Spring Arbor Living Blog

Even moderate exercise can increase the size of your brain. The best thing you can do to keep your brain healthy is to get off the couch go for a brisk walk. Just one year of walking three times a week can increase the size of the hippocampus, a part of the brain that's key to memory.

Scientists know that the hippocampus begins to shrink as we age, leading to impaired memory and an increased risk of dementia. Researchers have shown that aerobic exercise can reverse the shrinkage and improve memory, a finding that builds on past evidence pointing to a relationship between fitness and brain function.

"This important study goes well beyond saying that exercise is good for older people, a statement that often leads people to roll their eyes and say, 'Of course,' " says Columbia University neurologist Scott Small, M.D. "It links exercise specifically to a way in which aging affects the brain and clearly establishes a means to slow the onset of age-related memory loss."

For the study, researchers from the University of Pittsburgh, the University of Illinois, Rice University and Ohio State University recruited 120 sedentary older people without dementia.

The men and women, 55 to 80 years old who in the previous six months had participated in less than one weekly session of physical activity lasting at least 30 minutes.

The participants were randomly assigned to one of two supervised groups, either an aerobic exercise program of walking around a track for 40 minutes a day, three days a week, or a program of yoga and toning with resistance bands. They provided blood samples, had MRI brain scans and took memory tests at the beginning of the one-year study, after six months and at the end.

After the study ended, brain scans showed that the hippocampus had increased in size by about 2% among the walking group, which effectively reversed age-related loss by one to two years, while it shrank by about 1.4% in the stretching group. The exercise group also showed improved performance on a memory test and increased levels of BDNF, a protein involved in learning and memory.

This is an inexpensive and painless way to improve memory and brain health. All you need is a good pair of shoes.

AARP

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Alzheimer's disease symptoms result from physical changes in the brain. What causes these changes is still somewhat of a mystery, however researchers have a leading theory of how the Alzheimer's disease progresses.
 
In a healthy brain, certain chemical processes ensure the proper functioning of neurons. One is the processing of amyloid precursor protein (APP) that is attached to the outer membrane of nerve cells. Certain enzymes cut off a section of the protein; while another enzyme snips a second portion and releases APP from the cell’s membrane.

These APP fragments are then broken down and removed from the brain. Another process, which we won’t get into here, carries nutrients through the nerve cells to keep them functioning normally.
 
When the processes that keep a healthy brain functioning go awry, a different enzyme, cuts shorter APP fragments from the nerve cell membrane. These smaller pieces are more resistant to breakdown and tend to clump together in toxic clusters and eventually they collect into plaques that interfere with nerve cell functioning. Within neurons, the transport of nutrients is crippled and nerve cells are destroyed. Loose threads join together to form knotted strands inside neurons. These cause further neuron destruction.

In the early stages of Alzheimer’s, plaques and tangles form in brain areas responsible for learning, thinking, and planning -- in particular, the hippocampus. This is why forgetfulness, disorientation, and verbal repetition are often among the earliest signs of Alzheimer’s. As nerve cell destruction spreads more brain areas are affected, especially the cerebral cortex, responsible for language, reasoning, and judgment. Speaking skills become impaired and emotional outbursts grow more frequent.

When large areas of nerve cells die off in the advanced Alzheimer’s stage, brain sections atrophy and the whole brain shrinks to as much as three quarters of its original size. People with Alzheimer’s lose most of their ability to communicate, walk, and care for themselves.  

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