Dementia

Regular Exercise Reduces Risk of Developing Dementia

Starting to exercise after dementia starts does not improve memory

Posted May 24, 2019

Regular exercise enhances neural plasticity and promotes new synapse formation

Physical exercise increases levels of a naturally occurring substance in the brain, brain-derived neurotrophic factor, which enhances neural plasticity and stimulates the formation of new synapses. Regular exercise is associated with increases in the relative size of the frontotemporal and parietal lobes, which are important centers for learning, memory, and executive functioning (Haier, 1993) (reference listed below). Regular physical activity over the long-term such as walking, cycling and running, is associated with reduced risk of Alzheimer’s disease and other types of dementia. However, there is no consensus on the optimal type, frequency or duration of exercise for reducing the risk of developing dementia (Stephen 2017). There is lower risk of developing Alzheimer’s disease when physical exercise is combined with the Mediterranean diet (Scarmeas 2009).

Exercise is equally beneficial for elderly men and women

In a 10-year study, over 2000 healthy elderly men ages 71 to 93 years were followed with routine neurological assessments at 2-year intervals starting in 1991 (Abbott, White, Ross, Masaki, Curb, & Petrovitch, 2004). At the end of the study period, men who walked less than 0.25 mile daily had an almost twofold greater probability of being diagnosed with any category of dementia (including Alzheimer’s disease and vascular dementia) compared with men who walked at least 2 miles each day. Factors other than the level of physical activity were accounted for, including the possibility that limited activity could be a result of early but undiagnosed dementia. Findings of the Nurses’ Health Study based on biannual mailed surveys over 10 years showed that elderly women ages 70 to 81 years who engaged in regular vigorous physical activity were significantly less likely to have been diagnosed with dementia compared with women with more sedentary lifestyles (Weuve et al., 2004).

Starting to exercise after dementia has started doesn’t improve cognitive functioning

Although regular exercise is an important preventive strategy, it is probably not an effective intervention once dementia has started. A randomized controlled trial showed that regular daily exercise in moderately demented individuals receiving in-home care reduces depressed mood, but it does not improve cognitive functioning (Teri et al., 2003).

Bottom line

Regular exercise stimulates brain growth and new synapse formation. Research findings support that healthy adults who engage in regular exercise over a long period of time have significantly reduced risk of developing Alzheimer’s disease and other types of dementia. However, starting to exercise after dementia has started probably does not reduce the risk of developing dementia.

Regular exercise such as walking and cycling is safe especially when done at a moderate level of intensity. Individuals who have a serious medical condition such as heart disease or high blood pressure, should consult with their physician before starting a strenuous exercise routine. 

References

Haier, R. (1993). Cerebral glucose metabolism and intelligence. In P. A. Vernon (Ed.), Biological approaches to the study of intelligence (pp. 318–332). Westport, CT: Ablex Publishing Corp

Haier, [VGC1] R. (1993). Cerebral glucose metabolism and intelligence. In P. A. Vernon (Ed.), Biological approaches to the study of intelligence (pp. 318–332). Westport, CT: Ablex Publishing Corp

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