Older adults with the healthiest lifestyles could expect to spend about 1.7 fewer years disabled at the end of their lives, compared to their unhealthiest counterparts, the findings showed.

"The duration of the disabled period near the end of one's life has enormous personal and societal implications, ranging from quality of life to health care costs," said senior author Anne Newman, Professor at University of Pittsburgh Graduate School of Public Health in the US.

"We discovered that, fortunately, by improving lifestyle we can postpone both death and disability. In fact, it turns out that we're compressing that disabled end-of-life period," Newman noted.

The findings, published online in the Journal of the American Geriatrics Society, are based on analysis of a quarter century of data.

Newman and her colleagues examined data collected by the Cardiovascular Health Study, which followed 5,888 US adults for 25 years. 

All of the participants were aged 65 or older and were not institutionalised or wheelchair-dependent when they enrolled. 

The participants reported or were assessed for various lifestyle factors, including smoking habits, alcohol consumption, physical activity, diet, weight and their social support system.

The researchers took into account and adjusted results for such factors as participants' age, sex, race, education, income, marital status and chronic health conditions. 

Across all the participants, the average number of disabled years directly preceding death -- years when the person had difficulty eating, bathing, toileting, dressing, getting out of bed or a chair, or walking around the home -- averaged 4.5 years for women and 2.9 years for men.

For each gender, those with the healthiest lifestyle (those who were nonsmokers of a healthy weight and diet and getting regular exercise) not only lived longer, but had fewer disabled years at the end of their lives, the study said.