Prospective study of three major dietary patterns and risk of gastric cancer in Japan

Dietary pattern analysis is an alternative and complementary approach to identify the relationship between diet and the risk of chronic disease. This study was aimed at investigating the associations between dietary patterns and the risk of gastric cancer in Japan. Using baseline data from a prospective study of 20,300 men and 21,812 women, we conducted factor analysis and identified 3 major dietary patterns, healthy, traditional and Western, and calculated the factor scores of each pattern for individuals. During 10 years of follow-up, 400 cases of gastric cancer were identified. We found an inverse association between the healthy pattern and gastric cancer risk in women [rate ratio for highest quartile (RR) = 0.56; 95% CI = 0.32-0.96; p for trend = 0.03], but not in men. In contrast, the traditional pattern was significantly associated with the increased risk of gastric cancer in both genders (for men, RR = 2.88, 95% CI = 1.76-4.72; for women, RR = 2.40, 95% CI = 1.32-4.35). The Western pattern was not associated with risk. These associations persisted in histologic subtypes. Our findings support the idea that the healthy pattern decreased the risk of gastric cancer among females, while the traditional pattern increased the risk in both genders.     

Statin use and colorectal cancer risk according to molecular subtypes in two large prospective cohort studies

Use of statins is hypothesized to reduce colorectal cancer risk but the evidence remains inconsistent. This may be partly explained by differential associations according to tumor location or molecular subtypes of colorectal cancer. We examined the association between statin use and colorectal cancer risk according to tumor location, KRAS mutation status, microsatellite instability (MSI) status, PTGS2 (COX-2) expression, or CpG island methylator phenotype (CIMP) status in two large prospective cohort studies, the Nurses' Health Study and Health Professionals Follow-up Study. We applied Cox regression to a competing risks analysis. We identified 1,818 colorectal cancers during 1990 to 2006. Compared with nonusers, current statin use was not associated with colorectal cancer [relative risk (RR) = 0.99, 95% CI = 0.86-1.14] or colon cancer (RR = 1.10, 95% CI = 0.94-1.29) but was inversely associated with rectal cancer (RR = 0.59, 95% CI = 0.41-0.84, P(heterogeneity) < 0.001). When we examined the association within strata of KRAS mutation status, we found no association with KRAS-mutated cancers (RR = 1.20, 95% CI = 0.87-1.67) but did observe a possible inverse association among KRAS wild-type cancers (RR = 0.80, 95% CI = 0.60-1.06, P(heterogeneity) = 0.06). The association did not substantially differ by PTGS2 expression, MSI status, or CIMP status. Current statin use was not associated with risk of overall colorectal cancer. The possibility that statin use may be associated with lower risk of rectal cancer or KRAS wild-type colorectal cancer requires further confirmation.     

A comparative case-control study of colorectal cancer and adenoma

We conducted a comparative case-control study of colorectal cancer and adenoma involving 221 cases with colorectal cancer, 525 cases with colorectal adenoma and 578 neighborhood controls. Daily vegetables intake was associated with lower risks of distal colon adenoma (relative risks (RR) = 0.59, 95% confidence interval (CI): 0.39-0.89) and rectal cancer (RR = 0.46, 95% CI: 0.25-0.84). Daily beans intake was associated with lower risk of colon adenoma (RR = 0.58, 95% CI: 0.37-0.91 for the proximal colon and RR = 0.63, 95% CI: 0.45-0.88 for the distal colon) and daily intake of seaweeds was associated with lower risk of rectal cancer (RR = 0.42, 95% CI: 0.22-0.82). Daily intake of fish and shellfish also showed an inverse association with the risk of colon adenoma (RR = 0.67, 95% CI: 0.45-0.99 for the proximal colon and RR = 0.70, 0.52-0.94 for the distal colon). Generally, intakes of animal or vegetable fat-rich foods, especially meats, were associated with decreases in risks of both adenoma and cancer, though the association of cancer was not statistically significant. Other than dietary factors, daily alcohol drinking was associated with an increased risk of adenoma in the proximal colon (RR = 1.95, 95% CI: 1.15-3.29) and ex-drinkers showed higher risks for colon adenoma and colorectal cancer. Sports or occupational activities and coffee drinking were inversely associated and family history of colorectal cancer was positively associated with the risk of both colorectal adenoma and cancer.     

