Michelle Obama has done an excellent job mobilizing the nation to combat childhood obesity and encouraging kids to eat better and move more. But now her efforts may be needed on another front.
Obesity can take a heavy toll on older women, too: Their risk of developing chronic diseases, losing the ability to walk or dying earlier increases with excess weight. We get the particulars from a large national study, recently published in JAMA Internal Medicine, that tracked more than 36,000 post-menopausal women at 40 research centers and universities around the US.
When the women enrolled in the Women’s Health Initiative between 1993 and 1998, they were between 66 and 79 years old (average age: 72). When the study concluded in 2012, the researchers found that the women fell into five categories:
* 19 per cent of these women were deemed healthy, meaning that “they survived to age 85 and had no major chronic diseases and maintained the ability to walk,” said lead author Dr Eileen Rillamas-Sun, an epidemiologist at the Fred Hutchinson Cancer
Research Center in Seattle.
* Another 14.7 per cent began the study with one or more of five chronic disease (cancer, heart disease, stroke, diabetes or hip fracture), but did not develop any additional health problems, and remained mobile.
* Nearly a quarter, 23.2 per cent, developed one or more of the diseases during the study period, but maintained their ability to walk.
* 18.3 per cent did lose their mobility — meaning they required crutches, walkers or wheelchairs — or reported limited ability to walk a block or climb a flight of stairs. The researchers used this measure of disability, Dr Rillamas-Sun said, because “losing one’s ability to walk contributes to loss of independence.”
* The remaining women, 24.8 per cent, died before age 85.
When the researchers looked at the impact that obesity or being overweight — calculated by body mass index — took on the women’s health, “we found that women with a healthy body weight had a greater chance of living to 85 without developing a chronic disease or a mobility disability,” Dr Rillamas-Sun said. “The heavier you are, the worse your chances of healthy survival.”
Now some readers are already mentally composing comments like, “Didn’t we already know that obesity is bad for us?” and “We needed a study funded by the National Institutes of Health to tell us this?”
We did, on both counts. But older people and women have historically been under-represented in — or actually excluded from — research trials. For years, experts assumed that findings from all-male studies applied to women, too, which has proved to be untrue.
Also, aside from gender disparities, “a lot of research focuses on everyone 65 and older,” Dr Rillamas-Sun pointed out. “We looked at the old-old” — those who are 85-plus.
But it is true that this work confirms what we thought we knew: Overweight women run a higher risk of health problems and disability, and those risks rise sharply when overweight becomes obese.
Compared to older women with healthy body mass indexes (below 25), overweight women had a 20 per cent greater chance of developing one of the five diseases. But women with Level 1 obesity (BMI over 30 but below 35) had a 65 per cent higher risk of disease, and women with higher levels of obesity were more than twice as likely to develop disease. The likelihood of dying before age 85 showed a similar pattern. (The data has been adjusted to account for demographic differences and health behaviours like smoking.)
When it came to losing mobility, the researchers found even more striking differences. Overweight women had a 60 per cent higher risk of losing the ability to walk, but obese women were three to six times more likely to lose their mobility. For African-American and Hispanic women who were overweight or obese, the odds of disease, disability or death before age 85 were higher yet.
What this study doesn’t address is whether losing weight later in life can protect older women from disease and disability. But the researchers are working on that. (And of course, some factor other than obesity might be involved because — all together now — correlation is not causation.)
But we shouldn’t wait for Dr Rillamas-Sun’s next publication to try to reduce obesity in older women.
Paging the First Lady. Women often do gain weight after menopause, and losing it can be harder than when we’re 35 (a challenge with which I’m all too familiar).
But it’s not impossible, and the effort is worth undertaking — for our aging parents, and for ourselves.
“This says, you can’t be in denial any longer,” said Dr Rillamas-Sun. “Most people need to see the numbers; they prove what is supposedly obvious. And we do have the numbers.”