While studying the relationship between vitamin A and lung inflammation, researchers at Kansas State University made a surprising discovery — they found a link between vitamin A, cigarette smoke and emphysema, a lung disease found primarily in smokers. Richard Baybutt, associate professor of Human Nutrition, said the discovery was accidental, but that given its implications, they quickly shifted their investigative focus.

Vitamin A, found in such foods as dairy products, eggs, liver and oily fish, is important for proper cell development and growth as well as immune health. Vitamin A is also obtained from plant foods that contain beta-carotene, particularly green and orange fruits and vegetables such as broccoli, spinach, apricots and peaches.

In a previous study, the researchers found that rats fed a vitamin A-deficient diet developed emphysema. In their most recent study, they exposed a group of rats to cigarette smoke. The rats then became vitamin A deficient. The researchers said benzopyrene, a carcinogen found in cigarettes, was the link, and when fed to rats, could actually induce vitamin A deficiency.

The researchers theorized that smokers develop emphysema because of a vitamin A deficiency. To further study the connection, they began feeding the rats exposed to cigarette smoke a diet rich in vitamin A. The researchers found that the emphysema was effectively reduced, leading them to conclude that diet—particularly vitamin A intake may in part explain why some smokers’ lungs suffer more from the effects of cigarette smoke than others.

Since vitamin A has also been associated with lower cancer risk, Baybutt and his team now hope to investigate the link between vitamin A and lung cancer.

Source: Kansas State University, Jul 26, 2004