Dietary supplement use and colorectal cancer risk: A systematic review and meta‐analyses of prospective cohort studies

Use of dietary supplements is rising in countries where colorectal cancer is prevalent. We conducted a systematic literature review and meta‐analyses of prospective cohort studies on dietary supplement use and colorectal cancer risk. We identified relevant studies in Medline, Embase and Cochrane up to January 2013. Original and peer‐reviewed papers on dietary supplement use and colorectal cancer, colon cancer, or rectal cancer incidence were included. “Use‐no use”(U‐NU), “highest‐lowest”(H‐L) and “dose‐response”(DR) meta‐analyses were performed. Random‐effects models were used to estimate summary estimates. In total, 24 papers were included in the meta‐analyses. We observed inverse associations for colorectal cancer risk and multivitamin (U‐NU: RR = 0.92; 95% CI: 0.87,0.97) and calcium supplements (U‐NU: RR = 0.86; 95% CI: 0.79,0.95; H‐L: RR = 0.80; 95% CI: 0.70,0.92; DR: for an increase of 100 mg/day, RR = 0.96; 95% CI: 0.94,0.99). Inconsistent associations were found for colon cancer risk and supplemental vitamin A and vitamin C, and for colorectal cancer risk and supplemental vitamin D, vitamin E, garlic and folic acid. Meta‐analyses of observational studies suggest a beneficial role for multivitamins and calcium supplements on colorectal cancer risk, while the association with other supplements and colorectal cancer risk is inconsistent. Residual confounding of lifestyle factors might be present. Before recommendations can be made, an extensive assessment of dietary supplement use and a better understanding of underlying mechanisms is needed.     

A Comparative Case-Control Study of Colorectal Cancer and Adenoma

We conducted a comparative case-control study of colorectal cancer and adenoma involving 221 cases with colorectal cancer, 525 cases with colorectal adenoma and 578 neighborhood controls. Daily vegetables intake was associated with lower risks of distal colon adenoma (relative risk (RR)=0.59, 95% confidence interval (CI): 0.39–0.89) and rectal cancer (RR=0.46, 95% CI: 0.25–0.84). Daily beans intake was associated with lower risk of colon adenoma (RR=0.58, 95% CI: 0.37–0.91 for the proximal colon and RR=0.63, 95% CI: 0.45–0.88 for the distal colon) and daily intake of seaweeds was associated with lower risk of rectal cancer (RR=0.42, 95% CI: 0.22–0.82). Daily intake of fish and shellfish also showed an inverse association with the risk of colon adenoma (RR=0.67, 95% CI: 0.45–0.99 for the proximal colon and RR=0.70, 95% CI: 0.52–0.94 for the distal colon). Generally, intakes of animal or vegetable fat-rich foods, especially meats, were associated with decreases in risks of both adenoma and cancer, though the association of cancer was not statistically significant. Other than dietary factors, daily alcohol drinking was associated with an increased risk of adenoma in the proximal colon (RR=1.95, 95% CI: 1.15–3.29) and ex-drinkers showed higher risks for colon adenoma and colorectal cancer. Sports or occupational activities and coffee drinking were inversely associated and family history of colorectal cancer was positively associated with the risks of both colorectal adenoma and cancer.     

Dietary patterns and risk of prostate cancer in U.S. men.

