alpha-carotene and Colorectal-Neoplasms

The effect of beta-carotene supplementation on major serum carotenoid fractions (lutein/zeaxanthin, beta-cryptoxanthin, lycopene, alpha-carotene, and beta-carotene) was investigated in 224 people with colorectal adenomas (139 men, 85 women) recruited for the Australian Polyp Prevention Project (APPP). Each subject was randomly assigned to take either 20 mg beta-carotene/d or placebo over 24 mo. Besides the expected increase in serum concentration of beta-carotene (1073% in men, 839% in women), lycopene (176% in men) and alpha-carotene (211% in men and 166% in women) concentrations were also increased after body mass index, baseline concentration, change in respective carotenoid intake, and other confounding factors were adjusted for. The increase in serum concentrations of these carotenoids after beta-carotene supplementation suggests that beta-carotene may interact biologically with other carotenoids and such interaction would need to be taken into consideration when the protective effect of beta-carotene supplementation for cancer or other diseases is examined.

Topics: Adenoma; Adult; Aged; beta Carotene; Body Mass Index; Carotenoids; Colorectal Neoplasms; Cryptoxanthins; Dietary Fats; Double-Blind Method; Energy Intake; Female; Humans; Lipids; Lutein; Lycopene; Male; Middle Aged; Placebos; Xanthophylls; Zeaxanthins

Previous epidemiological studies on the association between circulating carotenoids and the risk of colorectal cancer drew inconclusive conclusions. This study aimed to examine serum carotenoids in relation to colorectal cancer risk in a Chinese population.. One case-control study beginning from July 2010, consecutively recruited 538 eligible colorectal cancer cases and 564 age (5-year interval) and sex frequency-matched controls. Serum levels of α-carotene, β-carotene, β-cryptoxanthin, lycopene and lutein/zeaxanthin were detected by HPLC. Unconditional logistic regression was used to estimate the odds ratio (OR) and 95% confidence internal (CI) after adjusting for various confounders. Serum levels of α-carotene, β-cryptoxanthin and lycopene were found to be inversely associated with colorectal cancer risk. The adjusted ORs of the highest quartile relative to the lowest quartile serum level were 0.49 (95% CIs 0.33-0.72) for α-carotene, 0.44 (95% CIs 0.29-0.66) for β-cryptoxanthin, and 0.36 (95% CIs 0.24-0.54) for lycopene, respectively. The association between serum β-carotene, lutein/zeaxanthin and colorectal cancer risk was not statistically significant.. The results indicated that the incidence of colorectal cancer was associated with lower serum levels of α-carotene, β-cryptoxanthin and lycopene among Chinese population residing in Guangdong.

Topics: Adult; Aged; beta Carotene; Beta-Cryptoxanthin; Body Mass Index; Carotenoids; Case-Control Studies; China; Colorectal Neoplasms; Cryptoxanthins; Female; Humans; Incidence; Logistic Models; Lycopene; Male; Middle Aged; Risk Factors; Socioeconomic Factors

The associations between specific carotenoid intake and colorectal cancer risk remain inconsistent. The aim of this study was to examine the association between specific dietary carotenoid intake with colorectal cancer risk in Chinese adults.. From July 2010 to October 2013, 845 eligible colorectal cancer cases and 845 frequency-matched controls (age and sex) completed in-person interviews. A validated food frequency questionnaire was used to estimate dietary intake. Multivariate logistical regression models were used to calculate the odds ratio (OR) and 95% confidence intervals (95% CIs) of colorectal cancer risk after adjusting for various confounders.. A strong inverse association was found between β-cryptoxanthin intake and colorectal cancer risk. Compared with the lowest quartile, the highest quartile intake showed a risk reduction of 77% (OR 0.23, 95% CI 0.17-0.33, P trend < 0.01) after adjustment for various confounding variables. The inverse associations were also observed for α-carotene (OR 0.50, 95% CI 0.37-0.68, P trend < 0.01), β-carotene (OR 0.67, 95% CI 0.49-0.91, P trend < 0.01), and lycopene (OR 0.51, 95% CI 0.37-0.70, P trend < 0.01). There was no statistically significant association between lutein/zeaxanthin intake and colorectal cancer risk. These findings were consistent across cancer site, sources of controls, and smoking status. The inverse associations between dietary α-carotene, β-cryptoxanthin, and lycopene intake and colorectal cancer risk were found in both males and females, while inverse associations between β-carotene intake and colorectal cancer risk were only observed in males.. Consumption of α-carotene, β-carotene, β-cryptoxanthin, and lycopene was inversely associated with colorectal cancer risk. No significant association was found between lutein/zeaxanthin intake and colorectal cancer risk.

Topics: Adult; Aged; Asian People; beta Carotene; Carotenoids; Case-Control Studies; China; Colorectal Neoplasms; Cryptoxanthins; Diet; Female; Humans; Life Style; Logistic Models; Lutein; Lycopene; Male; Middle Aged; Multivariate Analysis; Risk Factors; Socioeconomic Factors; Surveys and Questionnaires; Zeaxanthins

To investigate the associations between serum concentrations of carotenoids and the presence of colorectal polyps and cancers in Japanese using a cross-sectional study.. 893 subjects who underwent colorectal endoscopy between 2001 and 2002 provided serum samples and information on lifestyle factors. Serum concentrations of six carotenoids were compared among patients with polyps, cancers, and controls.. In males, high serum zeaxanthin was associated with decreased rates of polyps [odds ratio (OR) = 0.48, 95 % confidence interval (CI) 0.27-0.87] and cancer (OR = 0.35, 95 % CI 0.12-1.06), adjusting for age, body mass index, serum cholesterol, smoking status, and alcohol intake. In females, zeaxanthin (OR = 0.25, 95 % CI 0.07-0.82), lutein (OR = 0.30, 95 % CI 0.10-0.94), alpha-carotene (OR = 0.30, 95 % CI 0.10-0.90), and beta-carotene (OR = 0.27, 95 % CI 0.09-0.85) showed significant inverse associations with cancer development. These associations were consistent with findings of inverse associations between the ingestion of green-yellow vegetables (OR = 0.44, 95 % CI 0.23-0.84), carrots and pumpkins (OR = 0.46, 95 % CI 0.25-0.86), and fruits (OR = 0.53, 95 % CI 0.30-0.94) and polyp in males, and between carrots and pumpkins (OR = 0.30, 95 % CI 0.09-0.99), legumes (OR = 0.14, 95 % CI 0.04-0.44), and seaweed (OR = 0.23, 95 % CI 0.07-0.75) and cancer development in females.. These results provide further support for the protective effects of carotenoids contained in green-yellow vegetables and fruits against colorectal neoplasm in Japanese.

Topics: Aged; beta Carotene; Carotenoids; Colorectal Neoplasms; Endoscopy; Female; Fruit; Humans; Japan; Lutein; Male; Middle Aged; Polyps; Risk Factors; Vegetables; Xanthophylls; Zeaxanthins