Stress. It is probably one of the biggest risks we face. The more worried you are that you might get sick, the more likely it is that you will, or if you do get sick that you'll end up sicker, or even dead, from an illness you might have survived if you just didn't worry so much. The more worried you are about the health of your heart, the more damage you do to your heart. The more worried you are about losing your memory, the more your memory fades. The list of damage that worry can do, because of the biology of stress, is long and scary. Which means that not worrying more than we have to may be the best thing we can do for our health.
We have Dr. Robert Adler to thank for bringing modern science and medicine around to what people have known intuitively for a long time; "If you don't relax you're going to worry yourself to death." Adler, who just passed away, and colleagues helped pioneer clinical research into the effects of stress on health, which are brilliantly summarized in Robert Sapolsky's fabulously entertaining and informative book Why Zebras Don't Get Ulcers. Zebras don't get ulcers because when they are under attack, they either run away, or get eaten. They don't stay stressed. We get ulcers, and suffer a lot of other serious damage, because we do.
It may not seem the same...being chased by a hungry lion and worrying about how the economy is going or about that new strain of flu going around...but it is. Worry...feeling threatened to any degree...is stress. It sets off a Fight or Flight survival response, which triggers all sorts of changes in our bodies. The systems more important for immediate survival, like blood pressure and heart rate to circulate more energy throughout the body, get turned up, and the ones not so important for immediate survival, like our immune system or digestion or fertility, get turned down. Those changes help us run away from, or fight off, the lion. But if the figurative danger keeps us in that Fight or Flight mode for more than a couple weeks, we're in for all sorts of trouble.
• Persistently elevated blood pressure and heart rate raises your risk of cardiovascular disease, which is already the leading cause of death in the developed world.
• A depressed immune system makes it harder for your body to fight off all sorts of diseases, including cancer, or battle them once you do get sick.
• Stress reduces the protective fluids in the lining of the digestive system exacerbating the risk and severity of ulcers and other digestive disorders.
• Stress changes blood chemistry, and if persistent, those changes raise your risk of diabetes.
• Those chemistry changes are also why chronic stress is associated with greater likelihood of clinical depression.
• Chronic stress impairs the formation of new fast-growing cells, like bone, and hair. Worry a lot, for a long time, and you can go bald.
• Chronic stress reduces your ability to form some new memories, and recall others. At high levels, stress literally dumbs you down.
• You don't need to worry about making babies when the lion is attacking, so stress depresses fertility.
To do this damage the worry/stress has to persist for at least a couple weeks. And it has to be out of the ordinary stress, not the daily hassles of ‘my commute sucks' or ‘my boss is a jerk', the kind of stress we get used to. That's what neuroendocrinologist Dr. Bruce McEwen calls ‘allostasis' (in his wonderful book The End of Stress As We Know It) which basically means our body can adjust to being under stress, and all those systems that get turned up or down when we really feel threatened come back into balance.
But the stress need not be severe. Our worries can be dangerous even if they're not existential. Any worry at all, even the little nagging stuff we're not even aware of, can cause a mini Fight or Flight response. It's easy to be aware of the threat of terrorism or climate change or that jerk driving next to you and sending a test message from his phone, the bogeymen that stare you right in the face. But we also have to recognize the danger of nagging low-grade stress. There is a huge hidden cost to your health, and indeed your longevity, from worrying too much.
This is one of the dangers of what I call "The Perception Gap" (in How Risky Is it, Really? Why Our Fears Don't Always Match the Facts), when our innately subjective/instinctive/emotional system of risk perception leads us to worry about some threats more than the evidence suggests we need to. As much as we need to heed what Dr. Adler and others have taught us about the biological dangers of stress, we also need to apply the wisdom that Paul Slovic and Dan Kahneman and many others have gained about the psychology of risk perception. Their research has revealed why our fears don't always match the facts. Understanding why The Perception Gap occurs, and why some risks feel scarier than the facts and probabilities indicate, is a self-awareness we can use to minimize the dangers of disproportionate worrying.
We could just pop some valium and ativan and xanax or other drugs to combat stress. Or we can also try to apply our understanding of what makes some risks feel scarier than others to try to keep our fears in perspective. That sort of self-control, overriding our instincts, will be hard. But it will be easier if we first recognize, and feel actually threatened by, the hidden but huge risk of stress that comes from worrying more than we need to.