Serum levels of n-3 PUFA and colorectal cancer risk in Chinese population.

Circulating n-3 PUFA, which integrate endogenous and exogenous n-3 PUFA, can be better used to investigate the relationship between n-3 PUFA and disease. However, studies examining the associations between circulating n-3 PUFA and colorectal cancer (CRC) risk were limited, and the results remained inconclusive. This case­control study aimed to examine the association between serum n-3 PUFA and CRC risk in Chinese population. A total of 680 CRC cases and 680 sex- and age-matched (5-year interval) controls were included. Fatty acids were assayed by GC. OR and 95 % CI were calculated using multivariable logistic regression after adjustment for potential confounders. Higher level of serum α-linolenic acid (ALA), docosapentaenoic acid (DPA), DHA, long-chain n-3 PUFA and total n-3 PUFA were associated with lower odds of CRC. The adjusted OR and 95 % CI were 0·34 (0·24, 0·49, Pfor trend < 0·001) for ALA, 0·57 (0·40, 0·80, Pfor trend < 0·001) for DPA, 0·48 (0·34, 0·68, Pfor trend < 0·001) for DHA, 0·39 (0·27, 0·56, Pfor trend < 0·001) for long-chain n-3 PUFA and 0·31 (0·22, 0·45, Pfor trend < 0·001) for total n-3 PUFA comparing the highest with the lowest quartile. However, there was no statistically significant association between EPA and odds of CRC. Analysis stratified by sex showed that ALA, DHA, long-chain n-3 PUFA and total n-3 PUFA were inversely associated with odds of CRC in both sexes. This study indicated that serum ALA, DPA, DHA, long-chain n-3 PUFA and total n-3 PUFA were inversely associated with odds of having CRC in Chinese population.

Educational level and colorectal cancer risk: the mediating roles of lifestyle and dietary factors.

OBJECTIVE: The association between the educational level and colorectal cancer risk was controversial in developed countries and evidence was limited in Chinese population. This study aimed to investigate the association between the educational level and colorectal cancer risk in Guangdong Province, China. METHODS: From July 2010 to April 2019, 2502 newly diagnosed colorectal cancer patients and 2538 sex- and age-matched controls were recruited in this case-control study. Multivariable logistic regression models were used to examine the association between the educational level and colorectal cancer risk. Path analysis was used to investigate whether behavioral risk factors potentially mediated the association between the educational level and colorectal cancer risk. RESULTS: Educational level was inversely associated with the colorectal cancer risk. People who graduated from the college or above had a lower risk of colorectal cancer than those from the primary school or below, with an adjusted odds ratio of 0.42 [95% confidence intervals (CI), 0.34-0.52]. The total, direct and indirect effects of the educational level for the colorectal cancer risk were statistically significant in the path diagram. Path analysis showed that lower red and processed meat intake and higher tea and coffee drinking among high educational participants contributed to the inverse association between the educational level and colorectal cancer risk. CONCLUSION: The findings suggested that the educational level was inversely associated with the colorectal cancer risk. The association might be mediated by red and processed meat intake, household and leisure-time activities, and tea and coffee drinking.

Association between Dietary Zinc and Selenium Intake, Oxidative Stress-Related Gene Polymorphism, and Colorectal Cancer Risk in Chinese Population - A Case-Control Study.

Zinc and selenium may protect against colorectal cancer (CRC) progression through their anti-oxidative effects. This study examined the independent and combined effect of dietary zinc and selenium intake, and polymorphisms of the oxidative stress-related genes (superoxide dismutase 1, superoxide dismutase 2, glutathione peroxidase, and catalase) on CRC risk in a Chinese case-control study. A total of 493 cases and 498 sex and age-matched controls were randomly selected from an ongoing case-control study. Dietary information was assessed through face-to-face interviews using a validated food frequency questionnaire. Multiplex PCR-ligase detection reaction was used for genotyping the target SNPs. Multivariable logistic regression was used to estimate the odds ratios (ORs) and 95% confidence interval (CI). Intake of selenium was found to be inversely associated with CRC risk, while zinc was not associated with CRC risk. The ORs (95% CI) for the highest vs. the lowest quartile were 0.42 (95% CI 0.28, 0.64, Ptrend < 0.001) for selenium and 0.96 (95% CI 0.63, 1.47, Ptrend = 0.505) for zinc. Combined effect was observed between zinc and SOD1 rs4998557 on CRC risk (Pinteraction < 0.05). This study identified a novel diet-gene interaction in the oxidative stress pathway on CRC risk in Chinese population.

Association between phytosterol intake and colorectal cancer risk: a case-control study.

A study in rodent models showed that phytosterols protected against colon carcinogenesis, probably by inhibiting dysregulated cell cycle progression and inducing cellular apoptosis. However, epidemiological studies on the relationship between phytosterols and colorectal cancer risk are quite limited. The aim of this study was to investigate dietary phytosterol intake in relation to colorectal cancer risk in the Chinese population. A case-control study was conducted from July 2010 to June 2016, recruiting 1802 eligible colorectal cancer cases plus 1813 age (5-year interval) and sex frequency-matched controls. Dietary information was collected by using a validated FFQ. The OR and 95 % CI of colorectal cancer risk were assessed by multivariable logistic regression models. A higher total intake of phytosterols was found to be associated with a 50 % reduction in colorectal cancer risk. After adjusting for various confounders, the OR of the highest quartile intake compared with the lowest quartile intake was 0·50 (95 % CI 0·41, 0·61, P trend<0·01) for total phytosterols. An inverse association was also found between the consumption of ß-sitosterol, campesterol, campestanol and colorectal cancer risk. However, stigmasterol intake was related to an increased risk of colorectal cancer. No statistically significant association was found between ß-sitostanol and colorectal cancer risk. Stratified analysis by sex showed that the positive association of stigmasterol intake with colorectal cancer risk was found only in women. These data indicated that the consumption of total phytosterols, ß-sitosterol, campesterol and campestanol is inversely associated with colorectal cancer risk in a Chinese population.

Flavonoid intake from vegetables and fruits is inversely associated with colorectal cancer risk: a case-control study in China.

Flavonoids may play an important role in the protective effects of vegetables, fruits and tea against colorectal cancer. However, associations between flavonoids and colorectal cancer risk are inconsistent, and a few studies have evaluated the effect of flavonoids from different dietary sources separately. This study aimed to evaluate associations of flavonoids intake from different dietary sources with colorectal cancer risk in a Chinese population. From July 2010 to December 2015, 1632 eligible colorectal cancer cases and 1632 frequency-matched controls (age and sex) completed in-person interviews. A validated FFQ was used to estimate dietary flavonoids intake. Multivariate logistical regression models were used to calculate the OR and 95 % CI of colorectal cancer risk after adjusting for various confounders. No significant association was found between total flavonoids and colorectal cancer risk, with an adjusted OR of 1·06 (95 % CI 0·85, 1·32) comparing the highest with the lowest quartile. Anthocyanidins, flavanones and flavones intakes from total diet were found to be inversely associated with colorectal cancer risk. Compared with the lowest quartile, the adjusted OR for the highest quartile were 0·80 (95 % CI 0·64, 1·00) for anthocyanidins, 0·28 (95 % CI 0·22, 0·36) for flavanones and 0·54 (95 % CI 0·43, 0·67) for flavones. All subclasses of flavonoids from vegetables and fruits were inversely associated with colorectal cancer. However, no significant association was found between tea flavonoids and colorectal cancer risk. These data indicate that specific flavonoids, specifically flavonoids from vegetables and fruits, may be linked with the reduced risk of colorectal cancer.