So when they say "increases mortality" they mean that the experimental subjects live longer?
Doug Skrecky wrote:
>
> 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.