"Better to hunt in fields, for health unbought,
Than fee the doctor for a nauseous draught,
The wise, for cure, on exercise depend;
God never made his work for man to mend."
On these pages, I have tried to show how the mind influences the body. Thus, maintenance of the mind is important to the well-being of the body. Experimental rats exposed to stress and increased stress hormone corticotrophins have decreased brain-derived neurotrophic factor (BDNF) and may lead to atrophy of the hippocampus. People with chronic depression have also shown these features.
Studies show BDNF increases in the brain with treatment of depression, exercise and participation in intellectual activities. It now appears that vigorous physical activity in the form of exercise can even be better than drugs in helping the brain maintain its function. A recent study showed that aerobic workout for 3 months in humans was enough to coax an area of the brain called hippocampus, just under the brain, to form new cells. Until now, scientists working in this field thought this phenomenon was impossible. The hippocampus is involved with learning and memory. Thus, the growth of new cells rewires the hippocampus to rejuvenate and maintain memory to reverse the effects of aging on the brain.
During exercise, the muscles send chemicals (IgF-1) that travel to the brain to help produce brain-derived neurotrophic factor (BDNF) that causes growth of new cells. Though new cells cannot grow throughout the brain, studies have found that in aging brains some parts of the brain cells rewire themselves with exercises.
Brain scanning studies by Arthur Kramer, a psychologist, showed that the frontal lobe, where decision making and planning take place, increases in size with exercise such as brisk walking. The subjects also improve on psychological tests. Anatomically, what happens is increase in the growth of new blood vessels and increase in the chemicals involved in transmitting information from cell to cell called neurotransmitters such as dopamine, serotonin and nor-epinephrine. These chemicals are involved in depression and may explain why exercise improves depression. Exercising therefore is like taking Prozac or Ritalin.
To benefit from the positive effect of the exercise, you have to continue exercising regularly because the new brain cells will not stay around forever. Neither will the neurotransmitters like serotonin. Studies have also shown beneficial effects in children. At school, children’s test scores have improved before examination after exercising. Hence, physical education should be mandatory for all kids in school as it helps to build their brain.
In Alzheimer disease, the hippocampus is one of the first areas of the brain to suffer damage. Does it mean that regular exercises can postpone or prevent Alzheimer disease? Time will tell. Meanwhile, it will appear that since exercise is an antidote to shrinking of the brain, you should give yourself the benefit of this elixir to fertilize your brain and keep it younger and healthier.
"The doctor of the future will give no medicine, but instead will interest his patients in the care of the human frame, in diet, and in the cause and prevention of disease."
3. The New Scientist