We prospectively investigated the associations between dietary patterns and risk of prostate cancer in the Health Professionals Follow-up Study. Between 1986 and 2000, 3,002 incident prostate cancer cases were identified in our cohort. Using factor analysis, two major dietary patterns were identified, a prudent and a western dietary pattern. Dietary patterns were not appreciably associated with risk of total prostate cancer. For the highest versus the lowest quintiles, the multivariable relative risk (RR) for the prudent pattern was 0.94 [95% confidence interval (CI), 0.83-1.06], and for the western pattern, the multivariable RR was 1.03 (95% CI, 0.92-1.17). Neither were these associated with risk of advanced prostate cancer [highest versus lowest quintile, prudent pattern (RR, 1.01; 95% CI, 0.68-1.49); western pattern (RR, 1.13; 95% CI, 0.77-1.67)]. Higher western pattern scores were suggestively associated with a greater risk of advanced prostate cancer among older men [highest versus lowest quintile (RR, 1.35; 95% CI, 0.97-1.90)], but not after adding processed meat to the model [highest versus lowest quintile (RR, 1.11; 95% CI, 0.75-1.65)]. We did not find any evidence for a protective association between prudent pattern and risk of prostate cancer. The lack of association between a western dietary pattern as identified by factor analysis in our cohort and prostate cancer risk suggests that dietary risk factors for prostate cancer are likely to differ from those for other conditions, such as cardiovascular disease and type 2 diabetes, that have been associated with a western dietary pattern in this cohort.     

Dietary patterns and colorectal cancer: systematic review and meta-analysis

Studies on the association between single foods or nutrients and colorectal cancer have provided inconsistent results. Previous reviews did not conduct a quantitative synthesis of the relation with dietary patterns. We conducted a systematic review and meta-analysis of studies addressing the association between dietary patterns and colorectal cancer. Studies quantifying the association between dietary patterns (defined a posteriori) and colorectal cancer were identified in PubMed (until 01.08.2010) and through backward and forward citation tracking (ISI Web of Science and Scopus). Summary relative risk (RR) estimates and 95% confidence intervals (95% CI) were computed for highest versus lowest levels of exposure, for colon cancer (CC) and rectal cancer (RC), and for proximal and distal CC, by random effects meta-analysis. Heterogeneity was quantified using the I(2) statistic. Eight cohort and eight case-control studies defining patterns through principal components and factor analyses were included in the systematic review. Meta-analyses were conducted for three patterns: (i) 'drinker,' characterized by high alcohol consumption (CC: RR(combined)=0.96, 95% CI: 0.82-1.12, I(2)=0.6%; RC: RR(combined)=0.83, 95% CI: 0.47-1.45, I(2)=65.1%); (ii) 'healthy,' characterized by high fruit/vegetables consumption (CC: RR(combined)=0.80, 95% CI: 0.70-0.90, I(2)=55.1%; RC: RR(combined)=1.02, 95% CI: 0.89-1.17, I(2)=10.8%); (iii) 'western,' characterized by high red/processed meat consumption (CC: RR(combined)=1.29, 95% CI: 1.13-1.48, I(2)=31.7%; RC: RR(combined)=1.13, 95% CI: 0.92-1.39, I(2)=40.6%). Summary estimates for proximal and distal CC were similar. The risk of CC was increased with patterns characterized by high intake of red and processed meat and decreased with those labelled as 'healthy.' No significant associations were observed for RC.     

Mismatch repair polymorphisms and the risk of colorectal cancer

Rare germline variants in mismatch repair genes have been linked to hereditary nonpolyposis colorectal cancer; however, it is unknown whether common polymorphisms in these genes alter the risk of colorectal cancer. To examine the association between common variants in mismatch repair genes and colorectal cancer, we conducted a case-cohort study within the CLUE II cohort. Four single nucleotide polymorphisms in 3 mismatch repair genes (MSH3 R940Q, MSH3 T1036A, MSH6 G39E and MLH1 I219V) were genotyped in 237 colorectal cancer cases and a subcohort of 2,189 participants. Incidence rate ratios (RRs) and 95% confidence intervals (95% CIs) for each polymorphism were estimated. The MSH3 1036A variant was found to be associated with an increased risk of colorectal cancer (RR=1.28, 95% CI: 0.94-1.74 and RR=1.65, 95% CI: 1.01-2.70 for the AT and TT genotypes, respectively, with p(trend)=0.02), particularly proximal colon cancer. Although the MSH3 940Q variant was only weakly associated with colorectal cancer overall (p(trend)=0.07), it was associated with a significant increased risk of proximal colon cancer (RR=1.69, 95% CI: 1.10-2.61 and RR=2.68, 95% CI: 0.96-7.47 for the RQ and QQ genotypes, respectively with p(trend)=0.005). Processed meat intake appeared to modify the association between the MSH3 polymorphisms and colorectal cancer (p(interaction) < 0.10 for both). No association was observed with the MSH6 and MLH1 polymorphisms overall. This study suggests that common polymorphisms in the mismatch repair gene, MSH3, may increase the risk of colorectal cancer, especially proximal colon cancer.     

