Dear Doctors: I always thought that your body ages gradually as you get older, kind of like your car does. But now I’ve been hearing that we actually go through a couple of spurts where we age really quickly. Can you please explain where this idea comes from?
Dear Reader: You’re referring to a study that made quite a splash when it was published last summer. Researchers at Stanford Medicine upended the idea that we age at a steady and measured pace throughout the course of our lives. Instead, the results of their research suggest that our bodies undergo two periods in which significant changes that take place at the molecular level add up to a sudden acceleration in aging. The first occurs at age 44 and the second at age 60. Not surprisingly, the idea that aging isn’t directly tied to chronology is still making headlines months later.
Working with scientists in Singapore, the researchers wanted to understand why the risk of certain diseases and health conditions appeared to spike at specific time points. In middle age, people often begin to get muscle injuries and see a marked increase in body fat percentage. In older age, they begin to lose muscle mass and develop an increased risk of cardiovascular and neurodegenerative disease, kidney disease and Type 2 diabetes.
To learn the reasons for these patterns, the research team recruited 108 adults ranging in age from 25 to 75 to take part in a multiyear study. The participants were asked to donate blood, stool, skin, nasal and other biological samples every few months. The researchers then analyzed age-related changes taking place in more than 135,000 different proteins, microbes in the gut, mRNA and other molecules. They found that at about age 44, and again around age 60, these molecules undergo rapid changes that correlate to the specific health risks associated with those ages.
For example, when you reach your mid-40s, a marked shift in your ability to metabolize alcohol occurs. That’s why the night out that barely fazed you in your 20s leaves you in rough shape in middle age. Other shifts include the ability to metabolize caffeine and changes to lipid metabolism and skin and muscle tone. In your 60s, caffeine metabolism takes another hit. So do the immune system and, again, muscle and skin. Interestingly, the data also suggest that some of the midlife changes that have been attributed to hormonal shifts in women during perimenopause are actually taking place at a molecular level and in both sexes.
So, how does this translate to daily life? At the most basic level, it underlines the importance of sticking to a healthful diet throughout your life. As you reach middle age, adjust your diet to anticipate fat gain and implement exercise routines to prevent muscle injuries. Caffeine drinkers should make appropriate changes. Ditto for alcohol use. Older adults can prepare for an accelerated rate of muscle loss, known as sarcopenia, by engaging in age-appropriate weight-training programs. The study also emphasizes the importance of regular health screenings, particularly at these pivotal times of life.
(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)
