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[Definitie:] "An ergogenic aid is any substance or phenomenon that enhances performance."
(Wilmore and Costill) 
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0 1 - 1 2 - 2 0 0 4 Beta-Carotene Risk Lingers After Supplement Stopped
Tue Nov 30, 2004
NEW YORK (Reuters Health) - The adverse effects of taking large quantities of beta-carotene and retinol on the rate of lung cancer and death in smokers seem to persist for years after these supplements are stopped, investigators report in the Journal of the National Cancer Institute.
In the Beta-Carotene and Retinol Efficacy Trial (CARET), researchers evaluated the effects of beta-carotene (30 milligrams) and retinol (25,000 IU) daily in people with a history of smoking or asbestos exposure. In 1996, the trial was ended early due to elevated rates of cardiovascular disease, lung cancer and death.
After the trial ended, Dr. Mark D. Thornquist, at the Fred Hutchinson Cancer Research Center in Seattle, and colleagues continued to follow CARET participants until the end of 2001.
The increased risk of lung cancer was 12 percent after the supplements were stopped compared with a 28-percent increased risk when the supplements were administered. The increased rate of death from any cause was 8 percent after the trial and 17 percent during the trial.
While the overall risks were no longer statistically significant, follow-up analysis revealed that the persistent increased risk was primarily due to increases in lung cancer risk in women.
Among the women who took the supplements, there was an increase in death rates ranging from 35 percent to 40 percent, Thornquist told Reuters Health. "I think those increases are of clinical importance."
These findings suggest different mechanisms are involved in men and women, he said. This may include hormonal effects and length of time it takes for the body to clear beta-carotene, "since beta-carotene is generally stored in fat deposits and women have a higher fat percentage on average than men." It could even be related to differences in DNA repair mechanisms, he added.
The research also highlights "the importance, once any of these trial end, to continue following these individuals," Thornquist said. "We're giving healthy individuals pharmacological doses of agents," he stressed. To think that once these supplements are stopped that they will no longer have an effect is "very short-sighted."
SOURCE: Journal of the National Cancer Institute, December 1, 2004. The Beta-Carotene and Retinol Efficacy Trial: Incidence of Lung Cancer and Cardiovascular Disease Mortality During 6-Year Follow-up After Stopping -Carotene and Retinol Supplements
Gary Goodman, Mark Thornquist, John Balmes, Mark Cullen, Frank Meyskens, Jr., Gilbert Omenn, Barbara Valanis, James Williams, Jr.
Background The Beta-Carotene and Retinol Efficacy Trial (CARET) tested the effect of daily -carotene (30 mg) and retinyl palmitate (25 000 IU) on the incidence of lung cancer, other cancers, and death in 18314 participants who were at high risk for lung cancer because of a history of smoking or asbestos exposure. CARET was stopped ahead of schedule in January 1996 because participants who were randomly assigned to receive the active intervention were found to have a 28% increase in incidence of lung cancer, a 17% increase in incidence of death and a higher rate of cardiovascular disease mortality compared with participants in the placebo group.
Methods After the intervention ended, CARET participants returned the study vitamins to their study center and provided a final blood sample. They continue to be followed annually by telephone and mail self-report. Self-reported cancer endpoints were confirmed by review of pathology reports, and death endpoints were confirmed by review of death certificates. All statistical tests were two-sided.
Results With follow-up through December 31, 2001, the post-intervention relative risks of lung cancer and all-cause mortality for the active intervention group compared with the placebo group were 1.12 (95% confidence interval [CI] = 0.97 to 1.31) and 1.08 (95% CI = 0.99 to 1.17), respectively. Smoothed relative risk curves for lung cancer incidence and all-cause mortality indicated that relative risks remained above 1.0 throughout the post-intervention follow-up. By contrast, the relative risk of cardiovascular disease mortality decreased rapidly to 1.0 after the intervention was stopped. During the post-intervention phase, females had larger relative risks of lung cancer mortality (1.33 versus 1.14; P = .36), cardiovascular disease mortality (1.44 versus 0.93; P = .03), and all-cause mortality (1.37 versus 0.98; P = .001) than males.
Conclusions The previously reported adverse effects of -carotene and retinyl palmitate on lung cancer incidence and all-cause mortality in cigarette smokers and individuals with occupational exposure to asbestos persisted after drug administration was stopped although they are no longer statistically significant. Planned subgroup analyses suggest that the excess risks of lung cancer were restricted primarily to females, and cardiovascular disease mortality primarily to females and to former smokers.
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