The analysis also found that significant
health disparities exist between racial groups, and that
Americans are less likely to have access to health care when
they reach adulthood than they did during the teenage years.
The analysis appears in the January 2006
Archives of Pediatrics and Adolescent Medicine and was
conducted by researchers at the Carolina Population Center
and the University of North Carolina at Chapel Hill.
"Smoking, obesity, and alcohol abuse are
leading contributors to preventable death in the United
States," said Duane Alexander, M.D., director of the
National Institute of Child Health and Human Development,
the NIH Institute that funded the analysis. "By early
adulthood, a large proportion of Americans smoke, are
overweight, and drink alcohol to excess."
Principal investigator Kathleen Mullan
Harris, Ph.D., and her colleagues of the Carolina Population
Center and the University of North Carolina at Chapel Hill,
conducted their analysis using data from the National
Longitudinal Study of Adolescent Health.
The National Longitudinal Study of
Adolescent Health was designed to measure the effects of
home, family, and school environment on behaviors that
promote health. The study was undertaken in response to a
mandate by Congress. Funding for the survey was provided by
a grant from the NICHD with contributions from 17 other
"When they were young teenagers, most of
the participants had fairly healthy behaviors," said
Christine Bachrach, Ph.D., Chief of NICHD's Demographic and
Behavioral Sciences Branch and project officer for the
study. "What's really alarming is how rapidly healthy
practices declined by the time the participants reached
For the current analysis, the researchers
analyzed the responses of a nationally representative sample
of more than 14,000 young adults who have been followed
since early adolescence. The survey respondents, recruited
from high schools and middle schools around the country,
were first interviewed from 1994 to 1995, when they ranged
from 12 to 19 years of age, and again in 2001 and 2002, when
they were 19 to 26 years old.
The survey participants responded to
questions on diet, inactivity, obesity, tobacco use,
substance use, binge drinking, violence, reproductive
health, mental health, and access to health care.
For nearly all groups surveyed, diet,
activity level, obesity, health care access, tobacco,
alcohol and illicit drug use, and likelihood of acquiring a
sexually transmitted disease worsened as the youth reached
adulthood, Dr. Harris said.
"These trends are quite stunning," Dr.
Harris added. "Whether or not the trends will continue as
they age, we don't know. But it doesn't bode well for their
future health, especially if these habits become
By the time they had reached adulthood,
Dr. Harris explained, the participants were more likely to
be obese, to frequently eat fast food, and to be sedentary.
They were also less likely to have health insurance, to
receive health care when they needed it, or to receive
regular dental and physical health examinations.
The authors reported "dramatic" increases
in behaviors related to 3 leading contributors to
preventable deaths. "These findings underscore the
importance of ongoing preventive efforts related to smoking,
poor diet and physical inactivity, and alcohol consumption,
early in the life course."
For example, among young white women, the
proportion reporting no weekly physical exercise was 5
percent during the adolescent years, but was 46 percent in
early adulthood. Similarly, among white males, the
proportion that was obese grew from 14 percent in the teen
years to 19 percent when they became adults.
The researchers added that the decline in
health care coverage resulted from young adults leaving
their parents' health insurance or Medicaid coverage as they
reached legal age.
On the positive side, participants were
less likely to experience feelings of depression at
adulthood than when they were adolescents, less likely to
have suicidal thoughts, and less likely to be victims or
perpetrators of violence.
For most of the indicators, Asians and
whites were at lowest risk, while blacks and Native
Americans were at highest risk. Racial and ethnic
disparities in health as well as in access to health care
also increased as the participants reached adulthood. No
single racial or ethnic group, however, had a greater
overall risk profile than any other group.
Whites, for example, were healthier during
earlier adolescence than most other groups, but experienced
the greatest declines upon reaching adulthood. By the time
they reached adulthood, whites had the highest rates of
smoking (31 percent for males, 28 percent for females) and
white males had the highest rate of binge drinking (67
At adulthood, blacks were the least likely
to smoke cigarettes (13 percent for males, 8 percent for
females) to binge drink (33 percent for males, 15 percent
for females) or to use hard drugs (5 percent for males, 2
percent for females). When they were adults, blacks (18
percent) and Native Americans (16 percent) were more likely
to develop asthma than were other groups.
Among female adults, blacks (55 percent)
and Asians (53 percent) were the least likely to exercise,
and among males, white and blacks were the least likely to
Dr. Harris explained that she and her
coworkers are now doing additional research on the data in
the Adolescent Health study to determine why certain groups
were more at risk for a particular unhealthy behavior than
other groups. She added, however, that because the groups
differed in their health behaviors, intervention programs to
reduce unhealthy behaviors would likely have the greatest
chances for success if they were individually tailored to
meet the needs of each particular group.
"The variability in health disparities
among groups also implies that no one overall solution will
work to reduce disparities, but approaches specific to each
health outcome are needed," Dr. Harris said
The NICHD is part of the National
Institutes of Health (NIH), the biomedical research arm of
the federal government. NIH is an agency of the U.S.
Department of Health and Human Services. The NICHD sponsors
research on development, before and after birth; maternal,
child, and family health; reproductive biology and
population issues; and medical rehabilitation.