Dietary patterns associated with male lung cancer risk in the Netherlands Cohort Study.

The objective of this article was to study the association between dietary patterns and lung cancer incidence in the Netherlands Cohort Study on Diet and Cancer. The baseline measurement of this prospective case cohort study that was completed by 58,279 men in 1986 included a self-administered questionnaire on dietary intake, smoking habits, and other covariates. Follow-up was established by computerized record linkage to cancer registries and a pathology register. After 9.3 years of follow-up, 1,426 confirmed cases of incident male lung cancer were detected. Five dietary patterns were identified by exploratory factor analysis in a randomly sampled subcohort (n = 2,190). The dietary pattern labeled "salad vegetables" was associated with decreased risk of lung cancer [rate ratios (RR)(Q5), 0.75; 95% confidence interval (CI), 0.55-1.01], after multivariate adjustment. This inverse association was most evident among current and former smokers. A dietary pattern labeled "sweet foods" was also inversely associated with lung cancer risk (RR(Q5), 0.62; 95% CI, 0.43-0.89). However, the higher intake of monosaccharides and disaccharides, fruits, and lower consumption of alcohol associated with this pattern could not account for its full protective effect. The "pork, processed meat, and potatoes" pattern was nonsignificantly associated with increased risk (RR(Q5), 1.44; 95% CI, 0.99-2.09), and this positive association was most evident among current smokers. The other dietary patterns characterized by brown/white bread substitution and by consumption of cooked vegetables were not associated with lung cancer risk. These results show how studying both single factors and dietary patterns gives more insight into the complex, and often seemingly inconsistent, associations between diet and cancer.     

Coffee consumption and risk of colorectal cancer: A systematic review and meta‐analysis of prospective cohort studies

An inverse association between coffee consumption and the risk of colorectal cancer has been found in several case‐control studies, but such an association was not consistent in prospective cohort studies. We conducted a systematic meta‐analysis of prospective cohort studies on coffee consumption and colorectal cancer published up to June 2008. We combined relative risks (RR) for colorectal cancer comparing high vs. low categories of coffee consumption using random‐effects models. We identified 12 eligible cohort studies, which included 646,848 participants and 5,403 cases for colorectal cancer. The summarized result of the meta‐analysis comparing high‐ vs. low‐consumption categories showed no significant effect of coffee consumption on colorectal cancer risk (RR = 0.91; 95% confidence intervals [CI]: 0.81–1.02). The RR was 0.93 (95% CI: 0.71–1.22) when considering 4 studies conducted in the United States of America, 0.91 (95% CI: 0.76–1.10) for 5 studies from Europe, and 0.83 (95% CI: 0.62–1.10) for 3 Japanese studies. No significant differences by sex and cancer‐site were found, but there was a slight suggestion of an inverse association between coffee consumption and colon cancer in women (RR = 0.79; 95% CI: 0.60–1.04), especially Japanese women (RR = 0.62; 95% CI: 0.37–1.05). The suggestive inverse associations were slightly stronger in studies that controlled for smoking and alcohol, and in studies with shorter follow‐up times. Information on coffee type, its serving size, or brewing method may provide a better understanding of this reassuring result and the real role of coffee on colorectal cancer risk. © 2008 Wiley‐Liss, Inc.     

