More than 4,000 chemicals make up cigarette smoke, and many of them can damage a person's health. But the bte noire of the lot is nicotine, a compound that is simultaneously pleasure-inducing, addictive, and–at high doses–poisonous. A new study adds another trait: Nicotine in mice has spawned the growth of new blood vessels and thus promoted cancer.
Blood vessel formation, or angiogenesis, can play a positive or negative role in health. Some researchers are inducing angiogenesis in heart-disease patients to help them rebuild damaged heart muscle (SN: 2/28/98, p. 132). Meanwhile, scientists fighting cancer are trying to thwart angiogenesis and
thus the flow of oxygen and nourishment to tumors.