beta carotene increases mortality

Doug Skrecky (oberon@vcn.bc.ca)
Fri, 4 Jun 1999 06:30:18 -0700 (PDT)

Citations: 1-2
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Authors
Omenn GS.
Institution
School of Public Health & Community Medicine, University of Washington, Seattle 98195-7230, USA. gomenn@umich.edu Title
Chemoprevention of lung cancer: the rise and demise of beta-carotene. [Review] [124 refs]
Source
Annual Review of Public Health. 19:73-99, 1998. Abstract
Beta-carotene and retinoids were the most promising agents against common cancers when the National Cancer Institute mounted a substantial program of population-based trials in the early 1980s. Both major lung cancer chemoprevention trials not only showed no benefit, but had significant increases in lung cancer incidence and in cardiovascular and total mortality. A new generation of laboratory research has been stimulated. Rational public health recommendations at this time include:

  1. Five-A-Day servings of fruits and vegetables, a doubling of current mean intake; 2. systematic investigation of the covariates of extremes of fruit and vegetable intake; 3. discouragement of beta-carotene supplement use, due to adverse effects in smokers and no evidence of benefit in non-smokers; 4. multilevel research to develop and evaluate candidate chemoprevention agents to prevent lung and other common cancers; and 5. continued priority for smoking prevention, smoking cessation, and avoidance of known carcinogens in the environment. [References: 124]

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Authors
Heinonen OP. Albanes D. Virtamo J. Taylor PR. Huttunen JK. Hartman AM. Haapakoski J. Malila N. Rautalahti M. Ripatti S. Maenpaa H. Teerenhovi L. Koss L. Virolainen M. Edwards BK. Institution
Department of Public Health, University of Helsinki, Finland. Title
Prostate cancer and supplementation with alpha-tocopherol and beta-carotene: incidence and
mortality in a controlled trial [see comments]. Comments
Comment in: J Natl Cancer Inst 1998 Mar 18;90(6):414-5, Comment in: J Natl Cancer Inst 1998 Mar 18;90(6):416-7
Source
Journal of the National Cancer Institute. 90(6):440-6, 1998 Mar 18. Abstract
BACKGROUND: Epidemiologic studies have suggested that vitamin E and beta-carotene may each influence the
development of prostate cancer. In the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, a controlled trial, we studied the effect of alpha-tocopherol (a form of vitamin E) and beta-carotene
supplementation, separately or together, on prostate cancer in male smokers. METHODS: A total of 29133 male smokers aged 50-69 years from southwestern Finland were randomly assigned to receive alpha-tocopherol (50 mg), beta-carotene (20 mg), both agents, or placebo daily for 5-8 years (median, 6.1 years). The supplementation effects were estimated by a proportional hazards model, and two-sided P values were calculated. RESULTS: We found 246 new cases of and 62 deaths from prostate cancer during the follow-up period. A 32% decrease (95% confidence interval [CI] = -47% to -12%) in the incidence of prostate cancer was observed among the subjects receiving alpha-tocopherol (n = 14564) compared with those not receiving it (n = 14569). The reduction was evident in clinical prostate cancer but not in latent cancer. Mortality from prostate cancer was 41% lower (95% CI = -65% to -1%) among men receiving alpha-tocopherol. Among subjects receiving beta-carotene (n = 14560), prostate cancer incidence was 23% higher (95% CI = -4%-59%) and mortality was 15% higher (95% CI = -30%-89%) compared with those not receiving it (n = 14573). Neither agent had any effect on the time interval between diagnosis and death. CONCLUSIONS: Long-term supplementation with alpha-tocopherol substantially reduced prostate cancer incidence and mortality in male smokers. Other controlled trials are required to confirm the findings.