Dietary Patterns and Stomach Cancer among Middle-aged Male Workers in Tokyo

Many epidemiological studies have examined the associations of nutrients and foods with risk of stomach cancer. ‍Few studies have addressed the dietary patterns that reflect various components of food consumption and their ‍interactions. We identified major four dietary patterns; “vegetable and fruit”, “Western breakfast”, “meat”, and ‍“rice/snack” with principal component analysis using food consumption questionnaire in a prospective study of ‍5,765 middle-aged male workers in Tokyo. After 10 years of follow-up between September 1988 and August 1998, 84 ‍incident cases of stomach cancer were documented. Using proportional hazards regression to estimate risk ratios, ‍we found no clear association between each of dietary pattern and stomach cancer risk. After adjustment for age ‍and other potential confounding factors and after exclusion of the cases diagnosed in first follow-up year, the risk ‍ratio(RR) associated with high tertile compared to low tertile was 0.78(95%CI 0.42-1.44) for “vegetable and fruit” ‍pattern and 0.71(95%CI 0.40-1.24) for “Western breakfast” pattern. The V-shaped associations between dietary ‍patterns and stomach cancer risk were appeared in the “meat”(RR=1.00, 0.55, and 1.10) and the “rice/snack”(RR=1.00, ‍0.52, and 1.19) patterns, while the linear trend of these associations was statistically on borderline. The roll of overall ‍dietary patterns in predicting stomach cancer risk requires further investigation.     

No Inhibition of Urinary Bladder Carcinogenesis in Rats with Intravesical Instillation of -Galactosylceramide

Many epidemiological studies have examined the associations of nutrients and foods with risk of stomach cancer. ‍Few studies have addressed the dietary patterns that reflect various components of food consumption and their ‍interactions. We identified major four dietary patterns; “vegetable and fruit”, “Western breakfast”, “meat”, and ‍“rice/snack” with principal component analysis using food consumption questionnaire in a prospective study of ‍5,765 middle-aged male workers in Tokyo. After 10 years of follow-up between September 1988 and August 1998, 84 ‍incident cases of stomach cancer were documented. Using proportional hazards regression to estimate risk ratios, ‍we found no clear association between each of dietary pattern and stomach cancer risk. After adjustment for age ‍and other potential confounding factors and after exclusion of the cases diagnosed in first follow-up year, the risk ‍ratio(RR) associated with high tertile compared to low tertile was 0.78(95%CI 0.42-1.44) for “vegetable and fruit” ‍pattern and 0.71(95%CI 0.40-1.24) for “Western breakfast” pattern. The V-shaped associations between dietary ‍patterns and stomach cancer risk were appeared in the “meat”(RR=1.00, 0.55, and 1.10) and the “rice/snack”(RR=1.00, ‍0.52, and 1.19) patterns, while the linear trend of these associations was statistically on borderline. The roll of overall ‍dietary patterns in predicting stomach cancer risk requires further investigation. ‍     

Meat subtypes and their association with colorectal cancer: Systematic review and meta‐analysis

Associations between specific red meat subtypes and risk of colorectal cancer (CRC) have been investigated in a number of epidemiological studies. However, no publication to date has summarised the overall epidemiological evidence. We conducted a systematic review and meta‐analysis of prospective studies (cohort, nested case‐control or case‐cohort studies), which reported relative risk (RR) estimates and 95% confidence intervals (CI) for the association between intake of meat subtypes with colorectal, colon or rectal cancer or colorectal adenoma risk. PubMed and ISI Web of Science were searched up until August 1, 2014. Nineteen studies examined meat subtypes (5 beef, 5 pork, 2 lamb, 1 veal and 19 poultry) and associations with colorectal, colon or rectal cancer risk and 4 studies examined associations with adenoma risk (1 beef and 4 poultry). Comparing highest versus lowest intake, beef consumption was associated with an increased risk of CRC (RR = 1.11, 95% CI = 1.01 to 1.22) and colon cancer (RR = 1.24, 95% CI = 1.07 to 1.44), but no association was found with rectal cancer (RR = 0.95, 95% CI = 0.78 to 1.16). Higher consumption of lamb was also associated with increased risk of CRC (RR = 1.24, 95% CI = 1.08 to 1.44). No association was observed for pork (RR = 1.07, 95% CI = 0.90 to 1.27), but some between study heterogeneity was observed. No association was observed for poultry consumption and risk of colorectal adenomas or cancer. This meta‐analysis suggests that red meat subtypes differ in their association with CRC and its sub sites. Further analysis of data from prospective cohort studies is warranted, especially regarding the role of pork.     

