Secondhand Smoke Hurts Heart Like Smoking
Even Minutes and Hours of Exposure Count, Say Researchers
Brief Exposure Can Have an Impact
Secondhand smoke may register on the heart in a short time, the review shows.
"The effects of even brief (minutes to hours) passive smoking are often nearly as large (averaging 80% to 90%) as chronic active smoking," says the review.
For instance, one study exposed 12 men to six hours of secondhand smoke -- about what someone might get from an evening in a smoky bar. For the next 24 hours, the men's levels of HDL "good" cholesterol were significantly lower than before the experiment.
In another study, healthy men breathed secondhand smoke from 15 cigarettes for an hour in an unventilated room. During that hour, the men had a significant increase in aortic arterial stiffness -- an early marker of blood vessel wall abnormalities that increases heart disease risk.
The stiffness started after just 15 minutes, then hit and maintained its peak at 30 minutes.
Antioxidant supplements might help replenish antioxidant levels lowered by secondhand smoke, says the review.
However, that "probably will not prevent the [heart] damage associated with secondhand smoke because such supplements do not seem to reduce the risk of heart disease in general," say the researchers.
Quitting smoking and limiting exposure to secondhand smoke may help your health. Smoking has been tied to many other health problems besides heart disease, including cancer, erectile dysfunction, sudden infant death syndrome (SIDS), asthma, infertility, and problems in pregnancies.
Mechanisms May Work Together
The mechanisms behind secondhand smoke's heart damage may gang up, egging each other on to raise heart disease risk, write Barnoya and colleagues.
Barnoya worked on the review while on staff at the University of California, San Francisco. Now, he works at the Unidad de Cirugía Cardiovascular de Guatemala.