The stress hormone, cortisol, at higher than average levels, can impair memory in adults, a new study suggests. Researchers tested 2,000 adults who had high cortisol levels and found they performed poorly compared to the average cortisol level group. In addition, they also showed less tissue volume in certain areas of the brain.
Cortisol is known as the body’s “fight-or-flight” hormone, as the adrenal glands secrete it in response to stress. But it also helps regulate metabolism, blood pressure, blood sugar, immune responses and inflammation.
Moreover, several animal studies showed that continuous high cortisol levels can also alter brain structure and function.
And in humans, there’s some evidence that certain medical conditions such as Cushing syndrome, in which there are high levels of cortisol, negatively affects brain structure and impairs memory.
Stress Hormone: Study Results
Data came from from 2,200 U.S. adults taking part in a long-term health study. They were divided into low, middle and high cortisol groups.
Participants with high cortisol levels scored lower on memory tests, attention, and thinking. On brain scans, they also show reduced volume in certain brain areas.
Some of the brain differences were seen in portions of so-called white matter, which is very important in information processing,
However, the researchers also pointed to the study’s limitations, including the one-time measurement of cortisol, which may not reflect chronic exposure to the hormone.
These results suggest further long-term studies with more frequent measurements of cortisol.