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K Tamakoshi,
K Wakai,
M Kojima,
Y Watanabe,
N Hayakawa,
H Toyoshima,
H Yatsuya,
T Kondo,
S Tokudome,
S Hashimoto, K Suzuki,
Y Ito,
A Tamakoshi
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ABSTRACT: To determine whether body size measurements are risk factors for colon cancer death among the Japanese.
A nationwide prospective study, the Japan Collaborative Cohort (JACC) Study from 1988 to 1999. The present analysis included 43 171 men and 58 775 women aged 40-79 y who respond to a questionnaire on current weight and height, weight around 20 y of age, and other lifestyle factors. Body mass index (BMI) at baseline and 20 y of age (B-BMI and 20-BMI, respectively) were calculated.
We identified 127 deaths from colon cancer during the follow-up of 424 698 person-years among men and 122 deaths during the follow-up of 591 787 person-years among women. After adjustments for the lifestyle factors known to modify the risk of colon cancer, weight at baseline showed a significant positive association in women, while no such association was seen in men. There was also a significant trend of increasing risk with the increase in B-BMI among women. Women with B-BMI >/=28 kg/m(2) had a relative risk (RR) of 3.41 (95% confidence interval (CI): 1.44-8.06) compared with those with BMI of 20-<22 kg/m(2). 20-BMI also presented the same trend of increasing risk as B-BMI. Women with 20-BMI of <22 and B-BMI of >26 kg/m(2), that is, excessive BMI gain, had a high RR of 3.41 (95% CI 1.29-9.02) compared with those with 20-BMI of <22 and B-BMI of <22 kg/m(2). There were no corresponding trends of colon cancer risk for B-BMI, 20-BMI, or BMI change among men.
These study data suggest that obesity and excessive weight gain are associated with the risk of colon cancer death in Japanese women but no such relationship was found in Japanese men.
International Journal of Obesity 05/2004; 28(4):551-8. · 4.69 Impact Factor
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M Kojima,
K Wakai,
S Tokudome,
K Tamakoshi,
H Toyoshima,
Y Watanabe,
N Hayakawa, K Suzuki,
S Hashimoto,
Y Ito,
A Tamakoshi
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ABSTRACT: The relationship between bowel movement (BM) frequency and the risk of colorectal cancer was examined in a large cohort of 25 731 men and 37 198 women living in 24 communities in Japan. At enrolment, each participant completed a self-administrated questionnaire on BM frequency and laxative use. Incidence rate ratios (IRR) with 95% confidence intervals (CI) were estimated using Cox's proportional-hazard model. During the follow-up period (average length 7.6 years), 649 cases of colorectal cancer, including 429 cases of colon cancer, were identified. Among women, subjects who reported a BM every 2-3 days had the lowest risk of developing colorectal (IRR=0.71, 95% CI=0.52-0.97) and colon cancer (IRR=0.70, 95% CI=0.49-1.00), whereas those reporting a BM every 6 days or less had an increased risk of developing colorectal (IRR=2.47, 95% CI=1.01-6.01) and colon cancer (IRR=2.52, 95% CI=0.93-6.82) compared with those reporting >or=1 BM per day. A similar, but nonsignificant, association between the frequency of BM and cancer risk was observed in men. There was no association between colorectal or colon cancer risk and laxative use. Regulating BM frequency might therefore have a role in the prevention of colorectal cancer.
British Journal of Cancer 04/2004; 90(7):1397-401. · 5.04 Impact Factor
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K Ozasa,
Y Watanabe,
Y Ito, K Suzuki,
A Tamakoshi,
N Seki,
Y Nishino,
T Kondo,
K Wakai,
M Ando,
Y Ohno
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ABSTRACT: Lung cancer has increased and is the leading cause of cancer death among Japanese males. The associations of dietary habits with the risk of lung cancer death were evaluated by sex and smoking habits in this study. In the Japan Collaborative Cohort (JACC) Study, a cohort established in 1988 - 90 and consisting of 42 940 males and 55 308 females was observed for lung cancer deaths up to the end of 1997. During the observation period, 446 males and 126 females died of lung cancer. A self-administered food frequency questionnaire was used as the baseline survey. Hazard ratios for dietary factors were calculated by Cox's proportional hazards model. Among males, a high intake of ham and sausages, cheese, green-leafy vegetables, oranges, and other fruits significantly and dose-dependently decreased the risk of lung cancer death. Among females, a high intake of miso-soup, ham and sausages, and liver significantly and almost dose-dependently increased the risk. Vegetables and fruits rich in antioxidative and carcinogenic agents reduced the risk of lung cancer deaths among male smokers more than among female nonsmokers. The results among female nonsmokers were partially consistent with the hypothesis that high fat consumption increases the risk of lung cancer, especially that of adenocarcinoma.