Dietary patterns and risk of colon cancer and adenoma in a cohort of men (United States)

BackgroundExamining the effects of dietary patterns on cancer risk may provide insights beyond the assessment of individual foods or nutrients. Design: In the health professionals follow-up cohort, associations between the prudent and the western dietary pattern and risk of colon cancer and adenomas were examined in 561 colon cancer cases and 1207 distal colon adenoma cases. Results: Higher prudent pattern scores were only weakly and non-significantly associated with decreased risk of colon cancer or distal colon adenoma (highest versus lowest quintile: colon cancer: multivariate adjusted relative risk (RR)=0.84 (95 confidence interval (CI)=0.64–1.10); p_trend=0.37; distal adenoma: multivariate odds ratio (OR)=0.88 (95 CI=0.73–1.08); p_trend=0.12). Our findings suggest a moderately increased risk of colon cancer and distal adenoma with higher western pattern scores (colon cancer: RR=1.27 (95 CI=0.96–1.69), p_trend=0.05; distal adenoma: OR=1.28 (95 CI=1.05–1.56), p_trend=0.01). Adding body mass index, which is positively related to western pattern and thus may be considered an intermediate endpoint between western pattern and colon cancer, attenuated associations somewhat but not substantially. Conclusion: Our data do not provide evidence for an appreciable inverse association between higher prudent pattern scores and risk of colon cancer or distal colon adenomas, but do support a moderate positive association between higher western pattern scores and risk of colon cancer or distal colon adenomas.     

Western diet, family history of colorectal cancer, NAT2, GSTM-1 and risk of colon cancer

Objective: In this study we examine the combined effects of Western diet, age at diagnosis, and genetic susceptibility.Methods: We use data collected as part of an incident case–control study of colon cancer. Family history of colorectal cancer, N-acetyltransferase (NAT2), and gluathione-S-transferase (GSTM-1) are studied with Western diet and age at diagnosis.Results: A significant interaction between age at time of diagnosis, Western dietary pattern, and family history of colorectal cancer (p for interaction = 0.03) was detected. Those with a family history of colorectal cancer who ate a predominantly Western diet were at increased risk of colon cancer (OR 14.0, 95% CI 3.9–50.1 for 55 years; OR 7.7, 95% CI 2.0–29.1 for 56–66 years; OR 1.6, 95% CI 0.8–3.2 for 67 years) compared to those without a family history of colorectal cancer and low levels of a Western diet. Associations with the Western diet were stronger than individual components of the dietary pattern. Neither NAT2 nor GSTM-1 showed significant interaction with Western diet.Conclusion: The extent to which diet comprising a Western dietary pattern influences risk of colon cancer is dependent on age. This dietary pattern also appears to modulate the colon cancer risk associated with a family history of colon cancer.     

Dietary marine n-3 fatty acids in relation to risk of distal colorectal adenoma in women.

