beta carotene increases mortality

From: Doug Skrecky (oberon@vcn.bc.ca)
Date: Fri Jun 04 1999 - 07:30:18 MDT


Citations: 1-2
<1>
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]

<2>
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.



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