beta-carotene and Intestinal-Neoplasms

In spite of diverging incidence trends, subsite, and subtype-specific gastric cancer data on the association with dietary antioxidants are sparse. We aimed to test whether the apparent protective effect of antioxidants is mainly confined to noncardia (distal) cancer of the intestinal subtype, to which most of the incidence decline in gastric cancer has been ascribed. In a Swedish study base (total population 1.3 million), we interviewed 567 cases uniformly classified to subsite (cardia vs. noncardia) and subtype (intestinal vs. diffuse), and 1165 population-based controls, frequency matched for age and sex. Serologic data on H. pylori status was available for a subset of 542 individuals. Ascorbic acid (vitamin C) was inversely associated with all subsites and subtypes of gastric cancer in a significant dose-response manner (all p<0.05), with risk reductions between 40% and 60%. beta-carotene was also strongly and negatively associated with risk, particularly with the intestinal type. The associations with alpha-tocopherol (vitamin E) were less clear. The highest parallel intake of all three antioxidants (quartiles 4), compared to those with the lowest parallel intakes (quartiles 1), was associated with a 70% lower risk of developing noncardia cancer (OR 0.3, 95% CI 0.1-0.9). Our results suggest that antioxidants might be especially beneficial among subjects at increased risk for gastric cancer such as smokers and those infected by H. pylori. We conclude that a high intake of antioxidants, as a consequence of high consumption of fruit and vegetables, may lower the risk not only for gastric cancer of the intestinal type, but also for diffuse type adenocarcinoma and cardia cancer.

Topics: Adenocarcinoma; Adult; Aged; Antioxidants; Ascorbic Acid; beta Carotene; Cardia; Case-Control Studies; Female; Fruit; Helicobacter pylori; Humans; Intestinal Neoplasms; Male; Middle Aged; Odds Ratio; Risk Factors; Smoking; Stomach Neoplasms; Sweden; Vegetables; Vitamin E

Topics: beta Carotene; Enterococcus faecium; Free Radicals; Hydrogen Peroxide; Intestinal Neoplasms; Lactobacillus; Oxygen

Male Sprague-Dawley rats were fed a diet containing either 0.005% beta-carotene, 0.02% sodium ascorbate or 1.5% cellulose for 14 weeks. Beginning on day 3, all animals were also given weekly subcutaneous injections of 1,2-dimethylhydrazine (DMH; 20 mg/kg body wt.) throughout a 12-week period. The experimental diet was continued for an additional 14 weeks. At the end of the 26th week, surviving animals were sacrificed and the incidence of intestinal carcinomas was examined. A significantly lower incidence of carcinomas was observed in the beta-carotene-fed group (55.0%), compared with that in the control group given DMH (82.1%).

Topics: 1,2-Dimethylhydrazine; Animals; Anticarcinogenic Agents; Ascorbic Acid; beta Carotene; Body Weight; Carotenoids; Cellulose; Dimethylhydrazines; Intestinal Neoplasms; Male; Rats; Rats, Sprague-Dawley

Many investigations suggested relations between fat soluble vitamin levels in blood and incidence of cancer. These studies are concerning both therapeutical efficiency of vitamins intake, seric levels and cancer risk, and the supposed correlation between blood fat soluble vitamin levels and the cancer localization. The purpose of the present study was to investigate whether the alterations of fat soluble vitamin levels (A-vitamin, beta-carotene and alpha-tocopherol) were correlated not only to carcinogenic processes but also to the localizations of their developments. In a former article, we have found that an abnormal ketone derivative of D3 vitamin (1-keto-24-methyl-25-hydroxycholecalciferol) or carcinomedin was present in the serum of all cancer patients and absent in that of healthy control subjects. Serum levels of the four above substances were determined in 1068 subjects suffering from differently localized cancers and in 880 healthy subjects. A statistical multidimensional analysis of data led a separate five groups of cancer types (p less than 0.001). Within each group alterations of vitamin spectra, compared to controls, were identical; between groups they were significantly different. These groups were: anal and intestinal cancer; pancreatic, hepatic, oesophageal and gastric cancer; laryngeal and lung cancer; uro-genital and breast cancer; brain cancer. All these groups are statistically different from the reference one (p less than 0.001). This grouping roughly corresponds to the embryologic origin of affected organs. This suggests that carcinogenesis may alter fat soluble vitamin metabolism, specifically in various forms of cancer, or these alterations of vitamin metabolism are in some way involved in the carcinogenic process.

Topics: Adult; beta Carotene; Breast Neoplasms; Calcitriol; Carotenoids; Digestive System Neoplasms; Female; Humans; Intestinal Neoplasms; Laryngeal Neoplasms; Lung Neoplasms; Male; Middle Aged; Neoplasms; Nervous System Neoplasms; Urogenital Neoplasms; Vitamin A; Vitamin E