Former elite football players may age faster than their more average peers, a new study suggests.

NFL players, especially former linemen, had fewer disease-free years and earlier high blood pressure and diabetes diagnoses. Two age-related diseases, arthritis and dementia, were also more commonly found in former football players than in other men of the same age.

This research was part of the ongoing Football Players Health Study at Harvard University.

"We wanted to know: Are professional football players being robbed of their middle age? Our findings suggest that football prematurely weathers them and puts them on an alternate aging trajectory, increasing the prevalence of a variety of diseases of old age," said senior investigator Rachel Grashow, director of epidemiological research initiatives for the Football Players Health Study.

"We need to look not just at the length of life but the quality of life," she said in a university news release. "Professional football players might live as long as men in the general population, but those years could be filled with disability and infirmity."

For this research, nearly 3,000 former NFL players completed a survey for investigators at the Harvard T. H. Chan School of Public Health and Harvard Medical School.

"Our analysis raises important biological and physiological questions about underlying causes but, just as importantly, the results should serve as an alarm bell telling clinicians who care for these individuals to pay close attention even to their relatively younger former athlete patients," Grashow said. "Such heightened vigilance can lead to earlier diagnoses and timelier intervention to prevent or dramatically slow the pace of age-related illness."

Researchers were intrigued by conflicting reports in which athletes reported feeling older than their chronological age, while past research showed they lived as long as or longer than men in the general population. Sports medicine physicians who treat players had also reported that these athletes often experience an earlier onset of age-related chronic health conditions.

Participants in the study were 2,864 Black and white former pro football players, ages 25 to 59.

Researchers also used survey data to measure how long the athletes lived without developing four health conditions (dementia/Alzheimer's disease, arthritis, hypertension or diabetes), comparing the results to other non-NFL men ages 25 to 59 who had been part of the National Health and Nutrition Examination Survey and the National Health Interview Survey.

In each decade of life, the former athletes were more likely to report that they'd been diagnosed with dementia/Alzheimer's disease and arthritis, the study found.

Younger players, ages 25 to 29, were more likely than the average population to report high blood pressure and diabetes.

The effects persisted even after the researchers accounted for body mass index and race.

The research team also analyzed player health for different game-related aspects, such as what position the athletes played. They found that linemen, who are known to have more physical contact during games, had shorter health spans and developed age-related disease sooner than those who were not linemen.

Later diagnosis and treatment for metabolic conditions such as hypertension and diabetes could have long-term effects on heart health and cognition, study senior author Dr. Aaron Baggish said in the release. He is director of in-person assessment studies at the Football Players Health Study.

"The duration of one's life is very important, but so, too, is the quality of one's life," added Baggish, a professor of medicine at the University of Lausanne in Switzerland. "This study was conducted to probe the latter and now provides an important perspective on how early-life participation in the great game of football may accelerate the onset of certain common forms of chronic disease."

Future studies will focus on the biological mechanisms that are causing this premature aging among football players and interventions to help them live healthier lives, Grashow said.

The findings were published Dec. 8 in the British Journal of Sports Medicine.