1.
Coffee prevents proximal colorectal adenomas in Japanese men: a prospective cohort study.
Nakamura, T, Ishikawa, H, Mutoh, M, Wakabayashi, K, Kawano, A, Sakai, T, Matsuura, N
European journal of cancer prevention : the official journal of the European Cancer Prevention Organisation (ECP). 2016;(5):388-94
Abstract
This prospective cohort study aimed to show that coffee prevents the recurrence of colorectal tumors (adenomas, precursors of colorectal cancer, and early-stage colorectal cancers) as well as colorectal cancer. The present study included 307 patients who participated in a clinical study that required endoscopy to remove a colorectal tumor. The amount of coffee consumed by the patients at study inclusion and the frequency of colorectal tumors, as detected by colonoscopy over the subsequent 4 years, were assessed. Coffee consumption was determined using a diet survey that included 3-consecutive-day food records. The risk of colorectal tumor recurrence was significantly lower (odds ratio=0.21; 95% confidence interval, 0.06-0.74) in patients who consumed more than three cups of coffee per day compared with those who consumed no coffee. No correlation was observed between the examined factors, including green tea and black tea intake and the amount of caffeine consumed. In subanalysis divided by the tumor location within the colorectum, the odds ratio of colorectal tumor recurrence in the proximal colon showed a tendency toward reduction as coffee consumption increased; however, increased coffee consumption significantly increased colorectal tumor recurrence in the distal colon. We showed that high coffee consumption reduced the overall occurrence of colorectal tumors, affected by the reduction in the proximal colon.
2.
Association of visceral fat accumulation and plasma adiponectin with colorectal adenoma: evidence for participation of insulin resistance.
Otake, S, Takeda, H, Suzuki, Y, Fukui, T, Watanabe, S, Ishihama, K, Saito, T, Togashi, H, Nakamura, T, Matsuzawa, Y, et al
Clinical cancer research : an official journal of the American Association for Cancer Research. 2005;(10):3642-6
Abstract
PURPOSE Colorectal carcinogenesis is thought to be related to abdominal obesity and insulin resistance. To investigate whether visceral fat accumulation contributes to colorectal carcinogenesis, we examined its accumulation and the levels of the adipose tissue-derived hormone adiponectin in Japanese patients with colorectal adenoma. EXPERIMENTAL DESIGN Fifty-one consecutive Japanese patients ages ≥40 years and with colorectal adenoma were subjected to measurement of visceral fat area by computed tomography scanning and plasma adiponectin concentration. The patients also underwent the 75-g oral glucose tolerance test. Insulin resistance was calculated by the homeostasis metabolic assessment (HOMA-IR) method. The controls were 52 Japanese subjects ages ≥40 years and without colorectal polyp. Cigarette smokers and subjects who consumed alcohol (≥30 g ethanol/d) were excluded. RESULTS The patients with colorectal adenoma showed significantly more visceral fat area and significantly less plasma adiponectin concentration in comparison with the controls [odds ratio (OR), 2.19; 95% confidence interval (95% CI), 1.47-3.28; P < 0.001 and OR, 0.24; 95% CI, 0.14-0.41; P < 0.001, respectively] by logistic regression analysis. HOMA-IR index was also associated with colorectal adenoma (OR 2.60; 95% CI, 1.20-5.64; P = 0.040). Visceral fat area and adiponectin were associated with adenoma number (1, 2, ≥ 3), the size of the largest adenoma (<10 and ≥10 mm), and adenoma histology (tubular and tubulovillous/villous). CONCLUSIONS These results suggest an association of visceral fat accumulation and decreased plasma adiponectin concentration with colorectal adenoma in Japanese patients. This study may offer a new insight to understanding the relationship of colorectal carcinogenesis with abdominal obesity and insulin resistance.