Drinking is harmful to your health at any age. But as you get older, the risks become greater — even with the same amount of drinks.

Alcohol affects “virtually every organ system in the body,” including the muscles and blood vessels, digestive system, heart and brain, said Sara Jo Nixon, the director of the Center for Addiction Research & Education at the University of Florida. “It particularly impacts older adults, because there’s already some decline or impact in those areas.”

“There’s a whole different set” of health risk factors for older drinkers, said Paul Sacco, a professor of social work at the University of Maryland, Baltimore who studies substance use and aging. People might not realize that the drinks they used to tolerate well are now affecting their brains and bodies differently, he said.

Alcohol can present new problems in older age — particularly at 65 and up — for even light or occasional drinkers. Older adults tend to have less muscle mass and retain less water in their tissues compared with younger people, which can increase blood alcohol concentration, said Aaron White, a senior advisor at the National Institute on Alcohol Abuse and Alcoholism. This means it takes fewer drinks for older people to feel intoxicated, and heightens the risk of severe injury from falls.

According to Dr. Nixon’s research, older people also show deficits in working memory at lower blood alcohol concentrations than younger drinkers. In another study Dr. Nixon worked on, some older adults in driving simulations showed signs of impairment after less than one drink.

Drinking alcohol can increase the risk of developing chronic conditions like dementia, diabetes, cancer, hypertension and heart disease. But it can also worsen outcomes for the majority of older adults already living with chronic disease, said Aryn Phillips, an assistant professor of health policy and administration at the University of Illinois Chicago who studies alcohol and aging.