Non-smokers and smokers who take beta-carotene supplements are more prone to develop bladder cancer and all types of cancer respectively.

This study assessed the role beta-carotene supplements play in the prevention of cancer. Researchers systematically reviewed data obtained from 848 published articles and 6 randomized controlled trials.

The team of investigators discovered that beta-carotene supplement use was associated with high bladder cancer risk. In addition, regular intake of beta-carotene supplements was found marginally increased the odds of developing cancer among current smokers, but it had no effect on cancer prevention among non-smokers in this study. The results of this meta-analysis do not support the popular belief that frequent intake of antioxidant supplements, such as beta carotene supplements, may protect individuals against the development of various forms of cancer.