Aerobic Exercise & The Brain

Studies exploring the relationship between aerobic exercise and brain health have produced some startling findings that are expected to have profound implications for future treatments of a wide range of conditions. Research suggests that exercise is the trigger that sets in motion the brain's capacity to self-correct various deficiencies, including those caused by age-related cognitive decline, alcoholism and radiation therapy.

Preventing Dementia and Alzheimer's Disease

A long-term study of 1,449 people aged 65 to 79, conducted at Stockholm's Karolinska Institute, found that those who had exercised at least twice a week in middle age were 50 percent less likely to develop dementia and 60 percent less likely to develop Alzheimer's disease in old age. The study, published in the October 4, 2005, online edition of "The Lancet Neurology," noted that even participants genetically predisposed to Alzheimer's, who had a history of regular aerobic exercise, were at reduced risk of developing the devastating brain disease.

Making You Smarter

Mental exercise keeps an aging brain nimble, or so people used to believe. However, a study led by neuroscientist Arthur Kramer of the Beckman Institute at the University of Illinois, Urbana, suggests that staying physically nimble might do an even better job. Published in the November 2006 "Journal of Gerontology: Medical Sciences," the study divided 59 people, aged 60 to 79, into three groups: aerobic exercisers, nonaerobic exercisers and nonexercisers. After the aerobic exercisers worked out for three months, three hours a week, the volumes of gray matter, indicating existing neurons, and white matter, indicating connections between neurons, had increased in their brains, while the brain volumes of members of the two other groups hadn't changed. The theory to account for this evidence of enhanced cognitive function involves insulin-like growth factor, or IGF, a hormone secreted by the liver that increases blood flow and promotes cell growth. Normally, IGF can't cross the blood-brain barrier, but exercise is believed to be the catalyst that allows it to penetrate.

Protection Against Alcohol-Induced Brain Damage

Overconsumption of alcohol damages parts of the brain that regulate cognitive function. A study on the effects of exercise on rats prior to their being dosed with alcohol corresponding to amounts consumed by binge drinkers found reductions both in death of brain cells and signs of intoxication. The study, led by J. Leigh Leasure of the University of Houston, was published online in the journal "Alcoholism: Clinical and Experimental Research" in December 2009. The researchers concluded that exercise protects vulnerable areas of the brain from alcohol-related cell loss. Their study may have important implications for understanding the neurobiology of alcoholism and developing new treatments.

Reversing Brain Damage from Radiation Therapy

Although radiation therapy for cancers in or near the brain increases chances of survival, it can also lead to cognitive impairments by damaging the hippocampus, a part of the brain crucial for learning and memory. A study on rats conducted by the Center for Brain Repair and Rehabilitation at the University of Gothenburg, Sweden, and published in "Proceedings of the National Academy of Sciences" in September 2008, found that running appeared to reverse radiation damage in the hippocampus by triggering regrowth of neurons. These findings may lead to improvements in rehabilitation therapies for brain cancer patients, especially children, the authors concluded.