Recent research published in Neurology , the medical journal of the American Academy of Neurology, reveals that the brain volume of individuals with higher blood levels of cortisol , the substance produced by the adrenal gland known as the stress hormone , is smaller.
And what consequences does this have? A priori, it makes them more difficult to memorize and remember , although Dr. Sudha Seshadri, professor of neurology at the Center for Health Sciences at the University of Texas at San Antonio and author of the study, clarifies that this cannot be deduce, at least for the moment, that having more stress necessarily implies that the size and functionality of our brain is reduced: “Higher levels of cortisol seem to predict brain function, size and performance in cognitive tests, but for now we can only say that there is a connection but not that there is a causal relationship between the two events . “
This is not the first time that scientists have linked anxiety and stress to brain changes, but so far most studies have focused on older people. However, this research aims to evaluate the association of morning cortisol with cognitive performance and brain structure in young and middle-aged adults who do not have signs of dementia or other manifestations of age-related cognitive impairment.
“We have seen in research that there was memory loss and brain shrinkage in middle-aged people before symptoms began to show, so it is important to look for ways to reduce stress, such as getting enough hours of sleep, moderate exercise, incorporate relaxation techniques into daily life or check cortisol levels in the doctor and take a reducing medication if necessary, “recommends another of the study authors, Justin B. Echouffo-Tcheugui, from the School of Medicine from Harvard in Boston, Massachusetts.
Cortisol is a hormone that helps the body control anxiety , reduce inflammatory processes, improve the functioning of the immune system, metabolize proteins, fats and carbohydrates, and keep blood sugar levels and blood pressure constant. Cortisol levels in the bloodstream vary throughout the day because they are related to the activity we develop. They tend to be highest in the morning –between 5 and 23 mcg / dL– and decrease throughout the day, reaching between 3 and 16 mcg / dL.
According to Echouffo-Tcheugui, “Cortisol affects many different functions, so it is important to thoroughly investigate how elevated levels of this hormone can affect the brain.”
The study method
To carry out their study, researchers led by Seshadri and Echouffo-Tcheugui studied the brains of 2,231 apparently healthy people with a mean age of 48 years. They drew this sample of individuals from the Framingham Heart Study, a comprehensive study of the health of a Massachusetts community since 1948 that has spanned three generations .
The participants underwent various psychological tests to assess their memory and reasoning skills, as well as blood tests and brain scans. Eight years later, they had to pass some similar tests and were divided into three groups based on their low, medium, or high blood cortisol levels.
After considering other parameters such as age, gender, body mass index, or whether or not they were smokers, the authors found that people with the highest cortisol levels tended to remember worse and have trouble maintaining attention , and their brains also had smaller volumes, especially women.
Beware of hasty conclusions
However, McEwen and Seshadri warn against jumping to the conclusion that stress is to blame for everything , as the study results only show an association, not a cause, and that more research is needed to determine if it really There is such a causal relationship between high cortisol levels and dementia. If anything, they recommend that, in the meantime, people consider making lifestyle changes to combat stress.
