Taking a brisk walk or engaging in other moderate-intensity physical activities may help slow down the progression of Alzheimer’s disease in people who are already at a risk of developing the disorder.
Alzheimer’s disease, also referred to simply as Alzheimer’s, is a chronic neurodegenerative disease that usually starts slowly and worsens over time. It is the cause of 60% to 70% of cases of dementia.
The most common early symptom is difficulty in remembering recent events short term memory loss. As the disease advances, symptoms can include problems with language, disorientation including easily getting lost, mood swings, loss of motivation, not managing self care, and behavioural issues.
As a person’s condition declines, they often withdraw from family and society. Gradually, bodily functions are lost, ultimately leading to death. Although the speed of progression can vary, the average life expectancy following diagnosis is three to nine years.
The cause of Alzheimer’s disease is poorly understood. About 70% of the risk is believed to be genetic with many genes usually involved. Other risk factors include a history of head injuries, depression, or hypertension. The disease process is associated with plaques and tangles in the brain.
A probable diagnosis is based on the history of the illness and cognitive testing with medical imaging and blood tests to rule out other possible causes. Initial symptoms are often mistaken for normal ageing. Examination of brain tissue is needed for a definite diagnosis. Mental and physical exercise, and avoiding obesity may decrease the risk of Alzheimer’s disease.
In 2015, there were approximately 29.8 million people worldwide with AD. It most often begins in people over 65 years of age, although 4% to 5% of cases are early-onset Alzheimer’s which begin before this. It affects about 6% of people 65 years and older. In 2015, dementia resulted in about 1.9 million deaths.
It was first described by, and later named after, German psychiatrist and pathologist Alois Alzheimer in 1906. In developed countries, Alzheimer’s disease is one of the most financially costly diseases.
Dr. Aloysius “Alois” Alzheimer was a German psychiatrist and neuropathologist and a colleague of Emil Kraepelin. Alzheimer is credited with identifying the first published case of “presenile dementia”, which Kraepelin would later identify as Alzheimer’s disease.
Researchers from University of Wisconsin-Madison in the US studied about 93 members of a parental history Alzheimer’s risk study group. They measured the daily physical activity of participants, all of whom were in late middle-age and at high genetic risk for Alzheimer’s disease, but presently show no cognitive impairment.
Activity levels were measured for one week, quantified, and analysed. This approach allowed researchers to determine the amount of time each subject spent engaged in light, moderate, and vigorous levels of physical activity.
Light physical activity is equivalent to walking slowly, while moderate is equivalent to a brisk walk and vigorous a strenuous run. Data on the intensities of physical activity were then statistically analysed to determine how they corresponded with glucose metabolism – a measure of neuronal health and activity – in areas of the brain known to have depressed glucose metabolism in people with Alzheimer’s disease.
Researchers measured brain glucose metabolism using a specialised imaging technique called 18F-fluorodeoxyglucose positron emission tomography (FDG-PET). They found moderate physical activity was associated with healthier (greater levels of) glucose metabolism in all brain regions analysed.
Researchers also noted a step wise benefit: subjects who spent at least 68 minutes per day engaged in moderate physical activity showed better glucose metabolism profiles than those who spent less time.
“While many people become discouraged about Alzheimer’s disease, these results suggest that engaging in moderate physical activity may slow down the progression of the disease,” said Ryan Dougherty from University of Wisconsin- Madison. The study was published in Journal of Alzheimer’s Disease.