Effects of alpha-tocopherol and beta-carotene supplements on cancer incidence in the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study

Abstract

The Alpha-Tocopherol Beta-Carotene (ATBC) Cancer Prevention Study was a placebo-controlled, randomized intervention trial testing the hypothesis that beta-carotene and alpha-tocopherol (vitamin E) supplements prevent lung and other cancers. The study is predicated on a substantial body of evidence supporting a role in cancer prevention for these micronutrients. Based on the 2 x 2 factorial study design, 29,133 eligible male cigarette smokers aged 50-69 y were randomly assigned to receive beta-carotene (20 mg), alpha-tocopherol (50 mg), beta-carotene and alpha-tocopherol, or placebo daily for 5-8 y. Capsule compliance was high (median = 99%). beta-Carotene treatment did not result in a decrease in cancer at any of the major sites but rather in an increase at several sites, most notably lung, prostate, and stomach (number of cases 474 compared with 402, 138 compared with 112, and 70 compared with 56, respectively). The vitamin E group had fewer incident cancers of the prostate and colorectum compared with the group not receiving vitamin E (number of cases 99 compared with 151 and 68 compared with 81, respectively), but more cancers of the stomach (70 compared with 56). In contrast to these intervention-based findings for beta-carotene and vitamin E supplements, we observed lower lung cancer rates in men with higher amounts of both serum and dietary beta-carotene and vitamin E at baseline.

Status of lipidsoluble antioxidants and TRAP in patients with Crohn’s disease and healthy controls

“…It may be worthwhile to undertake clinical studies with supplementation of antioxidative vitamins in order to suppress the in¯ammatory process induced by reactive oxygen and nitrogen species, as requested again recently (Jeejeebhoy, 1998). However, special care has to be taken in designing such trials, since the possible hazard of supplementing only single substances in pharmacological doses is demonstrated by the adverse outcome of recent trials with -carotene, which resulted in an increase of lung cancer in risk populations (for example Albanes et al, 1995).…”

Home‐based preparation approaches altered the availability of health beneficial components from carrot and blueberry

“…Carrot is rich in edible fiber, carotenoids, and other health beneficial compounds (Azam, Khan, Mahmood, & Hameed, 2013; Knockaert et al., 2013). Its carotenoids including β‐carotene are important for vision health, and could not be synthesized by human body and have to be obtained through diet (Albanes et al., 1995; Bendich & Shapiro, 1986; Knockaert et al., 2013). …”

Chemoprevention by the Oxygenated Carotenoid β‐Cryptoxanthin of N‐Methylnitrosourea‐induced Colon Carcinogenesis in F344 Rats

“…1,2) There is increasing evidence from epidemiological [3][4][5][6][7] and animal [7][8][9][10][11][12][13] studies that a high consumption of foods containing carotenoids such as β-carotene and lycopene, which possess potent antioxidant properties and anticarcinogenic activity, reduces the risk of colon cancer, although there were negative results in human intervention studies [14][15][16] and animal studies. 17,18) A possible mechanism for the anticarcinogenic potential of plant carotenoids is their antioxidant functions (scavenging free radicals and quenching singlet oxygen), which are associated with lowered DNA damage, diminished membrane lipid peroxidation and inhibition of malignant transformation in vitro.…”