Cohort study of tofu intake and prostate cancer: no apparent associationNomura AM, Hankin JH, Lee J, Stemmermann GN
Three case-control studies and one cohort study have suggested that soy products reduce the risk of prostate cancer (1-4), but overall evidence from these epidemiologic studies is still limited. To investigate this issue further, we conducted a cohort study on the association of tofu (soybean curd) intake with prostate cancer among Japanese Americans in Hawaii. The annual mortality rate of prostate cancer among Japanese American men is 11.7 per 100,000, which is lower than the mortality rate of 24.1 per 100,000 among U.S. Whites (5). However, unlike clinical prostate cancer, occult prostate cancer, as determined by step sections of the prostate at autopsy, is as common among the Japanese Americans in Hawaii as among the U.S. Whites (6). This suggests the operation of factors that inhibits the progression of this tumor after induction among Japanese American men.
Cancer Epidemiol Biomarkers Prev. 2004 Dec;13(12):2277-9. PMID: 15598793
A prospective study of colon and rectal cancer among Hawaii Japanese menChyou PH, Nomura AM, Stemmermann GN
The goals of this study were to assess the association of diet, alcohol, smoking, and other life-style factors with the risk of colon and rectal cancer and to examine the differences in the risk factors associated with each cancer site. Information on diet, alcohol, smoking, and other life-style factors was obtained from 7945 Japanese-American men who were living in Hawaii and examined from 1965 through 1968. After 174,514 person-years of observation, 330 incident cases of colon cancer and 123 incident cases of rectal cancer were diagnosed by histology. The risk of both colon and rectal cancer increased with age, alcohol intake, and pack-years of cigarette smoking. For colon cancer, there was also a direct association with body mass index and heart rate, while an inverse association was observed with serum cholesterol, intake of monounsaturated fatty acid, and percentage of calories from fat. For rectal cancer, the risk decreased with an increase in the intake of carbohydrates as percentage of calories. These findings suggest that some of the risk factors for colon cancer are different from those for rectal cancer.
Annals of Epidemiology. 1996 Jul;6(4):276-82. PMID: 8876837
Diet, alcohol, smoking and cancer of the upper aerodigestive tract: a prospective study among Hawaii Japanese menChyou PH, Nomura AM, Stemmermann GN
A cohort study of upper aerodigestive tract cancer was conducted among 7,995 Japanese-American men who were interviewed and examined from 1965 to 1968. Information was collected about smoking history and alcohol and dietary intake. After 24 years, 92 incident cases with histological confirmation of diagnosis were identified. Current cigarette smokers at time of examination had a 3-fold risk for upper aerodigestive tract cancer compared with never-smokers. A dose-response relationship was present with increasing amount and duration of cigarette use. Consumption of beer, wine, spirits and total alcohol was strongly associated with increased risk. Of 23 food and beverage categories, only candy/jelly/soda pop consumption had a statistically significant inverse trend. Frequent consumption of fruit was also inversely associated with this cancer. In contrast, the risk tended to be positively associated with consumption of rice, seaweed, tofu or tsukudani (a mixed dish of fish, sugar, soy sauce and seaweed), but the dose-response relationship was not statistically significant. For nutrient intake, increased calcium and fat intake decreased the risk for this cancer.
Int J Cancer. 1995 Mar 3;60(5):616-21. PMID: 7860134
A prospective study of diet, smoking, and lower urinary tract cancerChyou PH, Nomura AM, Stemmermann GN
The association of diet and smoking with bladder cancer was investigated in a cohort study conducted in Hawaii. The study included 7995 Japanese-American men who were born between 1900 and 1919, and were examined from 1965 to 1968. After 22 years of follow-up, 96 incident cases of bladder cancer were diagnosed. Current cigarette smokers had a 2.9-fold risk of bladder cancer, compared with nonsmokers. A direct dose-response relation was observed, based on pack-years of cigarette smoking. Consumption of fruit was inversely associated with the risk of bladder cancer (P = 0.038). The relative risk was 0.6 among subjects who had the most frequent (> or = 5 times/wk) intake of fruits compared to those with the least intake (< or = 1 time/wk). A weaker inverse association with milk intake was also observed (P = 0.07). Frequent consumption of fried vegetables, pickles, or coffee increased the risk of bladder cancer, but none of these foods showed a significant dose-response relationship. There was no association of other selected foods, alcohol, total calories, protein, fat, or carbohydrates with bladder cancer risk.
Annals of Epidemiology. 1993 May;3(3):211-6. PMID: 8275191
Lung cancer: A prospective study of smoking, occupation, and nutrient intakeKato I, Nomura AM, Stemmermann GN, Chyou PH
A cohort study of lung cancer was conducted among 7,961 Japanese-American men who were interviewed and examined during 1965-1968. Information was collected about their smoking history, occupation, and nutrient intake. After 22 y, 227 incident cases of lung cancer were identified. Cigarette smoking significantly increased lung cancer risk. The relative risk (RR) was 3.1 for past smokers and 11.4 for current smokers, compared with never smokers. We separated lung cancer cases according to histological type, and it was found that current smokers had a RRs of 16.0 for squamous/small-cell carcinoma and 6.8 for adenocarcinoma of the lung. Unskilled manual workers had a significantly higher risk (RR = 1.5; 95% confidence interval, 1.1-2.2) for lung cancer than workers who were engaged in nonmanual occupations. There was no association between lung cancer and the 24-h intake of total calories, protein, fat, dietary cholesterol, carbohydrates, and alcohol, but this may have resulted from the limitations of a 24-h dietary questionnaire.
Arch Environ Health. 1993 Mar-Apr;48(2):69-72. PMID: 8476306