Exercise and Dementia
If you're looking for more reasons to keep your New Year's workout resolution, here is something that may help. More and more research is finding that dementia risk is significantly higher for sedentary middle-aged adults and that being physically fit may actually be preventative.
In 2011, the first baby boomers turned 65, an age when the risk of developing Alzheimer's disease and other forms of dementia significantly increases. One in three seniors die with dementia 18% of all boomers expected to develop Alzheimer's, a rate that is three times higher than today's. These statistics have made treating the disorders of paramount importance, and doctors have begun to embrace non-pharmaceutical alternatives, such as herbal medicine, nutrition, and exercise.
While Alzheimer's is probably the best known type of dementia, there are many others including vascular dementias, Parkinson disease, Lewy body dementia, alcohol-related dementia, and Pick disease. All forms of dementia are brain disorders characterized by deterioration in mental functioning that involves memory, concentration, problem-solving, and perception. It is not a single disorder, but actually is a group of illnesses that are progressive, meaning get worse with time. Decline in memory and cognitive function are considered a normal consequence of aging and different from dementia.
In a report published in 2013, research found that higher midlife fitness were associated with lower hazards of developing dementia later in life. For the study, investigators tracked 19,458 who took part in a series of periodic exercise treadmill tests between 1971 and 2009. The researchers reported that the participants who were in shape at middle-age significantly reduced their risk of developing dementia or Alzheimer's disease by the time they reached 65 as compared to their unfit counterparts.
The investigation looked at the participant's level of "cardiorespiratory fitness" or "CRF." CRF is considered a measure of habitual physical activity and is used as a diagnostic and prognostic health indicator. Other research has suggested that CRF is a strong predictor of and cardiovascular disease mortality.
CRF is associated with numerous health benefits, including increasing the body's ability to deliver oxygen and other nutrients to tissue and to remove waste products. Types of cardiorespiratory exercise include brisk walking, swimming, cycling, and running.
Other studies have found that exercise can delay the onset of Alzheimer's and other dementias and aerobic fitness reduces brain tissue loss in aging humans. Similarly, a study published in 2012 at University of California, Irvine found that people over the age of 90 who have poor physical performance are at increased risk of developing dementia. A physical task was defined as standing with good balance, walking, and getting up from a chair. The researchers found that even participants who even slowed down their speed of walking speeds slightly were at four times more risk of developing dementia.
This body of research highlights exercise and movement as a successful way to evade a group of disorders that currently cannot be prevented, slowed or cured. Over 5 million Americans are affected by Alzheimer's disease and according to the National Institutes of Health that number could double by 2050. Because of the detrimental effects of dementia on quality of life, finding preventable means is critical.
Colcombe S, Erickson KI, Raz N, Webb AG, Cohen NJ, McAuley E, Kramer AF. Aerobic fitness reduces brain tissue loss in aging humans. Journal of Gerontology: Medical Sciences 2002 Feb;(8A): M176-80. doi:10.1136/bjsm.2008.052498
Defina LF, Willis BL, Radford NB, Gao A, Leonard D, Haskell WL, Weiner MF, Berry JD. The association between midlife cardiorespiratory fitness levels and later-life dementia: a cohort study. Annals of Internal Medicine. 2013 Feb 5;158(3):162-8. doi:10.7326/0003-4819-158-3-201302050-00005
Larson EB, Wang L, Bowen JD, McCormick WC, Teri L, Crane P, Kukull W. 2006. Exercise is associated with reduced risk for incident dementia among persons 65 years of age and older. Annals of Internal Medicine 2006 Jan 17;144(2): 73-81. doi:10.7326/0003-4819-144-2-200601170-00004