Epidemiologic studies of dietary marine n-3 fatty acids and risk of colorectal cancer have been inconsistent, and their relation to risk of colorectal adenoma has not been evaluated in detail. We examined dietary marine n-3 fatty acids and the ratio of marine n-3 to total n-6 fatty acids (n-3/n-6 ratio) in relation to risk of adenoma of the distal colon or rectum among 34,451 U.S. women who were initially free of colorectal cancer or polyps, who completed a semiquantitative food frequency questionnaire in 1980, and who underwent endoscopy from 1980 to 1998. We documented 1,719 distal colorectal adenoma cases (705 large adenomas, 897 small adenomas, 1,280 distal colon adenomas, and 505 rectal adenomas) during 18 years of follow-up. Neither dietary marine n-3 fatty acids nor n-3/n-6 ratio were associated with risk of total distal colorectal adenoma after adjustment for age and established risk factors [multivariable relative risk (RR) for extreme quintiles of dietary marine n-3 fatty acids = 1.04; 95% confidence interval (95% CI), 0.84-1.27, P(trend) = 0.66; RR for extreme quintiles of n-3/n-6 ratio = 1.02; 95% CI, 0.83-1.25; P(trend) = 0.86]. Similarly, no significant associations were observed separately for distal colon or rectal adenoma. However, higher intake of dietary marine n-3 fatty acids was nonsignificantly but suggestively inversely associated with large adenoma (RR, 0.74; 95% CI, 0.54-1.01; P(trend) = 0.16) but directly associated with small adenoma (RR, 1.36; 95% CI, 1.02-1.81; P(trend) = 0.09). Our findings do not support the hypothesis that a higher intake of marine n-3 fatty acids or a higher n-3/n-6 ratio reduces the risk of distal colorectal adenoma but are suggestive that higher intake may reduce the progression of small adenomas to large adenomas.     

Green tea and black tea consumption in relation to colorectal cancer risk: the Singapore Chinese Health Study

The relationships between green tea and black tea consumption and colorectal cancer risk were examined within the Singapore Chinese Health Study, a prospective cohort study of diet and cancer involving >60,000 men and women. Intake of green tea and black tea was assessed through in-person interviews. Incident cancer cases and deaths among cohort members were identified through record linkage of the cohort database with respective databases from the nationwide Singapore Cancer Registry and the Singapore Registry of Births and Deaths. The proportional hazard regression method was used to examine the associations between intake of green and black tea separately and colorectal cancer risk with adjustment for potential confounders. After an average of 8.9 years of follow-up, 845 colorectal cancer cases were identified. Subjects who drank green tea exhibited a statistically non-significant increase in risk [relative risk (RR) = 1.12, 95% confidence interval (CI) = 0.97-1.29] relative to non-drinkers of green tea. This risk increase was mainly confined to men (RR = 1.31, 95% CI = 1.08-1.58); the comparable RR in women was 0.89 (95% CI = 0.71-1.12). In men, the green tea-colorectal cancer association was noted mainly in those with advanced disease (Duke C or D) (RR = 1.53, 95% CI = 1.19-1.97), and the association was dose dependent (P for trend = 0.0002). This latter association was especially strong within the colon subsite (RR = 1.75, 95% CI = 1.24-2.46; P for trend < 0.0001). Irrespective of gender, intake of black tea was not associated with risk of colorectal cancer (RR = 0.92, 95% CI = 0.79-1.07) in this Asian population.     

Glycemic index, glycemic load, and carbohydrate intake in relation to risk of distal colorectal adenoma in women.

Case-control studies and a cohort study have shown inconsistent associations between a high glycemic index or a high glycemic load and risk of colorectal cancer. These dietary variables have not been examined in relation to risk of colorectal adenoma. We thus examined the associations between dietary glycemic index, glycemic load, and carbohydrate intake with risk of adenoma of the distal colon or rectum among 34,428 US women who were initially free of cancer or polyps, who completed a semi-quantitative food-frequency questionnaire in 1980, and who underwent endoscopy from 1980 through 1998. 1,715 adenoma cases (704 large adenomas, 894 small adenomas, 1,277 distal colon adenomas, and 504 rectal adenomas) were documented during 18 years of follow-up. Dietary glycemic index, glycemic load, and carbohydrate intake were not related to risk of total colorectal adenoma after adjustment for age and established risk factors [relative risk (RR) for extreme quintiles of glycemic index = 1.11, 95% confidence interval (CI) 0.94-1.32, P for trend = 0.66; RR for glycemic load = 0.92, 95% CI 0.76-1.11, P for trend = 0.63; RR for carbohydrate intake = 0.90, 95% CI 0.73-1.11, P for trend = 0.64]. In addition, no significant associations were found for large or small adenoma, distal colon or rectal adenoma, or across strata of body mass index. Our findings do not support the hypothesis that a high glycemic index diet, a high glycemic load diet, or high carbohydrate intake overall are associated with risk of colorectal adenoma.     

