Secondhand Smoke Invades Your Blood
FRIDAY, Dec. 1 (HealthScout) -- If you thought dirty ashtrays and smelly drapes were the worst thing about living with a smoker, listen up.
Your partner's nasty habit could cause you to experience a serious depletion of some key nutrients necessary for good health, claims new research.
Regular exposure to secondhand smoke causes a decrease in specific antioxidants -- micronutrients that help fortify the body against damage that eventually can lead to cancer and heart disease, report researchers from the Johns Hopkins School of Public Health.
"This issue has been looked at before, but there has been very limited data about blood levels of micronutrients, plus the previous studies tended to be small or limited in exposure," says study author Albert Alberg, an assistant professor of epidemiology at Johns Hopkins. "This is the first large-scale study with good data on household exposure to smoking to show this association."
The researchers analyzed some 1,500 blood samples taken from residents of Washington County, Maryland, in 1974 and also reviewed a smoking survey of the same residents conducted in 1975. The blood was analyzed for levels of vitamins A and E and a variety of carotenoids, including alpha and beta carotene, as well as lutien, lycopene, zeaxanthin and cryptoxanthin -- all antioxidants that help fight free radical damage, which is the cell destruction that leads to disease.
For comparison, participants were divided into three groups: smokers, nonsmokers living with smokers and nonsmokers with no exposure to cigarettes at home.
The end result: Both the smokers and those exposed to their smoke had measurably lower levels of certain carotenoids, particularly alpha and beta carotene and cryptoxanthin, the study says.
Conversely, the researchers found that levels of both vitamins A and E and the remaining carotenoids were not depleted in either the smokers or those exposed to their smoke. Findings appear in the December issue of the American Journal of Clinical Nutrition.
"The patterns that have been observed in relation to passive smoking involve the same micronutrients that you see with active smoking," Alberg says. "It's like the same fingerprint left by smokers, and it helps verify that the associations are true."
Other experts are quick to agree.
"Even though you're not actively sucking on the cigarette, you're still breathing in the same smoke -- maybe not as concentrated, but you're still breathing it in -- so it's going to have the same effect chemically on your body, just at a lesser intensity," says Samantha Heller, senior clinical nutritionist at New York University Medical Center.
While no one is certain just why these particular micronutrients are affected by the smoke, while others are not, Heller says it may well be that these are the factors called into play to defend the body against the chemicals found in cigarettes.
"It seems possible that these particular carotenoids are the ones that are depleted as they try to defend the body against free radical damage that is occurring as a result of the smoke," she says.
It's no secret that tobacco companies have been fighting vigorously any suggested link between smoking and ill health -- often using the argument that studies don't control for other lifestyle factors, such as diet.
One of the reasons this new study is so important, medical experts say, is because it helps strengthen the direct link between smoking and disease.
"What we have learned here raises the idea that the effects of smoking are more complex than we realized," Alberg says. "And, if the associations we observed prove true, it kind of creates a pathway for how the disease process occurs -- and it's linked directly to smoking."
What To Do
In the event that you're exposed to secondhand smoke, either where you work or at home, experts recommend trying to counteract some of the potential damage by improving your diet.
"Eat as healthy as you can -- sticking to a diet high in fruits and vegetables and legumes and grains and all the foods that we know contain the antioxidants that are being depleted," Heller says. Because foods work as a team, she says, they may be more helpful than simply taking an antioxidant supplement.
Alberg agrees. "My first recommendation would, of course, be to avoid passive smoke as much as possible," he says. "But, if that's not possible, the second line of defense would be to definitely increase your intake of fruits and vegetables."
As for vitamin supplements, he thinks that research is too preliminary to suggest they can help.
"We simply don't know yet if taking a supplement is going to do the same good as eating foods high in antioxidants, particularly the carotenoids," Alberg says.
Foods high in the carotenoids depleted by cigarette smoke include green and yellow vegetables -- such as broccoli, yellow squash, carrots and cantaloupe -- and citrus fruits. The carotenoid cryptoxanthin can be found in tangerines, oranges and peaches.