This is a modified excerpt from Inside Your Head 🧠, a weekly newsletter exploring why your brain makes you think, feel, and act the way you do, written by me, Elemental’s senior writer and a former brain scientist. Subscribe here so you won’t miss the next one.
One of the few universally accepted truths right now is that 2020 is a stress tsunami of a year. And when your brain is too stressed for too long, seriously scary long-term consequences can occur, like depression and dementia. This news has probably contributed additional stress to some people, but stress isn’t all bad! In fact, research suggests that it can even be protective for the brain.
A study conducted by researchers in the Netherlands found that people who had mild to moderate stressful life events in old age, like the illness — but not death — of a loved one, had less cognitive decline than people who experienced either no stress or a very stressful event. Another study by epidemiologists at Johns Hopkins University found that people who were caretakers for a loved one lived 18% longer than people who didn’t have to take on that responsibility.
The theory is that these types of challenging, stressful situations in which you’re forced to adapt and change (like this pandemic) cause neurons to grow new pathways in the brain. Those new connections between brain cells, called synapses, are at the root of learning and memory, and they make the brain more resilient by offsetting the loss of other connections that typically occurs with old age.
The more synapses you have, the better protected you are against cognitive decline and dementia. In fact, research has shown that people with more of this so-called cognitive reserve don’t show memory loss or other symptoms of dementia, even if their brains have all the signs of Alzheimer’s disease.
The critical neurochemical in this process is noradrenaline, also called norepinephrine. Noradrenaline is the chemical that triggers the “fight or flight” stress response. In addition to all the physiological changes it causes (faster heart rate, sweaty palms, dilated pupils), noradrenaline also helps brain cells create new connections.
It turns out that noradrenaline is also the key to one of the simplest ways to regain control over a stressful situation: taking a few slow, deep breaths. Too much stress leads to too much noradrenaline, which can be overwhelming and lead to feelings of anxiety. Breathing helps control levels of noradrenaline in the brain. A slow, deep breath — try breathing in for five counts and out for six — reduces the amount of carbon dioxide in your brain, and that in turn lowers noradrenaline levels to back to their sweet spot.