Metabolic syndrome and risks of colon and rectal cancer: the European prospective investigation into cancer and nutrition study

Metabolic syndrome (MetS) is purportedly related to risk of developing colorectal cancer; however, the association of MetS, as defined according to recent international criteria, and colorectal cancer has not been yet evaluated. In particular, it remains unclear to what extent the MetS components individually account for such an association. We addressed these issues in a nested case-control study that included 1,093 incident cases matched (1:1) to controls by using incidence density sampling. Conditional logistic regression was used to estimate relative risks (RR) and 95% CIs. MetS was defined according to the criteria of the National Cholesterol Education Program/Adult Treatment Panel III (NCEP/ATPIII), the International Diabetes Federation (IDF), and the 2009 harmonized definition. Among individual components, abdominal obesity (RR = 1.51; 95% CI: 1.16-1.96) was associated with colon cancer, whereas abnormal glucose metabolism was associated with both colon (RR = 2.05; 95% CI: 1.57-2.68) and rectal cancer (RR = 2.07; 95% CI: 1.45-2.96). MetS, as defined by each of the definitions, was similarly associated with colon cancer (e.g., RR = 1.91; 95% CI: 1.47-2.42 for MetS by NCEP/ATPIII), whereas MetS by NCEP/ATPIII, but not IDF or harmonized definition, was associated with rectal cancer (RR = 1.45; 95% CI: 1.02-2.06). Overall, these associations were stronger in women than in men. However, the association between MetS and colorectal cancer was accounted for by abdominal obesity and abnormal glucose metabolism such that MetS did not provide risk information beyond these components (likelihood ratio test P = 0.10 for MetS by NCEP/ATPIII). These data suggest that simple assessment of abnormal glucose metabolism and/or abdominal obesity to identify individuals at colorectal cancer risk may have higher clinical utility than applying more complex MetS definitions.     

Intake of dietary folate vitamers and risk of colorectal carcinoma: results from The Netherlands Cohort Study

BACKGROUND: Several studies have reported inverse associations between folate intake and colorectal carcinoma risk. Few were prospective studies and none evaluated the association between the intake of individual folate vitamers and colorectal carcinoma risk. METHODS: The aim of the current study was to investigate the relationship between dietary folate intake and the risk of colorectal carcinoma in a large prospective cohort study in The Netherlands comprising 120,852 men and women aged 55-69 years. After 7.3 years of follow-up, 760 colon and 411 rectal carcinoma cases were available for analysis. Data processing and analysis used the case-cohort approach. A new Dutch database was used to estimate intakes of total and individual folate vitamers. RESULTS: Analyses adjusted for age, energy intake, family history of colorectal carcinoma, alcohol, vitamin C, iron, and dietary fiber intake yielded an inverse association between colon carcinoma risk and total dietary folate intake (rate ratio [RR]highest vs. lowest quintile, men: 0.73; 95% confidence interval [CI], 0.46-1.17, P trend = 0.03; women: 0.68; 95% CI, 0.39-1.20, P trend = 0.18). An inverse association between rectal carcinoma and total dietary folate intake was found only among men (RR highest vs. lowest quintile, men: 0.66; 95% CI, 0.35-1.21, P trend = 0.03). Analyses showed no clear difference in colorectal carcinoma risk associated with intake of different folate vitamers. CONCLUSIONS: Dietary folate intake was related inversely to colon and male rectal carcinoma risk.