Secondhand Smoke Increases Heart Risks
Accumulated data supports smoke-free environments, experts say
By Steven Reinberg
HealthDay Reporter
MONDAY, May 23 (HealthDay News) -- The average nonsmoker walking into
a smoke-filled room might not think short-term exposure to cigarette
smoke will affect them.
But a new study suggests that even small amounts of secondhand smoke
can cause life-threatening changes to a nonsmokers' circulatory
system.
And while the immediate effects of this exposure are reversed within
a few hours, exposure to secondhand smoke over longer periods of time
can have devastating consequences to the heart, including an
increased risk for heart attack, researchers warn.
"Secondhand smoke is even worse than we thought," said co-researcher
Stanton A. Glantz, a professor of medicine and longtime antismoking
advocate at the University of California, San Francisco. "It
increases the risk for an acute coronary event like a heart attack or
long-term development of atherosclerosis," he added.
Chronic exposure to secondhand smoke is about 80 percent as
deleterious to health as being a pack-a-day smoker, Glantz said. "The
cardiovascular system is exquisitely sensitive to the toxins of
secondhand cigarette smoke. Most of the toxic effects of secondhand
smoke occur within five minutes of exposure," he noted.
In their study, Glantz and his colleague Dr. Joaquin Barnoya, an
assistant adjunct professor of epidemiology at UCSF, reviewed the
existing medical literature on the effects of secondhand smoke on the
cardiovascular system. They looked at 29 studies published since 1995
that compared the effects of secondhand smoke with the effects of
active smoking.
Their report appears in the May 24 issue of Circulation.
Glantz and Barnoya found there is sufficient evidence that key
aspects of cardiovascular function, including clotting, the ability
of blood vessels to change size, arterial stiffness, atherosclerosis,
oxidative stress, inflammation, heart rate variability, energy
metabolism, and severity of heart attack are all sensitive to toxins
found in secondhand smoke.
"The effects of even brief (minutes to hours) passive smoking are
often nearly as large (averaging 80 percent to 90 percent) as chronic
active smoking," they wrote.
"It doesn't take much to cause big effects," Glantz said. "If you
already have compromised coronary circulation and go into a smoky
environment, there is a substantial increase in your risk of an acute
event."
Barnoya believes the findings belie what the tobacco industry would
have people believe. "The arguments from the tobacco industry have
been that it is not likely that you can find such large effects in
passive smokers, given the dose they get compared with the dose an
active smoker gets," he explained.
But nonsmokers are more sensitive to the effect of tobacco smoke than
are active smokers, Barnoya said. "In some cases, the effects are as
large or even larger than you see in an active smoker."
The dangers of secondhand smoke are so great that Barnoya believes
everyone should avoid it. "We should be fighting for smoke-free
environments," he stressed.
Other experts not involved in the study are unanimous in their
agreement of the dangers of secondhand smoke.
"Secondhand smoke disables and kills many people by virtue of its
cardiovascular effects and also by virtue of its effects on the
lung," said Dr. Norman H. Edelman, chief medical officer for the
American Lung Association.
Another expert sees secondhand smoke as an assault on the health of
nonsmokers. "How can any society allow tobacco smoke to be imposed on
innocent bystanders?" asked Dr. David L. Katz, an associate clinical
professor of public health and director of the Prevention Research
Center at Yale University School of Medicine.
"We have clear, convincing evidence that those who smoke are swinging
a big stick indeed at the noses of those of us who don't," Katz
said. "While they should have autonomy over their choices, they
should not have autonomy over ours. Smoking in public places does not
stop where my nose begins and therefore, it should be banned. Not
just by some states, but by all. This study will, I hope, help
cultivate the political will to see that job is done sooner rather
than later."
Requests for a response from cigarette maker Philip Morris Inc., were
not answered at press time.
More information
The American Heart Association can tell you more about the dangers of
secondhand smoke.
SOURCES: Stanton A. Glantz, Ph.D., professor of medicine, University
of California, San Francisco; Joaquin Barnoya, M.D. M.P.H., assistant
adjunct professor, epidemiology, University of California, San
Francisco, and director, cardiovascular research, Unidad de Cirugia
Cardiovascular de Guatemala, Guatemala City; Norman H. Edelman, M.D.,
vice president, Health Sciences Center, dean, School of Medicine,
Stony Brook University, New York, and chief medical officer, American
Lung Association; David L. Katz, M.D., M.P.H., associate clinical
professor, public health, and director, Prevention Research Center,
Yale University School of Medicine, New Haven, Conn.; May 24, 2005,
Circulation
Last Updated: May 23, 2005
Copyright © 2005 ScoutNews LLC. All rights reserved.