Not a day goes by without some report on the graying of America. With 72 million baby boomers marching in step toward old age, it's hard not to notice the impact.

In the next 20 years, the percentage of the population over age 65 will increase from 12 percent to 20 percent, but, most importantly, those over 85 will almost triple in number.

The biggest threat to our health care system is not cancer, heart disease and diabetes, but rather the high prevalence of physical or cognitive disabilities in Americans over 85, which makes them dependent on others and no longer able to live alone.

Currently, 50 percent of 85-year-old adults will be physically or cognitively dependent. This leads to huge increases in health care costs and overwhelming burdens on families, friends and communities.

The only real hope to fend off a true health crisis is to reduce the risk of disability for the millions of baby boomers who will utilize more and more health resources as they age. Unfortunately, in a recent study published by the American Journal of Public Health, researchers found that baby boomers are much more likely to be disabled than their parents. Although it is the overwhelming increase in the prevalence of obesity that has covered the news and seemed the harbinger of our future health problems, the disability "epidemic" could prove a much greater threat.

In this study, researchers from the University of California at Los Angeles examined changes in disability levels in adults 60 and older who participated in the National Health and Nutrition Examination Surveys in 1988 to 1999. Researchers identified the percentage of the people who had impaired activities of daily living, which included an inability to use the restroom, dress, groom, bathe or feed themselves.

They also looked for impaired instrumental activities of daily living that included the ability to do household chores, shop, drive, use the telephone and prepare meals. Finally, researchers examined the ability of individuals to walk a quarter of a mile without stopping, climbing 10 steps and stooping, crouching and kneeling.

Incredibly, between 1988 and 1999, disability among people in their 60s increased by 40 percent to 70 percent in every area that was studied. At the same time, adults in their 70s stayed the same while the level of disabilities for 80-year-olds actually improved.

Breaking down the numbers further, the percentage of 60-year-olds who could not dress, bathe or feed themselves increased by 60 percent, as did those who could not shop, drive, use the telephone, do housework or prepare meals. Those with impaired mobility increased by 30 percent, and the number no longer able to stoop and climb stairs increased by 20 percent.

The risk of disability was much higher in minority-group populations and in those who had a long-standing history of obesity, a condition that increased in prevalence from 27.4 percent to 37.6 percent.

Beyond all the statistics and percentages, this study reveals an underlying problem in American society — we are getting less healthy with each passing generation. Baby boomers are not as healthy as their parents. They do not eat as well, are more sedentary and weigh a great deal more. Although this constellation of features does not necessarily shorten life expectancy, it definitely will affect quality of life.

The increasing prevalence of chronic illnesses, such as diabetes, heart attack and stroke, combined with severe back pain and arthritis limit aging Americans' ability to ambulate and remain independent. Without major changes to turn the tide against chronic disease, we will be a country overwhelmed with disabled older adults.

But this will not just affect the health care system. The ramifications will ripple out to virtually every corner of society from corporations to community groups, residential facilities to political action committees. Getting into a nursing home will be more competitive than getting into Harvard, and the financial burden on working Americans will be enormous.

We simply cannot afford to wait to change. Wake up America; wake up baby boomers, the writing is on the wall. Your health — and your children's health — is at stake. The disability epidemic can be avoided, but we are all responsible to act and contribute to positive change.

Dr. David Lipschitz is the author of the book "Breaking the Rules of Aging." To find out more about Dr. David Lipschitz and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate Web page at www.creators.com. More information is available at www.DrDavidHealth.com.