Smoking during the teenage years stunts lung growth and accelerates the decline in their function that inevitably comes with age. At the same time, the habit damages blood vessels in ways that can later lead to a heart attack, stroke and aortic rupture.
Those are among the conclusions of a report by the U.S. Surgeon General on tobacco use by young people. The 899-page document gathers recent research on the epidemiology, effects and strategies to fight youth smoking.
The last such report, in 1994, spurred a public health campaign that caused a marked drop in teenage smoking, especially after 1998. Since 2007, however, that trend has leveled off, and tobacco use is now increasing in some groups and categories. For example, smokeless tobacco use is up among white high school-age boys, and cigar smoking appears to be rising among black high school girls.
“Two people start smoking for every one who dies from the habit each year,” Surgeon General Regina M. Benjamin said. “Almost 90 percent of those ‘replacement smokers’ first try tobacco before they are 18.”
Among the more remarkable findings in the report is how early and measurably smoking damages the youthful body, even if its owner doesn’t feel it.
A study of nearly 700 children from East Boston found that those who started to smoke at age 15 exhaled 8 percent less air in one second — a key measure of lung function — than non-smoking teenagers. The growth of lung capacity stopped a year earlier in smokers — at 17 in girls and 19 in boys — than in non-smokers.
Lung function usually doesn’t begin to decline until after age 45 in men. In those who started smoking as teenagers and kept at it, that change began almost 15 years earlier.
Other studies, involving black U.S. teenagers, Dutch adolescents followed for 15 years and Danish children with asthma, also showed damaging effects of smoking on lung function.
Early smoking also affects the cardiovascular system.
Researchers reviewed autopsy results for white men ages 25 to 34 killed by trauma or homicide and found smokers were twice as likely to have advanced damage (“atherosclerosis”) of the abdominal aorta as non-smokers. They also had somewhat greater damage to the blood vessel most often implicated in acute heart attacks.
“This .?.?. profile of risk suggests that the effect of tobacco smoking begins at a young age and is cumulative,” the authors wrote.
The perceived and actual effect of smoking on weight has also been the subject of research.
A study of 1,800 college students in 2001 found that 4 percent of female smokers and 1 percent of male smokers cited weight control as the main reason for their habits. In a survey of 81,000 Minnesota high school students, nearly half the girls who smoked, and more than a quarter of the boys who did, cited weight control as one of the reasons.
Research that followed teenagers over seven years found that starting smoking had no effect on the weight of whites, and reduced final weight only slightly in blacks, compared with non-smokers. There’s no question, however, that people tend to gain weight when they quit. In a study of 5,100 people ages 18 to 30 who were observed for seven years, whites who quit gained 9 pounds and blacks who quit gained 15.
Smoking by high school students has declined significantly over the past 35 years. In 1976, 35 percent of high school senior boys and 38 percent of girls had smoked a cigarette in the previous month. In 2007, that was down to 26 percent and 24 percent, respectively. In blacks, the drop has been especially dramatic — 33 percent to 14 percent for boys and 34 percent to 9 percent for girls.
(The rate goes up after high school. Nearly one-third of people ages 18 to 24 smoke, compared with one-fifth older than 24.) the entire article at source