ויטמינים: אינם מונעים סרטן הריאה

Am J Respir Crit Care Med. 2007 Nov 7 Supplemental Multivitamins, Vitamin C, Vitamin E, AND Folate Does Not Reduce the Risk of Lung Cancer. RATIONALE: Lung cancer is the leading cause of cancer-related mortality in the US. Although supplements are used by half the population, limited information is available about their specific effect on lung cancer risk. OBJECTIVE: To explore the association of supplemental multivitamins, vitamin C, vitamin E, AND folate with incident lung cancer. METHODS: Prospective cohort of 77,721 men AND women aged 50 - 76 years from Washington State in the VITamins AND Lifestyle VITAL study. Cases were identified through the Seattle-Puget Sound SEER cancer registry. MEASUREMENTS: Hazard ratios (HRs) for incident lung cancer according to 10 year average daily use of supplemental multivitamins, vitamin C, vitamin E, AND folate. RESULTS: 521 cases of lung cancer were identified. Adjusting for smoking, age, AND gender, there was no inverse association with any supplement. Supplemental vitamin E was associated with a small increased risk of lung cancer (HR 1.05 for every 100 mg/day increase in dose, 95% CI, 1.00 - 1.09, P = .033). This risk of supplemental vitamin E was largely confined to current smokers (HR 1.11 for every 100 mg/day increase, 95% CI, 1.03 - 1.19, P <.01) AND was greatest for non-small cell lung cancer (HR 1.07 for every 100 mg/day increase, 95% CI, 1.02 - 1.12, P = .004). CONCLUSIONS: Supplemental multivitamins, vitamin C, vitamin E, AND folate were not associated with a decreased risk of lung cancer. Supplemental vitamin E was associated with a small increased risk. Patients should be counseled against using these supplements to prevent lung cancer.

Eur J Cancer. 2007 Nov 5; Intake of antioxidant nutrients AND the risk of skin cancer. To investigate the associations between intake of antioxidant nutrients AND risk of basal cell (BCC) AND squamous cell carcinomas (SCC) of the skin, we carried out a prospective study among 1001 randomly selected adults living in an Australian community. Intake of antioxidants was estimated in 1996. Incident, histologically-confirmed BCC AND SCC were recorded between 1996 AND 2004. High dietary intake of lutein AND zeaxanthin was associated with a reduced incidence of SCC in persons who had a history of skin cancer at baseline (highest versus lowest tertile, multivariable adjusted relative risk (RR)=0.47, 95% confidence interval (CI): 0.25-0.89; P for trend=0.02). In persons without a history of skin cancer at baseline, development of BCC was positively associated with intake of vitamins C AND E from foods plus supplements (RR=3.1, 95% CI: 1.1-8.6; P for trend=0.03 AND RR=2.6, 95% CI: 1.1-6.3; P for trend=0.02, respectively). In those with a skin cancer history at baseline, dietary intake in the second tertile for beta-carotene (multivariable adjusted RR=2.2, 95% CI: 1.2-4.1) AND for vitamin E (multivariable adjusted RR=2.1, 95% CI: 1.1-3.9) was associated with increased BCC risk, with no trend, AND similar results were seen in those with a specific history of BCC. These data suggest quite different associations between antioxidant intake AND SCC compared with BCC, consistent with other evidence of their different causal pathways.