In 1981, two public health research icons (Doll & Peto) hypothesized that beta-carotene (a violet to yellow plant pigment that can be converted to vitamin A by enzymes in the intestinal wall and liver) might reduce the incidence of cancer, especially lung cancer.
Since that time, other studies indicated that people who eat more fruits and vegetables rich in beta-carotene and people who have higher serum levels of beta-carotene have lower rates of lung cancer.
These studies showed it is biologically plausible that beta-carotene, as an antioxidant, may have some cancer preventative effect. Epidemiologic studies and animal bioassays of vitamin A and its analogues support the hypothesis that beta-carotene can prevent cancer.
The National Cancer Institute was so excited at this prospect that in 1988 the Beta-Carotene and Retinal Efficacy Trial (CARET) was launched to test the efficacy of beta-carotene and vitamin A in 18,314 men and women at high risk of lung cancer.
What happened? Beta-carotene was so ineffective at preventing lung cancer that the CARET trials had to be stopped 21 months early because it was determined that the beta-carotene was INCREASING lung cancer incidence and mortality!
OOPS!
The CARET researchers concluded that
Safety and efficacy should be demonstrated before recommending use of vitamin supplements in any population.Now, where are those ambulance chasers?
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Copyright © 1996 Steven J. Milloy. All rights reserved. Site developed and hosted by WestLake Solutions, Inc.