Antioxidants protect against smoke-induced lung damage
provided by American College of Nutrition
he antioxidants Vitamins C and E and Beta-Carotene at levels equivalent to that recommended in a daily diet of fruits and vegetables protected the lungs of ferrets exposed to tobacco smoke for six weeks.
Changes in the type of cell lining the lung from that of a simple one-cell layer to a multiple skin-like cell layer is a precancerous metaplasia event. Three of five ferrets exposed to tobacco smoke alone for 6 weeks developed metaplasia and it was no different (3 out of 5 animals) when vitamin C and E and a high dose of beta-carotene was added to the diet. However, only one of six animals developed metaplasia if only vitamins C and E were fed; and none of six animals developed metaplasia if a low level (equivalent to an intake of 6 mg per day) intake of beta-carotene was included along with vitamins C and E.
This preliminary research from the USDA Jean Mayer Human Nutrition Center on Aging at Tufts University was conducted by Dr. Nalinee Chongviriyaphan (nchongvicoral.tufts.edu) in cooperation with X-D Wang and R.M Russell and presented at the 42nd annual meeting of the American College of Nutrition in Orlando, FL. The results support the view that antioxidants at physiological intakes protect against the development of precancerous changes (metaplasia) of the cells lining the lung when exposed to tobacco smoke. The implication for long term smokers is that the combination of low dose beta carotene plus vitamins C and E may be protective.