Criticism of the research is directed at its reliance on people reporting their own aches and pains. Some experts worry the conclusions may mean only that people of different age groups complain more or are more aware when something's wrong.

"There is some truth to it, but it's been oversold," said Dr. Arun Karlamangla, a UCLA geriatrician who lives in Thousand Oaks.

He noted that in all three age groups women reported more health problems in their 50s than men.

"We know that's not true," he said. "For a fact, we know that women are healthier than men."

The study looked only at a small portion of a baby boom that spanned from 1946 to 1964. Karlamangla predicted that a study of boomers born after 1953 would likely show their health is better because there's more emphasis on exercise and fitness.

Others say the reason some boomers may be hurting more is because they're getting bigger. National statistics show that more than 61 percent of Americans were overweight or obese last year.

"We're much fatter than we used to be," said Dr. Robert Levin, medical director of the Ventura County, Calif., Health Care Agency. "Of course we're going to see more joint pain and aches and pain."

The root cause is changes in society that devalue nutrition and fitness, Levin said. He pointed at everything from people staring at computer screens to driving to the grocery store instead of walking. Another culprit could be restaurants.

"We've become more affluent," Levin said. "As a result of our affluence, we can eat out more. We are eating food that is lesser quality than we would make ourselves in our homes and of greater quantity."