"Apparently, high levels of & # 39; cortisol, hormones & # 39; stress, predict the function of the brain, the brain size and performance on cognitive tests," said Sudha Seshadri, author & # 39, study and professor & # 39; Neurology in the University Science Center. Health & # 39; University & # 39; Texas in & # 39; San Antonio.
"We discovered that memory loss and incorporation of the brain can be detected in & # 39; relatively very few, long before people can be found symptoms", said Seshadri.
Too & # 39; fight or flight & # 39;
Cortisol is one of the major stress hormones, most known for its intervention in the instinct of fight or flight. When we are stressed or warning, the adrenal glands produce more cortisol. The hormone then causes the suspension of & # 39; various body functions that could interfere with survival.
Once the crisis is over, levels & # 39; cortisol to go down and body systems to return to normal. But if the button & # 39; Your alarm is pressed, the body can & # 39; remains & # 39; malfunction, causing anxiety, depression, heart disease, pain & # 39; headaches, weight gain, trouble sleeping and, of course, problems & # 39; memory and concentration.
According to experts, the brain is particularly vulnerable because of the amount of & # 39; nutrients it needs to function properly.
"The brain is a hungry organ", said Keith Fargo, director of scientific programs and linking Alzheimer's Association. "It requires a huge amount of & # 39; nutrients and oxygen to stay & # 39; working properly, so when the body needs those resources to deal with the stress, there is less to send to the brain."
The intense stress is related memory loss
In previous studies, found a relationship between cortisol and the risk of developing dementia; However, the study focused on the elderly and the area of the brain which is memory, called the hippocampus.
Among the advantages of the new study, according to Seshadri, is a group & # 39; men and women & # 39; 48 years on average and were analyzed MRIs were in the mind, not just ispekampus.
The researchers chose more than a thousand people who showed no signs of dementia and applied several psychological tests to assess their cognitive abilities.
They were all part of the Heart Study & # 39; Framingham, long-term study sponsored by the National Institute of Heart, Lungs and Blood & # 39; USA. The study analyzed the health of residents & # 39; Framingham, Massachusetts – and their children – by 1948.
The group again & # 39; was assessed about eight years after initial tests. The cortisol blood was measured before breakfast. Then become magnetic resonances and memory and cognition tests were repeated.
Having adjusted the data by age, sex, the body mass index and smoking, it was established that people who had the highest levels of & # 39; cortisol had the highest loss & # 39; memory.
"I was not surprised by the change in cognition," said Fargo, who was not involved in the study. "If you have higher cortisol, you are probably stressed and x & # 39; likely to have more difficulties in cognitive tests."
Stress also affects brain structure
Fargo noted that what was striking findings on the effects of cortisol on brain structure.
High levels of & # 39; cortisol were associated with & # 39; greater damage to parts of the brain to move data through the body (radiant crown) and between the hemispheres (corpus callosum).
In addition, the study showed that the part of the brain responsible for the functions of thought, emotions, speech and muscle was smaller in & # 39; people who had higher levels of & # 39; cortisol.
The average brain volume & # 39; people who had high levels of & # 39; cortisol was & # 39; 88.5% of the total volume of the brain, b & # 39; difference of 88.7% of people with & # 39; & # 39 normal levels; Cortisol.
"I'm surprised that we could see a major change in brain structure with & # 39; elevated & # 39; cortisol compared to & # 39; & # 39 moderate levels, cortisol," said Fargo. "If you notice structural changes in the brain & # 39; middle age, you & # 39; & # 39 x imagine; it will happen by the time you old enough to develop dementia."
Interestingly, apparently, the effects of & # 39; elevated cortisol on the volume of the brain occurs only in women, not in men.
"The estrogen can & # 39; triggers cortisol," said Richard Isaacson, medical director of the Prevention Clinic & # 39; Alzheimer School of Medicine at Weill Cornell University in the United States. "About 40% of women in the group & # 39; high cortisol in the study were on therapy & # 39; hormonal replacement." Isaacson did not participate in the study.
Seshadri said that adjustments in therapy study took into account & # 39; hormone replacement. "This does not completely adverse effect of the substitution rule of & # 39; hormones," he added, "but it is less likely in & # 39; this story."
Seshadri also stressed that the results of the study show only a relationship, not a cause, and the need for & # 39; further research to determine the relationship between elevated levels of & # 39; cortisol and dementia. He proposes that while this happens, people should think to make changes in the style of & # 39; their lives to combat the stress of modernity.
Fargo agrees. "We know, for example, that people who exercise have a lower lifetime risk of developing dementia," he said. "Take time for yourself, doing meditation, there are always ways to control stress that gives positive results."
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