Stress: Your Brain and Body

23 Aug

The human body responds to stress with a powerful fight-or-flight reaction. Hormones surge through the body, causing the heart to pump faster and sending extra supplies of energy into the bloodstream.

This emergency response system is useful: It enables people to survive immediate physical threats, like an attack from a wild animal.

But today, the stress in most people’s lives comes from more psychological and seemingly endless pressures of modern life. Daily challenges like a long commute or a difficult boss can turn on the stress hormones — and because these conditions don’t go away, the hormones don’t shut off. Instead of helping you survive, this kind of stress response can actually make you sick.

Chronic stress can harm the body in several ways. The stress hormone cortisol has been linked to an increase in fat around organs, known as visceral fat. The accumulation of visceral fat is dangerous, since these fat cells actively secrete hormones that can disrupt the functioning of the liver, pancreas and brain, causing problems such as insulin resistance, inflammation and metabolic syndrome. Chronic exposure to other stress hormones can also weaken the immune system and even change the structure of chromosomes.

How Stress Affects the Brain

Recent research suggests that chronic stress takes a toll on the brain, too. Studies on mice show that stress-related hormones alter physical structures in the brain in ways that could affect memory, learning and mood. Some of these changes involve dendrites — tiny branch-like structures on nerve cells that send and receive signals. Several studies have shown that stress hormones can shrink dendrites and, as a result, information doesn’t get relayed across nerve cells. When the cell damage occurs in a part of the brain called the hippocampus, it can impact memory and learning.

If stress makes you feel anxious, damage to dendrites might be part of the cause. A 2011 study found that rats whose dendrites had eroded due to stress had higher levels of anxiety. Another study of adults with post-traumatic stress disorder suggests that the stress hormone cortisol may actually shrink the size of the hippocampus. Maybe this is because of the hormone’s toxic effect on neurons or there might be a genetic component — or both are involved.

Another part of the brain that seems to be affected by stress is the amygdala — the part of the brain that regulates fear and other emotions. A 2003 study found that in mice under stress, the amygdala grew larger while the dendrites in the hippocampus shrank.

As the amygdala grows in size, you may experience more anxiety and fear. (The amygdala is known to become bigger and more active in people who are depressed). But because the hippocampus cells involved in memory are shrinking and not transmitting information effectively, you can’t connect the feelings of fear to memories of real events. You’re left with a lot of generalized anxiety.

In any case you must: #1 Determine where your stress is coming from and #2 Find ways to reduce the effects of stress on yourself.

As much stress as there is today there are some profound physical, neurological, and metabolic answers to deal with the effects of stress.