Japanese journal of cancer research: Gann 01/2002; 92(12):1259-69.
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N Iwai,
S Hisamichi,
N Hayakawa,
Y Inaba,
T Nagaoka,
H Sugimori,
N Seki,
K Sakata, K Suzuki,
A Tamakoshi, [......],
A Ogihara,
N Okamoto,
H Suzuki,
S Morioka,
Y Ito,
K Wakai,
T Ojima,
H Tanaka,
T Nose,
Y Ohno
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ABSTRACT: The Japan Collaborative Cohort Study for Evaluation of Cancer Risk Sponsored by Monbusho (JACC Study) included in its self-administered questionnaires some single-item questions concerning physical activity. We examined the validity of the questions among 1,730 Japanese adults and the reliability of the questions among 1,075 Japanese adults. The validity of the sports and physical exercise questions was estimated by comparing the self-administered questionnaire responses with the time spent on the activity and the energy expenditure index for the previous 12-month period, elicited by the interviewing method used in the Japan Lifestyle Monitoring Study with a minor modification. The Spearman's rank correlation coefficients ranged from 0.43 to 0.60, showing moderate correlations. On the other hand, test-retest reliability was estimated by comparing the responses from two separate surveys conducted roughly one year apart. Weighted kappa coefficients of sports and physical exercise questions, classified according to sex and age, ranged from 0.39 to 0.56, showing moderate reliability; and those of a question about walking ranged from 0.25 to 0.39, showing fair reliability. We suggest that measuring physical activity level with these single-item questions may be appropriate for establishing baseline data that reflects long-term physical activity in a large-scale cohort study targeting lifestyle-related diseases.
Journal of Epidemiology 10/2001; 11(5):211-8. · 1.86 Impact Factor
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ABSTRACT: To evaluate the impact of smoking cessation in individuals and populations, we examined the decrease in risk of lung cancer death in male ex-smokers by age at quitting in the Japan Collaborative Cohort Study for Evaluation of Cancer Risk Sponsored by Monbusho (JACC Study), which was initiated from 1988 to 1990 in Japan. For simplicity, subjects were limited to male non-smokers, and former / current smokers who started smoking at ages 18 - 22, and 33654 men aged 40 - 79 years were included. We modeled the mortality rates in non-smokers and current smokers, and compared the rates in ex-smokers with those expected from the model if they had continued smoking. During the mean follow-up of 8.0 years, 341 men died from lung cancer. The mortality rate ratio for current smokers, compared to non-smokers, was 5.16, and those for ex-smokers who had quit smoking 0 - 4, 5 - 9, 10 - 14, 15 - 19 and > or = 20 years before were 4.84, 3.19, 2.03, 1.29 and 0.99, respectively. The functions of 3.20 x 10(-7) x (age)(4.5) and 1.96 x 10(-5) x (age - 29.6)(4.5) fitted the observed mortality rates (per 100000 person-years) in non-smokers and continuing smokers, respectively. A greater decrease in lung cancer mortality was estimated among those who quit smoking at younger ages. Stopping smoking earlier in life appears preferable to keep the individual risk low. The absolute rate, however, substantially decreased after smoking cessation even in those who quit at ages 60 - 69, reflecting the high mortality rate among continuing smokers in the elderly.
Japanese journal of cancer research: Gann 08/2001; 92(8):821-8.
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K Wakai,
M Takashi,
K Okamura,
H Yuba, K Suzuki,
T Murase,
K Obata,
H Itoh,
T Kato,
M Kobayashi,
T Sakata,
T Otani,
S Ohshima,
Y Ohno
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ABSTRACT: To elucidate the role of diet in the etiology of bladder cancer, we conducted a case-control study from 1996 to 1999 in Aichi Prefecture, Central Japan. Cases were patients newly diagnosed with bladder cancer, and one hospital control was selected for each case, matching gender, age, and hospital. A well-validated food frequency questionnaire was adopted to estimate intakes of nutrients and food groups. Odds ratios (ORs) adjusted for smoking and occupational history were computed using conditional logistic models. The analyses based on 297 cases and 295 controls revealed the following. 1) The more the intake of milk and dairy products, the lower the OR; the ORs across quartiles in all subjects were 1.02, 0.73, and 0.52. Fruit intake was negatively associated with the risk, particularly in men (ORs across quartiles = 0.76, 0.77, and 0.52). Green-yellow vegetables were associated with a decreased risk in the highest quartile of consumption in men (OR = 0.57). 2) Dietary intakes of retinol and saturated fatty acids were related to a reduced risk in all subjects (ORs across quartiles = 0.75, 0.54, and 0.66 and 0.55, 0.54, and 0.60, respectively). Monounsaturated fatty acids had an inverse association with bladder cancer risk in men.
Nutrition and Cancer 02/2000; 38(1):13-22. · 2.78 Impact Factor
