Exercise Reduces the Risk of Alzheimer’s Disease




Physical activity is a holistic strategy for increasing overall health and lowering disease risk among a wide range of individuals, and people with neurological conditions can benefit from them too. The benefits of physical activity for individuals with, or at risk of, dementia are not particularly well known to the general public.

Alzheimer’s disease (AD) is one of the most common forms of dementia. It is still debatable what exactly causes the disease but its risk increases with age.

In 2001, the results of a study comparing the effects of physical activity on cognitive impairment were published. The findings clearly demonstrated that physical activity is associated with a reduced risk of cognitive impairment.

In this five year follow-up study involving 4,615 individuals free from cognitive impairments, it was shown that high levels of physical activity were associated with a 42% reduction in the risk of cognitive impairments in the future, suggesting that increased physical activity can benefit brain health. Similarly, high levels of physical activity were associated with a 50% reduction in AD risk and a 37% reduced risk of dementia from any other cause. This study has helped to lay the foundation for further research into the role of regular exercise in preventing the cognitive decline in older individuals.

Aerobic exercise

Aerobic exercise is one of the forms of exercise that has been shown to have beneficial effects on individuals with Alzheimer’s disease.

In a recent six-month, randomized, controlled clinical trial, it was shown that regular aerobic exercise can have a positive effect on executive functioning and other health parameters. This recent study followed 30 older individuals with an average age of 70 years for six months, with each participant randomized to either a high-intensity aerobic training (at 75-85 percent of one’s heart rate reserve) or stretching (control) group. Of these groups, the high-intensity training group was superior to the stretching group for overall functional cognition, glucose metabolism, cardiorespiratory fitness, and body composition. In addition, there appeared to be a gender specific response among the exercise group, showing that female participants were more likely to receive benefit from the six month protocol than the men.

Resistance training

Another form of exercise that is beneficial for individuals with dementia and Alzheimer’s disease is resistance training. This type of exercise, also known as strength training, is suitable for a wide range of individuals and is something that is beneficial for maintaining or improving activities of daily living.

A recent 16 week longitudinal study investigated the effects of a strength training program among 34 individuals with AD on daily activities. It was found that a regular strength training program improved such daily activities as climbing stairs, walking and moving around the house, getting up from the floor, and putting on socks. Improvements in such small tasks significantly improve the quality of life of older person, especially if he or she is suffering from Alzheimer’s.

Strength training is also the best known way to increase muscle mass in the human body. Studies have shown that AD is associated with the loss of muscle mass. This underscores the importance of regular strength training for individuals at risk or diagnosed with AD.

Studies exploring the possible association between muscle mass and the prevalence of AD have shown similar results. In a recent study examining 900 individuals without dementia it was found that there was a decreased risk of dementia and AD when the individual has greater muscular strength. This suggests that a lifelong program dedicated to exercise and resistance training can help prevent and reduce the risk of developing neurodegenerative disorders.

The two combined

When resistance training and aerobic conditioning are combined, the effects are improved even further. In fact, research has shown that combining the two forms of exercise can be a great way to prevent cognitive decline.

Current research on exercise programs consisting of strength and aerobic training has shown the benefits of one year exercise programs among individuals who have mild to moderate dementia. In addition, individuals in this study with a higher cardiorespiratory fitness, or overall fitness level, showed lower levels of atrophy in the brain due to an exercise program, thus demonstrating that exercise can help maintain brain size.

The overall benefits of exercise on health are numerous and well known. The effects of exercise on brain health and wellness have not received much attention of researchers until recently. Current data clearly point to its benefits.

Regular exercise which incorporates walking, jogging, biking, swimming, stretching, and skipping can all have benefits to help slow the progression of the condition. In addition, regular resistance training at least two days per week at a moderate intensity of at least 50 percent of one’s maximum can have lasting effects on brain health.

Understanding the importance of being active for overall health is crucial at any age, but it is especially important for older adults. Creating a daily routine inclusive of aerobic and strength training can help maintain brain size and efficiency for the overall prevention of Alzheimer’s disease risk.

References

Baker LD, Frank LL, Foster-Schubert K, Green PS, Wilkinson CW, McTiernan A, Plymate SR, Fishel MA, Watson GS, Cholerton BA, Duncan GE, Mehta PD, & Craft S (2010). Effects of aerobic exercise on mild cognitive impairment: a controlled trial. Archives of neurology, 67 (1), 71-9 PMID: 20065132

Balsamo S, Willardson JM, Frederico Sde S, Prestes J, Balsamo DC, Dahan da CN, Dos Santos-Neto L, & Nobrega OT (2013). Effectiveness of exercise on cognitive impairment and Alzheimer’s disease. International journal of general medicine, 6, 387-91 PMID: 23737675

Boyle PA, Buchman AS, Wilson RS, Leurgans SE, & Bennett DA (2009). Association of muscle strength with the risk of Alzheimer disease and the rate of cognitive decline in community-dwelling older persons. Archives of neurology, 66 (11), 1339-44 PMID: 19901164

Garuffi M, Costa JL, Hernández SS, Vital TM, Stein AM, dos Santos JG, & Stella F (2013). Effects of resistance training on the performance of activities of daily living in patients with Alzheimer’s disease. Geriatrics & gerontology international, 13 (2), 322-8 PMID: 22726761

Hurley BF, Hanson ED, & Sheaff AK (2011). Strength training as a countermeasure to aging muscle and chronic disease. Sports medicine (Auckland, N.Z.), 41 (4), 289-306 PMID: 21425888

Laurin D, Verreault R, Lindsay J, MacPherson K, & Rockwood K (2001). Physical activity and risk of cognitive impairment and dementia in elderly persons. Archives of neurology, 58 (3), 498-504 PMID: 11255456

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Viatcheslav Wlassoff, PhD

Viatcheslav Wlassoff, PhD, is a scientific and medical consultant with experience in pharmaceutical and genetic research. He has an extensive publication history on various topics related to medical sciences. He worked at several leading academic institutions around the globe (Cambridge University (UK), University of New South Wales (Australia), National Institute of Genetics (Japan). Dr. Wlassoff runs consulting service specialized on preparation of scientific publications, medical and scientific writing and editing (Scientific Biomedical Consulting Services).
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