Dangerous illusions. The illusion that nothing bad can happen and that life will go on forever seems to be particularly strong among teenagers, and recent research by Ralph Hingson, a School of Public Health professor, reveals that those who begin drinking heavily at an early age, before they reach 13, have a heightened sense of invulnerability that may lead to serious risk-taking behavior later on.

Hingson and his colleagues analyzed information from the 1999 Harvard College Alcohol Survey, which included a random sample of undergraduates from 119 schools. They found that those who first become drunk before age 13 were eight times more likely to erroneously believe that they could consume five or more drinks and drive safely and legally than those who first became drunk at age 19 or older. They were also four times as likely to drive after five or more drinks, to be alcohol-dependent, and to be seriously injured within six hours of drinking. Similarly, early drinkers were more likely to report unplanned and unprotected sex after drinking than their contemporaries who began drinking later.

Hingson’s earlier studies had revealed that people who started drinking at an earlier age drink heavily with greater frequency and have a greater likelihood of experiencing alcohol-related unintentional injuries, motor-vehicle crashes, and physical fights during both adolescence and adulthood.

This study found that enormous suffering results from early-age drinking and associated behaviors. According to Hingson, each year more than two million college students aged 18 to 24 drive after drinking, more than three million ride with drunk drivers, more than half a million are injured after drinking, and 1,400 die from alcohol-related injuries, most in traffic crashes. And these figures take into account only the drinkers themselves, not the other lives affected. In another study last year, Hingson reported that more than 600,000 college students are assaulted annually by other college students who have been drinking, and that more than 70,000 reported date rapes each year by college students are associated with drinking.

“Early prevention and intervention are critical to reaching young people,” says Hingson. “It is essential that we expand clinical, educational, legal, and community interventions to reduce drinking among adolescents and delay onset of first drunkenness. Because drinking behaviors that contribute to alcohol problems among college students often begin even before students enter college, colleges and the communities in which they are located need to work together to address these problems.”

Urban environmental impact. People who live in sprawling metropolitan areas are more likely to be obese, according to a new study by Russell Lopez (SPH’03), a research associate at the School of Public Health. Obesity, Lopez notes, takes a tremendous toll on people’s health, costing the U.S. economy billions of dollars. If obesity continues to increase at its present rate, 40 percent of Americans will be obese by 2010 -- presenting a major public health problem.

Urban sprawl occurs in many U.S metropolitan areas, but is often loosely defined. The Lopez study defines sprawl as an overall pattern of development across a metropolitan area that places a large percentage of the population in lower density residential areas. Lopez and H. Patricia Hynes, an SPH professor of environmental health, had previously developed a sprawl index, a procedure that assigns a number (on a scale from 1 to 100) to an urban area based on population density data derived from the U.S. census.

Lopez examined the association between the sprall index and data from the 2000 Behavioral Risk Factor Surveillance System, a national telephone survey of adults that inquired about health and lifestyle issues. Even controlling for differences that might occur from variations in gender, age, race or ethnicity, income, and education, Lopez found that for each one point rise in the sprawl index, the risk of being obese increased by half a percent -- about the same effect that advancing age has on the probability of increasing obesity.

He hypothsizes that sprawl may increase the risk of obesity by encouraging driving and discouraging walking and biking. He attributes increasing sprall to factors such as affluence, which enables families to purchase larger houses on larger lots, cultural values that reject urban living and emphasize automobile use, inexpensive land values, and government policies such as zoning laws.

“Americans moved to the suburbs at least in part because they wanted to live in more healthy communities,” Lopez says. “But this study suggests that low-density, suburban-type development may have a negative impact on health. Public health advocates do not traditionally get involved in zoning, development, and land use issues, but perhaps they need to work to make communities more healthy by promoting urban designs that promote physical activity.”

The study will be published in the March 2004 edition of the American Journal of Public Health.