This is the most critical safety distinction between the two formulas. Beta-carotene in the original AREDS formula was shown to nearly double the risk of lung cancer in former smokers. In the AREDS trial, lung cancer occurred in approximately 2 percent of participants taking beta-carotene, compared to about 0.9 percent in those who did not. The overwhelming majority of those who developed lung cancer were former smokers.
Both current and former smokers must take only the AREDS2 formula. There is no circumstance in which the original beta-carotene formula is considered safe for anyone with a history of smoking.