The National Survey on Drug Use and Health found that 22 percent of men and 9 percent of women aged 50 to 64 reported binge drinking -- five or more drinks at a time -- within the last month. In this age group, "at-risk" drinking -- two or more drinks per day -- was found among 19 percent of men and 13 percent of women.

The group aged 65 and up reported binge drinking in 14 percent of men and 3 percent of women. "At-risk" drinking was found among 13 percent of men and eight percent of women in this age group.

 "A surprising number of older Americans are engaging in drinking patterns that are putting their health at risk, yet these problems often go unrecognized," said Dan G. Blazer MD, PhD, the study's lead author and JP Gibbons Professor of Psychiatry and Behavioral Sciences at Duke. "With this study we've learned that adults, especially those in their fifties, are carrying a heavier drinking burden into late life."

Blazer explained that this trend illustrates a potentially greater problem in the future as the baby boomer generation ages. He said that if their current drinking habits continue into their senior years, they could be compounding health problems that typically arise as the body's natural defenses are weakened. The negative health effects of binge drinking can range from minor injuries to more serious problems, such as stroke, cardiovascular disease, liver disease, neurological damage and poor diabetes control.

The authors propose a more rigorous use of screening for substance use and brief intervention or counseling to address the rise in alcohol use.

"Middle age and older adults may be easy to miss for at-risk or binge drinking because most clinicians are focused on excessive drinking behaviors among young people, such as those in college," Blazer said. "They also don't show the typical signs of alcohol dependence."

A nationally representative survey of nearly 11,000 men and women over 50 asked about their use of alcohol over the last year and the usual number of drinks they consumed on a drinking day during the past 30 days. The survey was conducted in 2005 and 2006. Binge drinking and at-risk drinking were defined by American Geriatrics Society Guidelines.

Other findings from the study include:

• Overall 66 percent of men and 55 percent of women reported alcohol use during the past year.
• Binge drinking was more common among those with a higher income and people who use tobacco and illicit drugs.
• Caucasian (19 percent), African-American (21 percent) and Hispanic (25 percent) men had a higher prevalence of binge drinking than other ethnic groups (14 percent).
• African-American women had a higher prevalence of binge drinking relative to Caucasian women (10 percent vs. 6 percent).
• Being separated, divorced or widowed was associated with at-risk and binge drinking among men. Non-medical use of prescription drugs was associated with binge drinking in women.

The research was supported by a grant from the National Institute on Drug Abuse. Li-Tzy Wu is the study's co-author.