Recent research has identified at least three different ways in which exercise can help our brains.
These include helping the brain control hunger; increasing the blood flow in important areas of the brain; and specifically helping memory functions.
Hunger
Two sets of hormones impact hunger ... ghrelin, which sends information to the brain when energy is running low, and two kinds of peptides, within the brain, which signals whether or not the body needs food.
Dr. Amy Rothberg, an assistant professor of internal medicine at the University of Michigan, directs their Weight Management Clinic. Rothberg describes ghrelin as the "hunger hormone"--a hormone which is generated in response to internal signals that the body needs fuel. This physical feeling of hunger is referred to as homeostatic - that is, the body is working to maintain its internal stability.
Within the brain, there are hunger-stimulating ("orexigenic" or PYY) peptides, and hunger-suppressing ("anorexigenic" or GLP-1) peptides. These peptides are hormones that are responsible for telling the brain that a person needs to eat, or that a person's need for food is satisfied.
The best way to satisfy homeostatic feelings of hunger is to eat, and Rothman points out that protein is the most filling of the macronutrients. And, another study, reported in the Journal of the Academy of Nutrition and Dietetics, concluded that what we would expect does, in fact, happen: eating larger amounts of protein produces more feelings of fullness than eating smaller amounts of protein.
But now that we have begun to understand how hormones generate feelings of hunger, there is a question as to whether there are ways besides eating, relating to these hormones, to suppress feelings of hunger.
Dr. David Stensel, at the U.K.'s Loughborough University, ran a study that concluded that an intense exercise workout can indeed lower the body's levels of ghrelin, which then raises the level of peptide YY, the hunger-suppressing hormone ... for a short while. And studies at the Energy Metabolism Laboratory at the University of Massachusetts conducted by its director, Barry Braun, supports that conclusion. More research in this arena is needed to understand how exercise generates that effect, and then to develop a way of using that information to help suppress feelings of hunger.
Blood Flow in the Brain
There is a reduction in the size of certain areas of the brain that is linked to Alzheimer's disease.
A study was undertaken to see whether exercise could have an impact on increasing the size of those areas. Kathleen Reiter, a member of the team that did the study, reported an increase of approximately eight and a half percent in the part of the brain that are responsible for language comprehension, awareness, and memory.
A study was undertaken to see whether exercise could have an impact on increasing the size of those areas. In an article on the notes that Kathleen Reiter, a member of the team that did the study, reported an increase of approximately eight and a half percent in the part of the brain that is responsible for language comprehension, awareness, and memory.
Helping Memory Functions
Another protein generated by our bodies, called cathepsin B, was shown in experiments on rodents, and then on monkeys, to cause the growth of new cells and connections in the hippocampus, an area of the brain that is of key importance to memory. Henriette van Praag, who investigates brain science at the National Institute on Aging, has now reported similar results in a small test of 33 people.
These studies tell us that, while we are still in the early stages of identifying exactly how exercise impacts the brain, further investigations may help us more fully identify how to use exercise to combat brain diseases and improve brain functioning.