Weight and your immune system
Though we’ve long known that being significantly overweight or obese at midlife could make us especially vulnerable to disease, nothing hammered that point home harder than the COVID-19 pandemic.
The reason: Around age 50, our immune system starts to show signs of aging, says Cornelia Weyand, M.D., an immune system researcher at the Mayo Clinic in Rochester, Minnesota. As you might expect, being significantly overweight increases one’s vulnerability.
Midlife is prime time for body dissatisfaction because we’re squeezed by society’s double whammy. You should be thin and you shouldn’t age.
This has played out over the pandemic years. Researchers looked at how weight affected outcomes for about 150,000 COVID patients. They learned that patients with a BMI of 30 to 34.9 (just above the “obesity” threshold) were 7 percent more likely to be hospitalized and 8 percent more likely to die than people who were a healthy weight. Those with a BMI of 45 or higher (considered “morbidly” obese) were 33 percent more likely to be hospitalized and 61 percent more likely to die. The connection was strongest among patients younger than 65.
“Obesity increases inflammatory signals. It’s like the fire alarm is always going off but there’s no emergency, so over time the immune cells become dulled to the stimulus,” says Jessica Lancaster, assistant professor of immunology at the Mayo Clinic in Phoenix. “Starting around age 50, there’s a decrease in the magnitude of the response to infection, as well as a delay. When there’s a deadly virus circulating and you have a sluggish immune response due to both weight and aging, you’re going to be at increased risk.”
The immune system can rebound if you bring your weight under control. Italian researchers reported in 2022 that when people with obesity — median age 51 — lost 10 percent of their weight, their immune systems responded more strongly to a COVID mRNA vaccine. A 2022 study at Brigham and Women’s Hospital of people with obesity who lost 18 percent of their body weight after undergoing a sleeve gastrectomy (a weight-loss surgical procedure that removes a large portion of the stomach) revealed that within three months, the patients’ immune systems were measurably healthier.
How we think about weight in our 50s
All this discussion of body fat and disease skirts a big issue: For many of us, weight is first and foremost a psychological concern. How we look in the mirror often generates strong feelings about self-worth and how the world perceives us. Those emotions can have physical repercussions.
If at midlife you’re unhappy with a body that’s suddenly heavier, wider and softer, you aren’t alone:
In a large University of North Carolina at Chapel Hill study, 89 percent of women in their 50s were dissatisfied with their bodies. And in a UCLA study of more than 52,000 U.S. adults, 46 percent of men 50 to 65 felt dissatisfied with their bodies for being “too heavy.”
About 52 percent of women and men in their 40s and 50s are trying to lose weight — more than in any other age group, according to the Centers for Disease Control and Prevention. Our perception of our own weight doesn’t always match reality: 26.5 percent of people dieting to lose weight are actually at a normal or low weight, this study found.
Midlife is prime time for body dissatisfaction because we’re squeezed by society’s “double whammy,” says psychiatrist Debra Safer, M.D., an associate professor of psychiatry and behavioral sciences at Stanford University who specializes in treating eating and weight disorders. “You should be thin and you shouldn’t age.”
“It’s a vicious cycle,” Safer says. “You might think weight stigma makes you thinner, but over time people make worse choices.” Body dissatisfaction is associated with higher risk for depression, binge eating (found in 19 to 26 percent of midlife and older women in a recent study), eating a less-healthy diet and engaging in less physical activity, and may be linked to less-than-optimal self-care for diabetes as well as avoidance of mammograms, skin exams and other cancer checks.
“It’s like the way you treat an old pair of sneakers versus a brand-new pair,” says body image researcher Lisa Kilpela, an assistant professor at the University of Texas Health Science Center at San Antonio. “When we don’t value our bodies, we don’t treat them very well.”
Bottom line: Your 50s may be the heaviest time of your life. But the number on the scale only tells part of the story. Now is the time to take positive steps that can have an enormous impact on your current and future health.