Pumpkin info for ferrets in households with second hand smoke.Ferrets, of course, are already known to be extremely sensitive to the products of tobacco smoke. Meanwhile, studies of betacarotene consumption combined with damage from smoke are somewhat mixed. In a number of situations lung malignancies actually worsen.

This abstract looks at why that can happen. Pumpkin, carrots, squash, and sweet potatoes are among the high dietary sources of beta carotene.

http://www.ncbi.nlm.nih.gov/pubmed/19638427
This information was taken from the FML.