Two US studies have suggested that it’s never too late to make a difference to one’s odds of living longer. One study showed that having a healthy lifestyle in early elderly years was linked to greater odds of living to 90 in men, and a second study showed that although some people live to be over 100 by avoiding certain diseases, others do live with them to this age without becoming disabled.

Both studies are published in the 11th February issue of Archives of Internal Medicine.

While research on twins has shown that genes play a part in how long we are likely to live, nearly three quarters of the odds of living to a ripe old age of 90 or more, is down to “modifiable factors”, or things we can change, wrote researchers in one of the articles.

In the first study, Dr Laurel B Yates of Brigham & Women’s Hospital, Boston, and colleagues examined records on 2,357 men of average age 72 when they became participants in the Physician’s Health Study between 1981 and 1984.

The records included a range of demographic and health data such as height, blood pressure, weight, how often they took exercise, and cholesterol levels. The men also completed questionnaires twice in the first year and then once every following year until 2006. This asked them about their health, habits and ability to carry out every day tasks.

The results showed that:

  • 970 men lived to be 90 or more (41 per cent).
  • Several “modifiable” factors about their biology and behaviour were linked with survival for this group.
  • Smoking, diabetes, obesity, and high blood pressure appeared significantly to reduce the odds of living to 90 or more.
  • On the other hand, vigorous exercise, “substantially improved it”.
  • Also, men who lived to 90 and beyond had better physical function, mental wellbeing and rated themselves as healthier in late life than the men who died younger.
  • Smoking, obesity and having a sedentary lifestyle were also significantly linked to poorer functional status in elderly years.

Yates and colleagues estimated that a 70 year old man who did not smoke, was of normal weight, had no diabetes, exercised two to four times a week, and had normal blood pressure had a 54 per cent chance of living to be 90 years old.

But, if he had any “adverse” risk factors, his chances of living to 90 were reduced, depending on what they were. Thus each factor would reduce the 54 per cent to the following amount:

  • Sedentary lifestyle reduced the chances of living to 90 from 54 to 44 per cent.
  • High blood pressure reduced it to 36 per cent.
  • Obesity, 26 per cent.
  • Smoking, 22 per cent.
  • Three factors together, such as sedentary lifestyle, obesity and diabetes, 14 per cent.
  • Five factors, 4 per cent.

The authors concluded that:

“Although the impact of certain midlife mortality [death] risks in elderly years is controversial, our study suggests that many remain important, at least among men.”

They therefore recommended that:

“Healthy lifestyle and risk management should be continued in elderly years to reduce mortality and disability.”

For the second study, Dr Dellara F. Terry of the Boston University School of Medicine and Boston Medical Center, and colleagues, examined data on 523 women and 216 men age 97 or older. The data came from questions the participants had answered in a telephone interview or mailed questionnaire about their health and medical history and their ability to function.

Dellara and colleagues put them into groups according to gender and the age at which they developed diseases normally linked to aging, such as COPD (chronic obstructive pulmonary disease), dementia, hypertension, osteoporosis, Parkinson’s disease, stroke, diabetes and heart disease. Those who developed these diseases at the age of 85 or more were called “delayers”, and those who developed the diseases before they reached the age of 85 were called “survivors”.

The results showed that:

  • 32 per cent of the participants were survivors and 68 per cent were delayers.
  • Centenarians who had developed heart disease and/or high blood pressure before they got to 85 showed similar levels of function as those who delayed illness until 85 or later.
  • Levels of function were described as “independent” in men and “requires minimal assistance” in women.
  • Though fewer men than women live to a an extremely old age, the men in this study who did so appeared to have better mental and physical function than the women.

Speculating on their results, the authors suggested that “men must be in excellent health and/or functionally independent to achieve such extreme old age.” But women, they said, “may be better physically and socially adept at living with chronic and often disabling health conditions”.

The researchers concluded that the timing of illness in centenarians may explain the “various ways in which people can survive to extreme old age”.

“Determining the mechanisms that facilitate the delay or escape of disability in the face of clinically evident age- and mortality-associated morbidities merits further investigation,” they added.

In an accompanying editorial, Dr William J. Hall, of the University of Rochester School of Medicine & Dentistry, New York, wrote that the 85s and over is the fastest growing group of older Americans. They will need regular medical care, he added:

“The challenge to current health care providers is to become adept at caring for present and future centenarians with only the beginnings of concrete evidence-based research.”

“Our ability to adapt to this challenge may be a prime determinant in shaping the nature of primary care practice in this country,” wrote Hall.

“Exceptional Longevity in Men: Modifiable Factors Associated With Survival and Function to Age 90 Years.”
Laurel B. Yates, Luc Djoussé, Tobias Kurth, Julie E. Buring, and J. Michael Gaziano.
Arch Intern Med. 2008;168(3):284-290.
Vol. 168 No. 3, February 11, 2008

Click here for Abstract.

“Disentangling the Roles of Disability and Morbidity in Survival to Exceptional Old Age.”
Dellara F. Terry, Paola Sebastiani, Stacy L. Andersen, and Thomas T. Perls.
Arch Intern Med. 2008;168(3):277-283.
Vol. 168 No. 3, February 11, 2008

Click here for Abstract.

Written by: Catharine Paddock, PhD