When one is continually stressed by life experiences, the brain shrinks.

The brain is an important organ in the body responsible for the coordination of several activities. However, too much stress could lead to the shrinking of this vital organ, reports Saliu Gbadamosi.

THE human brain is a very vital organ that controls virtually every part of the body. It is a complex and sophisticated organ without which the person is dead. In fact, it is the coordinator of every part of the human body. As vital as this organ is to a person’s existence, man’s day-to-day action or inaction can age the brain even before the person comes of age.

Researches have shown that stress can have adverse effects on the human brain. Professor Robert Sapolsky of the Department of Biological Sciences of Stanford University, Stanford, USA, in a recent article in the journal Science reports that there are links between long-term stressful life experiences, long-term exposure to hormones produced during stress, and shrinking of the part of the brain involved in some types of memory and learning.

They were able to show that some stress hormones, called glucocorticoids, spell bad news when brain cells are exposed to them for a long time. The team of researchers at the University of Pennsylvania School of Medicine found from a stress test they conducted using functional Magnetic Resonance Imaging (fMRI) that there is an increase in blood flow to the right prefrontal cortex of the brain when a person is under stress. The prefrontal cortex is an area associated with anxiety and depression.

The study showed that the neurons of hippocampus region of the brain which is responsible for explicit, declarative memory ­ for knowing a fact like your name, those of your family members, among others, are rich in glucocorticoid receptors. This is the region where animal studies have shown that stress hormones can damage its neurons.

One may ask at this juncture what then is stress? MedSearch defines stress as: “The sum of the biological reactions to any adverse stimulus, physical, mental or emotional, internal or external, that tends to disturb a person’s normal state of well-being.”

This implies that stress is actually the effect that human beings experience in their bodies due to adverse stimuli. To a lay man, stress is a physical or mental tension or strain on his body. Speaking on the effect of stress on the brain, Dr. L. F. Owolabi of the Neurology Department of the University College Hospital (UCH), Ibadan, said stress is complex and has a relationship with the brain, submitting that if an individual is stressed, one of the first organs to respond to it is the brain.

“The brain is an important organ in the body. There are over 10 billion neurons that constitute the human brain,” he said, explaining that prolonged exposure to stress can kill these neurons. “When a person is under stress, his brain produces hormones which stimulate other organs to produce stress hormones called cortisol. The cortisol is produced by the adrenaline glands and they are agents in the body to counteract stress.”

Also speaking on the subject, Dr Folorunso Adegoke of Immaculate Specialist Hospital, Oke Ado, Ibadan, said the human brain is fully developed at age two, adding that after the age of 40, the brain starts to age as the law of diminishing returns gradually sets in.

Dr. Adegoke stated that there is a limit to how the brain could be stressed, submitting that the more an individual stresses himself, the more he ages his brain, which in turn makes the person look physically aged.

“There is a limitation to how the brain can be stressed. If you stress yourself beyond the limit, the effect is that your brain ages faster than your actual age,” Dr. Adegoke submitted. He said that a long-time stressful experience leads to the shrinking of the brain. In the long run, he stated that this could lead to Alzheimer’s disease.

“When an individual is continually stressed by life experiences, the brain of the person tends to shrivel, that is, it shrinks. This could lead to a mental problem called Alzheimer’s disease which is a primary degenerative disorder. This is why we always advise people to try as much as possible to avoid stressful situations which will eventually affect them.”

Since we cannot do without experiencing stress in one way or the other, what then must be done to avoid subjecting the brain to untimely ageing? Dr Adegoke advised that every one should rest his brain sufficiently. “We have to allow our brain to rest adequately by having good sleep. When you sleep, the brain is at rest as it is not functioning at this time,” he stated.