French Team Publishes Breakthrough Study on Smoking
- Reported, November 22, 2010
Sure, smoking is bad for you -- but what happens when you combine it with
something really good -- like running eight miles a day? Do you get a healthier
smoker? Or an unhealthy athlete?
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It's one of those is-the-cigarette-half-smoked-or-half-unsmoked conundrums. And
there's no definitive answer.
"If people can quit, that's the best thing," said Dr. Robert Sallis, director of
sports medicine at Kaiser Permanente Medical Center in Fontana, Calif. That
seems obvious, but Sallis explains that many of the risks associated with
smoking are immediately and dramatically reduced upon quitting. Then he adds:
"If you can't stop smoking, exercise will mitigate some of the effects."
Lung cancer is a prime example. Although smoking increases the risk of the
disease, exercise seems to provide a protective effect. In a 2006 study
published in the journal Cancer Epidemiology Biomarkers & Prevention, women who
were current or former smokers and had high levels of physical activity were
less likely to develop lung cancer than those who were more sedentary.
"When you exercise, that improves your cardiovascular function and your HDL
cholesterol, and generally, it's just good for you," said Dr. Stanton Glantz,
professor of medicine in the division of cardiology at the University of
California, San Francisco. "So if you smoke and exercise, you're going to be
better off than if you smoke and don't exercise."
But, he adds, smoking may also hamper athletic abilities. "The balance is going
to depend on how much you smoke and how much you exercise. But I can tell you
unequivocally that people would be better marathoners if they didn't smoke."
Inhaling cigarette smoke has a number of effects on the body that can affect
performance. In the lungs, it increases tissue inflammation, narrowing airways
and allowing less oxygen to the body. Since working muscles need more oxygen,
this could result in less strength and energy during exercise.
A study examining the effects of smoking cessation found some fitness
improvements after a week. Eleven young men who smoked about a pack a day for 3
1/2 years were subjected to several tests while on a stationary bike before
quitting, and then a week later. The 2000 study, published in Medicine & Science
in Sports & Exercise, showed that pulmonary functions showed no significant
improvement, but oxygen concentration considerably increased, and exercise time
was greatly extended.
"Part of what's happening is the physical irritation" to the lungs, Glantz said.
"The industrial solvents that are in cigarette smoke -- benzene, acrolein -- and
then there's the particulate matter and the tars. You're bathing cells in
industrial-grade solvents, and it's going to reduce oxygen transport."
The effects of carbon monoxide in cigarettes while smoking and afterward take a
tremendous toll on the body, said Dr. Zab Mosenifar, medical director of the
Women's Guild Lung Institute at Cedars-Sinai Medical Center in Los Angeles. It
compromises the ability of the blood's hemoglobin to transport oxygen from the
lungs to the body, especially the muscles, during exercise.
Carbon monoxide molecules attach to hemoglobin molecules, hampering the
hemoglobin's ability to pick up oxygen from the lungs and deliver it to the
body. "This robs the muscles of extra oxygen," he said. Nicotine, Mosenifar
adds, is a vasoconstrictor, narrowing the muscular wall of blood vessels,
slowing blood flow. Over time, this can cause permanent damage to the arteries.
After years of smoking, some people may contract chronic obstructive pulmonary
disease, a combination of emphysema and chronic bronchitis that causes
irreversible lung damage and airway obstruction.
So why do some smokers who exercise say they feel little or no effect from
cigarettes? Health experts say part of it might be a degree of denial. Age, how
long they've been smoking and how much they smoke are factors. Genetics and
physiology might also play a part in how the body handles the damage from
cigarette smoke.
Lung and cardiovascular function have to be fairly compromised, Glantz said, in
order for people to notice a change: "A lot of these effects accumulate over
time," he added, and smokers may not feel them until they have tremendous
trouble breathing, or serious heart problems.
Men and women who exercise might get tired or winded sooner or feel their legs
cramp up, but if they've been smoking for a long time, and with no significant
breaks in the habit, Glantz said, they may have nothing to which they can
compare it.
The good news, he adds, is that most cardiovascular effects begin to reverse
with a few days of quitting. "So if you were to take an athlete and have them
quit for a week or two and have them do the same run again, on the average
they'd do better." Some acute effects from smoking, such as lung tissue
inflammation, can go away permanently, while others, such as cancer risks,
linger.
"Two cigarettes a day is enough to have adverse cardiovascular effects," Glantz
said. "In terms of the underlying biology, there's no question that it's
affecting their cardiovascular systems in ways that are affecting their ability
to exercise."
Mosenifar, a marathoner, doesn't buy the argument that regular exercisers can
use their healthy habits to justify their smoking. "It's like someone saying, `I
steal, but I also go to church or synagogue, so I'm doing something positive.'
They're two separate issues. People need to do some serious soul searching."
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