Prospective study of vitamins C, E, and A and carotenoids and risk of oral premalignant lesions in men

Abstract

Case-control studies indicate that vitamins C, E, A and carotenoids decrease risk of oral premalignant lesions (OPLs) and oral cancer, but clinical trials have failed to find protective effects of bcarotene and suggest that vitamin E may increase risk. The authors prospectively evaluated the association between intake of vitamins C, E, A and carotenoids and incidence of OPL. Participants were 42,340 men in the Health Professionals Follow-up Study who provided information on supplement use and diet every 2-4 years by food frequency questionnaire. The authors confirmed 207 clinically or histopathologically diagnosed OPL events occurring between 1986 and 2002 by medical record review. Multivariate-adjusted relative risks (RR) of OPL were calculated with proportional hazards models. Total intake of vitamin C, vitamin A or carotenoids was not significantly associated with OPL risk. Dietary vitamin C was significantly associated with reduced risk (quintile 5 vs. 1, RR 5 0.52, 95% CI 0.31-0.85, p trend 5 0.04), but no association with supplemental vitamin C was observed. Inverse associations were apparent for b-cryptoxanthin and a-carotene intake. No clear relationship emerged with b-carotene, lycopene or lutein/zeaxanthin. Vitamin E was associated with increased risk (quintile 5 vs. 1, RR 5 1.86, 95% CI 1.06-3.19), particularly among current smokers and with supplemental intake (currentsmokers, supplement dose tertile 3 vs. 1, RR 5 3.07, 95% CI 1.28-7.34, p trend 5 0.01). For current smokers, b-carotene also increased risk. Vitamin C from dietary sources, but not supplements, was associated with a reduced risk of OPL. The observed increased risk for current smokers with high vitamin E or b-carotene intake should be explored further. ' 2006 Wiley-Liss, Inc.Key words: leukoplakia; vitamin C; vitamin E; mouth neoplasms; diet A prominent contributor to the onset and development of oral cancer is damage to DNA and other cellular molecules by reactive oxygen species. Tobacco use, the primary known risk factor for oral cancer and precancerous lesions, also increases oxidative stress and therefore enhances the possibility of cancer-causing mutations, oxidization of lipids and proteins and alteration of signal transduction pathways that damage cells.1,2 Dietary micronutrients, such as vitamin E, vitamin C, b-carotene and lycopene, have potential chemopreventive properties that can neutralize or block reactive oxygen species and protect against cellular damage. 3-5Observational studies suggest that intake of antioxidants, primarily through consumption of fruits and vegetables, is associated with a decreased risk of oral cancer, but the evidence has been inconsistent. [6][7][8][9][10][11] Recent large clinical trials, however, saw significantly increased risks of head and neck cancer recurrence and second primary tumors with a-tocopherol (vitamin E) supplementation, 12 and failed to find any benefits of supplementation with vitamin A in oral cancer patients. 13 Such results suggest that more compelling evidence is needed before...

Adaptive Cellular Stress Pathways as Therapeutic Targets of Dietary Phytochemicals: Focus on the Nervous System

“…Moreover, the emerging evidence suggests that very high doses of antioxidant vitamins may not be beneficial for health and might even be harmful. Indeed, clinical trials of vitamins E, C, and A have failed in patients with a range of disorders (Hasnain and Mooradian, 2004;Block et al, 2007;Canter et al, 2007;Maserejian et al, 2007;Galasko et al, 2012).…”

Multitargeted therapy of cancer by lycopene

“…For example, in other studies of the participants in the Health Professsionals Follow-up Study, no association was observed between lycopene intake and the risk of oral premalignant lesions [69] or between tomato consumption and the risk of bladder cancer [70]. In a pooled analysis of food frequency questionnaires from 11 cohort studies including more than 700,000 participants and 7,885 incident cases of colorectal cancer, tomato consumption was found to provide no reduction in the risk of colorectal cancer [71].…”

Carotenoids in Green Vegetables and Health Aspects

“…Further, some research has linked the consumption of lutein and zeaxanthin to reducing the risk for lung and breast cancer, although results are inconsistent [18,40]. The relationship between vitamins, carotenoid intake, and oral cancer risk has been studied [41]. Using dietary intake data from 42,340 men in the Health Professionals Follow-up Study, researchers determined the risk for oral premalignant lesions related to intake of vitamins A, C, and E, and carotenoids from food or dietary supplements.…”