Dear Doctor: Our dad is 67 years old and just got a diagnosis of mild cognitive impairment. His doctor told us that getting regular exercise can help. I’ve never heard this before. Is there a scientific basis, or is the idea just for dad to stay healthy?
Dear Reader: Mild cognitive impairment, also referred to as MCI, is a worsening of the skills we use to learn, reason and remember. It affects up to one-fifth of adults over the age of 65. Although, as the name of the condition suggests, the changes to cognition are slight, they are, nonetheless, noticeable. People with mild cognitive impairment are also at increased risk of developing various types of dementia, including Alzheimer’s disease.
An area of study that continues to generate great interest is the beneficial effects exercise may have on cognition and dementia. Research that analyzes years of health and behavior data collected from specific groups of people has found that individuals who exercise regularly can measurably reduce their risk of developing dementia when they age. There is also evidence that these protective effects can carry over to people who continue to exercise in their later years.
A new study, published in November in the journal Alzheimer’s Research and Therapy, found people with MCI who did even a modest amount of exercise each day could be helping to delay the onset of more cognitive decline. Researchers examined health data collected from almost 250,000 people over the course of six years. The majority were between the ages of 65 and 70 and had been diagnosed with mild cognitive impairment. The subjects were divided into four groups: those who never exercised, those who had just begun to exercise, those who had recently quit exercising and those who had exercised prior to their diagnosis and continued to exercise regularly. Each of the groups self-reported the data about their physical activity.
Among the findings was that, when compared to the group that never exercised, those who had exercised prior to and after their diagnosis of MCI reduced their risk of progressing into dementia by 18%. For those study subjects who had begun regular exercise after receiving their diagnosis of MCI, the risk of progressing to dementia decreased by 11%.
When it came to defining physical activity, the researchers set the bar pretty low. They classified it as 10 or more minutes of moderate or vigorous exercise done more than one day per week. Not that surprisingly, they also found that exercising longer and more often conferred increased benefits. The scientists surmised exercise may have protective effects because it raises the levels of certain proteins in the brain, which help with neuron development and maintenance. They also suggested a link to the increase of blood flow to the brain during exercise. When physical activity ceased, so did the positive cognitive effects it conferred.
As with all studies with self-reported data, the conclusions rely on the accuracy of the participants’ record-keeping. Still, the physical and mental health benefits of regular exercise are well known. An exercise program tailored to your dad’s health and abilities could be helpful.
(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)
