT (RR = 1.39; CI = 1.00–1.94) and those with no history of maternal breast cancer (RR = 1.45), those women with prior benign breast disease (RR = 2.80), and those women who experienced menopause at 44 years of age or later (RR = 1.56). There was no substantial increase in breast cancer risk associated with use of OC in this population, although among women with exposure to both OC and HRT there was a suggested increase in risk (RR = 1.42; CI = 0.71–2.85).

Seventh-day Adventist vegetarians have a quiescent proliferative activity in colonic mucosa

The proliferation of epithelial cells in colonic mucosa was studied in humans at varying degrees of risk for colon cancer. Seventh-Day Adventist vegetarians, known to have significantly lower mortality from colon cancer than the general U.S. population, had the most quiescent proliferative activity of mucosal epithelial cells. Increased replication and expansion of the proliferative compartment accompanied increased colon cancer risk. The analytical methods of this study may be useful in assessing the influence of dietary components involved in the initiation, promotion or inhibition of colon cancer, and in developing strategies for nutritional intervention.