Randomized clinical trials of antioxidant supplementation have demonstrated which outcome?

Randomized clinical trials of antioxidant supplementation have demonstrated which outcome?

• A. Decreased mortality with antioxidant supplements
• B. Increased mortality with some antioxidant supplements (Vitamin A, E, beta-carotene)
• C. No effect on mortality
• D. Increased cancer risk only

Answer: (B)

The key idea is that taking antioxidant supplements in high doses does not reliably reduce mortality and can even increase it in certain groups. Large randomized trials tested supplements like beta-carotene and retinol (Vitamin A) and found harm in some populations, especially smokers. For example, trials that added beta-carotene and retinol were stopped early because they showed higher death rates and more lung cancer among high-risk individuals. Vitamin E has been studied too, with mixed results and no clear, consistent mortality benefit, but some investigations still raise concern about harm in particular contexts. Taken together, these trials show that certain antioxidant supplements can raise all-cause mortality rather than improve it, which is why the correct takeaway is that mortality was increased with some antioxidant supplements.

The key idea is that taking antioxidant supplements in high doses does not reliably reduce mortality and can even increase it in certain groups. Large randomized trials tested supplements like beta-carotene and retinol (Vitamin A) and found harm in some populations, especially smokers. For example, trials that added beta-carotene and retinol were stopped early because they showed higher death rates and more lung cancer among high-risk individuals. Vitamin E has been studied too, with mixed results and no clear, consistent mortality benefit, but some investigations still raise concern about harm in particular contexts. Taken together, these trials show that certain antioxidant supplements can raise all-cause mortality rather than improve it, which is why the correct takeaway is that mortality was increased with some antioxidant supplements.