How Stress Can Shrink Your Brain and 6 Ways to Keep It from Happening

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Prolonged exposure to stress can take a toll on your body and brain. Help maintain brain size and function as you age with these tips.
“Whatever doesn’t kill you makes you stronger,” goes the phrase. And somehow, we all actually believe it.
We humblebrag that we’re stressed about work, our families, our finances, and how hard and time-consuming it is to plow through everything on our vast and daily to-do lists.
We’re super stressed about politics, natural disasters, climate change — even who will win the Super Bowl.
Stress may be an unavoidable part of life, but when you get stressed and stay stressed, it’s no badge of honor.
Think of the last prolonged stressful situation you were in. Not something that lasted an hour or two, like a root canal at the dentist’s office, but one that lasted weeks, months, or even years: a high-intensity job with a ruthless boss, for instance, or caring for a sick parent.

During that time, did you eventually find it harder to make simple decisions, remember the right word for something, or just keep track of your car keys?
At the time, it might have felt like the universe was conspiring against you. But there’s a scientific reason for what was more likely happening: Stress has the ability to physically shrink your brain.
More stress equals less gray matter
When you get stressed, your body releases cortisol, aka the stress hormone.
In limited bursts, this isn’t a bad thing. Cortisol has the power to lower your blood pressure, manage your blood sugar, and reduce inflammation within the body.Researchers at the University of California at Berkeley even found that when lab rats were exposed to brief stressful events (“brief” being the operative word), stem cells in their brains actually bloomed into new nerve cells. As a result, the rats’ mental performance improved.
But chronic stress — that is, repeated and prolonged exposure to something stressful, like the demanding job or gravely ill parent mentioned above — doesn’t offer the same perks.
Over long periods of time, elevated levels of cortisol can push you further down the road toward obesity, heart disease, depression, high blood pressure, and unhealthy lifestyle behaviors.
There’s proof it takes a toll on your gray matter as well.
“High cortisol levels secreted due to stress damage and reduce the volume of the brain,” said Dr. Janette Nesheiwat, a board-certified family and emergency medicine doctor in New York City. “We can see this on scans of the brain.”
Two areas affected are the hippocampus, which plays a central role in learning and memory, and the prefrontal cortex, which regulates thoughts, emotions, and actions by “talking” to other brain regions.
In a recent study published online in the journal Neurology, researchers checked cortisol levels in the blood of 2,231 healthy middle-aged people. They also assessed their memory and thinking skills and took images of their brains.
What they found was that participants — particularly women — who had high levels of cortisol in their blood did poorer on memory and cognitive tests. Over time, they also appeared to lose brain volume.
“Slightly lower brain volumes and memory performance of the magnitude seen in this study are associated with a higher risk of dementia 10 to 20 years later,” said Dr. Sudha Seshadri, one of the study’s authors and director of the Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases at UT Health San Antonio.
Dr. Monica Starkman, a faculty psychiatrist at the University of Michigan Medical School, observed a similar “shrinkage” phenomenon in patients with active Cushing disease. It’s a rare condition in which too much cortisol is produced in the body.“When we used [an] MRI to examine their brains, we found that indeed, the hippocampus was reduced in size compared to norms for human subjects,” Starkman said.
“The hippocampus is important for learning, and we found that scores for learning were associated with the volume of the hippocampus.”