Researchers also advise people to avoid smoky areas

Eating more fruits and vegetables offers yet another health benefit: It can counteract the damaging effects of environmental cigarette smoke, a group of UA researchers found.

Sidestream smoke - smoke that is emitted from a burning cigarette but has not been inhaled- is a particularly dangerous environmental hazard. It can cause severe cell damage by increasing the amount of oxidants in the body, which can damage the immune system and remove necessary vitamins.

But recent research at the University of Arizona College of Public Health shows that increasing the amount of antioxidants in the diet can significantly reduce the damage caused by sidestream smoke.

"It may come as no surprise that tobacco smoke is not good for you," said College of Public Health Professor Ronald R. Watson. "But there are things you ought to do if you are exposed to smoke to reduce the damage."

Reducing the damage, it turns out, is as simple as upping the intake of fruits and vegetables, which naturally contain high amounts of antioxidants like beta carotene, magnesium and zinc.

According to The American Cancer Society, most Americans eat fewer than the recommended serving of five a day.

Typically, smokers eat fewer fruits and vegetables than the average person, Watson said.

"It's very hard to get people to change their habits," he said "But this is something that is easy and relatively inexpensive."

The study was conducted throughout several months using mice. The mice were exposed to a burning cigarette from periods as short as 15 minutes to as long as two hours a day. The researchers found that the longer the mice were exposed to smoke, the more damage they showed, and that it did not require a significant amount of time for the damage to appear.

The mice treated with antioxidants - in the form of vitamin supplements - were harmed less by the smoke.

"The implication here is if there is significant damage after four months in the mice then it doesn't take very long," Watson said. "You can't feel it, but there is damage to your tissues."

A person who lives with a smoker or works somewhere that allows smoking may be exposed to sidestream smoke.

"Sidestream smoke is more dangerous pound per pound than what a smoker gets," Watson said. "A smoker's quantity is higher, but the toxicity is higher in sidestream smoke."

Almost everyone is exposed to environmental cigarette smoke, Watson said, but there are things people can do to reduce the damage.

"You do have some control over smoking exposure," he said. "The best thing is not to go places where smoking is allowed."

"If you can't avoid smoke, then the second best choice is to increase your consumption of fruits and vegetables. The third choice is to take supplements," Watson added.

It is already known that smoking causes lung and heart damage, said research assistant Jin Zhang. But it is "important to educate people that passive smoking (indirect exposure) is also dangerous to human health, and for nonsmokers to reduce their exposure."

Even though a person may not even feel differently after being exposed to sidestream smoke, it's important to be aware of its consequences, Watson said. "Over 30,000 people will die this year in the United States because of other people's tobacco smoke."