Chewing a wad of tobacco is actually worse than smoking in terms of nicotine exposure, according to a study. Dr. Neal Benowitz, a medical professor at UC San Francisco, said his studies found chewing tobacco for half an hour exposes a person to more nicotine than smoking three cigarettes.
When ingested, nicotine can harm the cardiovascular system by raising the heart rate and blood pressure. Nicotine is also thought to cause damage to the walls of blood vessels.
Benowitz compared the nicotine levels in subjects who partook of tobacco in four forms: cigarettes, chewing tobacco, oral snuff and nicotine chewing gum. The chewing tobacco and oral snuff each exposed volunteers to more nicotine than the equivalent amount of cigarette smoke.
"This is because smokeless tobacco produces prolonged, high levels of nicotine in the blood, in contrast to the peaks and valleys that occur with cigarette smoking," said Benowitz.