Why your mother’s age could be the key to longevity

SAN DIEGO — Women whose mothers lived to 90 years have a 25 per cent greater chance to also live that long, compared with those whose mothers didn’t, according to a new study led by University of California, San Diego (UCSD) researchers.

Moreover, the women achieved this extreme longevity while staying healthy. They had no major chronic diseases, such as heart disease, diabetes, cancer, hip fracture or physical limitations.

When both parents survived to 90 years, the advantage jumped to 38 per cent, said the study, published in the journal Age and Ageing.

If only the father lived to be 90, there was no increase in healthy longevity for the daughter.

These results are probably a combination of genetics, environment and behaviour, said UCSD’s Aladdin Shadyab, who led the study. It examined the health records of a racially and ethnically diverse population of more than 20,000 women.

The study used information from the Women’s Health Initiative, a large, long-term study on major risk factors for chronic diseases. It enrolled more than 160,000 post-menopausal American women when it was launched in 1993.

Since only women are tracked in the initiative, the study did not examine men or parental life span effects on sons.

The initiative has yielded a wealth of information about women’s health, including the effects of hormone therapy, diet and supplementation with calcium and vitamin D.

Previous research jibes with the study’s findings, including health in the greatly long-lived, the study said.

“In the New England Centenarian Study, offspring of centenarians had 78 per cent, 83 per cent and 86 per cent lower risk of developing myocardial infarction, stroke and diabetes, respectively, than a similarly aged referent cohort,” the study said.

A lot of factors go into total life expectancy. This effect of long-lived parents adds an additional calculation.

For a baseline comparison, 34 per cent of all American women 65 years old will live to 90, according to the Social Security Administration. The increase in life expectancy is calculated compared to this base. (Just 22 per cent of men of that age will reach 90).

In addition, total life expectancy has grown over the decades. In 1965, just 25 per cent of 65-year-old American women lived to 90, and only 10 per cent of the men.

In addition to outside factors such as exercise and diet, researchers in recent years have found some genetic traits that appear more commonly in those who achieve very long lifespans.

“There are specific genes that predict your ability to live longer, which these women likely inherited from their parents,” Shadyab said. Researchers don’t know, however, why the mother’s longevity seems to play a more important role in a daughter’s lifespan than the father’s.

“Further, the women whose parents lived longer had higher socieconomic status, meaning that they were more educated with higher income,” he said. “And growing up in a high socioeconomic environment predicts your chances of living longer and aging well.”

Those in high-income households tend to have access to better health care and education on healthy habits, and presumably those influences play a role.

It’s possible that the parents who lived to 90 also practiced good health habits that they passed along to their daughters.

“More studies are needed to determine how genetic factors interact with behavioural factors like physical activity and socioeconomic status to influence our future aging outcomes,” Shadyab said.

Other studies have looked at health in aging. In San Diego, the ongoing “Wellderly” study tracks men and women who have reached their 80s and beyond, to look for genetic and lifestyle factors that may influence their longevity.

If women want to know how the results apply to them, their present age makes a difference.

Older people have a better chance of great longevity than younger people. That’s because some younger people will die prematurely, whether by illness or injury, and never reach old age. By definition, the elderly have already survived these dangers.

For young women, this means that environmental and behavioural patterns are much more important to attaining extreme longevity than for those who are already older.