We live in a stressful time, that’s no secret. Consider the aftershocks of the pandemic, recent global tragedies and our polarized politics and add them to the usual challenges of work and family and it’s…a lot. It’s also no secret that too much stress is bad for your health. I’ve written about the health costs of excess stress and ways to bring it under control any number of times. When it comes to stress though, what is new is that integrative physicians like me appreciate that health is best understood as the ability to withstand the age-related decline in function in every part and system of the body, starting as early as our thirties. And stress? Cutting-edge research is now starting to pinpoint ways that stress turbocharges this natural aging process, making us old, and more vulnerable to “diseases of aging,” long before our time. So what are the ways that stress attacks body and mind? Here’s a topline on what you need to know to keep your body and mind on the low-stress path, how to fight stress as it pops up – and win:
What is stress anyway?
In strictly physiological terms, the stress response is all about the adrenal glands. At the brain’s command, one part of the adrenal glands pumps out cortisol, our primary energy hormone — a lot if we need to be very active, and just a little if we don’t, for instance, during sleep. Another part of the gland secretes “fight or flight” hormones like epinephrine (adrenaline) when we need an extra push to deal with a demanding or even threatening situation. A practical way to think about the stress response is to divide it into two: good stress and bad stress. Good stress means rising to the occasion, for instance, giving your all to a tough project at work, or even pushing up your heart-rate during a work-out or taking health-enhancing walk in the cold. (We call these little stress tests examples of “hormesis.”) Bad stress is when you can’t seem to stop over-revving. Instead of adapting to the environment, you’re being overwhelmed by it, wearing yourself out in the process. We’re all familiar with the physical effects: trouble sleeping, headache, GI distress, and the like. But what happens when high-stress becomes our new normal? Spoiler alert: we age faster.
A Belly Full of Trouble: The Metabolic Connection
Maybe the best understood way that stress ages the body is via our metabolism –how we burn or store energy. When the body produces a lot of cortisol over long stretches of time, that has the effect of increasing insulin resistance. And that leads to high levels of insulin (and, in the case of prediabetes and type 2 diabetes, high blood sugar), one of the great drivers of aging. Insulin resistance also results in more of the calories we consume getting stored as fat instead of being burned for energy, which inflames the entire system. At night, high cortisol interferes with sound sleep, tamping down the body’s production of the growth hormone responsible for maintaining our muscles and repairing cellular damage. Put all that together – and now picture the aging dial on your instrument panel being turned way up.
This Is Your Brain on Stress
Virtually no organ is more susceptible to losing altitude with age than the brain, with often tragic consequences. Stress is a bad actor that often plays an ensemble role in cognitive decline. High cortisol levels contribute to high blood sugar, in turn promoting the formation of plaque that gums up the brain’s small vessels, reducing or cutting off the supply of blood to the brain. The result: vascular dementia. But newer research has detailed some of the ways stress can directly injure the tissues of the brain. Studies have shown that it can kill neurons, shrinking brain volume, as well as increasing the amount of myelin (the neurons’ protective outer sheath) in certain parts of the brain, interfering with the way different parts of the brain communicate with each other. The hippocampus, involved in learning and memory, seems particularly vulnerable to stress. Studies in both animals and humans have made the connection between high cortisol and memory problems. It’s also implicated in depression (stress may play a bigger role here than brain chemicals like serotonin, despite the continued popularity of the serotonin-enhancing SSRI anti-depression drugs) and an elevated risk for neurodegenerative diseases like Alzheimer’s.
Going Deep: Stress and Aging at the Molecular Level
Researchers have followed the stress/aging trail all the way down to the tips our chromosomes, the telomeres, which allow our cells to continue to divide without falling apart. After many cell divisions in cells that divide all the time, like skin and gut cells, we begin to run out of telomeres. We don’t really know whether telomere shortening is a major cause of aging at the cellular level, or more of an effect. We do know that people with shorter telomeres die sooner, on average, than people with longer ones. And we know that people under great deal of stress, for instance women in caregiver roles, have shorter-than-average telomeres. If telomeres are a kind a cellular “clock,” stress is a reliable way of speeding it up. In one intriguing study, subjects that had received nine weeks of cognitive behavioral therapy to address their anxiety disorder had higher levels of enzymes that protect the telomeres. Possibly they’d slowed their cellular aging.
Other Stress-Aging Pathways, All Bad
In the past decade or so, scientists have come to a general agreement about which biological processes are driving the aging train. In virtually all of them, stress looks to be driving the train faster. With age, the mitochondria, the power plants inside our cells, run down. One review of some twenty animal studies found that stress, both acute and chronic, influenced how well the mitochondria did their jobs, suggesting another tantalizing link between what’s going on in our emotional lives and what’s going on in the microscopic structures of the cell. Other research is looking at how high cortisol pushes up oxidative stress, the waste products of metabolism, which, as we reach old age, begin to overwhelm our antioxidant enzyme defenses and contribute to our decline. More culprits: stress can help foul up the making and maintenance of essential proteins. It can interfere with cells’ ability to “take out the trash,” the necessary destruction of old, tired cells (autophagy), leaving behind “senescent” cells that spit out inflammatory molecules which all of us would be wise to avoid.
The Impact of Stress on Your Biological Age
“Biological age” captures the idea that the number of years you’ve been alive is less important than the wear and tear your cells have undergone during those years. A couple of years ago, researchers at Yale came up with their own way of measuring biological age, looking at changes in DNA, a so-called “epigenetic clock.” Sure enough, when they analyzed their subjects, all healthy, none over 50, they found that the amount of stress they had experienced in their lives impacted their bio-age. More stress, more years. But the good news was, the subjects who tested high on measures of psychological resiliency took a smaller stress hit, hard evidence that we can mitigate the health, and aging, effects of stressful life circumstances with a resilient frame of mind. Even better news? A study this past year that found that biological age was, at least in the short term, reversable, in other words, that we can age in both directions. They studied people whose bio-age had shot up after highly stressful events – major surgery, pregnancy, and severe COVID – and then, after a period of recovery, had come back down.
Fighting Back — And Aging as Slowly as Possible
For all the sophisticated science that has gone into the mapping these stress-aging pathways, the best antidotes to high stress/fast aging are smart lifestyle choices that I’ve been promoting for a long time. Think plants, protein, healthy fats and no-junk food to keep blood sugar and inflammation in check and metabolic aging under control. Physical activity, be it lots of everyday moving around or a more structured exercise program, is also wonderful for blood sugar control. Not only that, it chills you out and set you up for a restorative good night’s sleep. Add to that daily de-stressing, mind-calming activities – maybe it’s a meditation or a yoga practice or a walk in the park or a hot shower before bed, or all of the above. Anything that sooths the mind and gives you joy should put stress in its place – and keep aging on the slowest track possible.
