More than 16 million people in the United States live with cognitive impairment. The underlying cause of vascular cognitive impairment, in particular, is caused by problems with blood supply to the brain. Scientists may have found a solution to prevent memory decline in people with this condition, in the form of regular exercise.
Vascular cognitive impairment (VCI) is the second leading cause of dementia - after Alzheimer's disease - accounting for around 10 percent of cases. People with VCI experience deterioration in mental abilities, such as memory, thinking, problem-solving, and language.
VCI develops as a result of reduced blood flow to the brain that damages and eventually kills brain cells. The death of brain cells causes problems with cognition - memory, thinking, and reasoning.
Blood flow can diminish due to narrowing and blockage of small blood vessels deep in the brain, through a major stroke, or many mini strokes. In many of these cases, these difficulties are linked to underlying health conditions, including high blood pressure and diabetes, and lifestyle choices such as smoking and being overweight.
While there is no specific treatment for VCI or a method to reverse the damage caused to the brain, there are ways to slow down the progression of the condition. Lifestyle changes - such as eating healthily, weight loss, quitting smoking, and regular exercise - can also tackle the underlying cause of high blood pressure.
"Studies have shown that exercise can help reduce the risk of developing memory problems, but few studies have looked at whether it can help people who already have these problems get better or keep from getting worse," says study author Teresa Liu-Ambrose, Ph.D., of the University of British Columbia in Vancouver, Canada.
Liu-Ambrose and team aimed to assess what effect an aerobic exercise-training program would have on cognitive and everyday function among 70 adults with VCI with an average age of 74 years.
The study findings were published in Neurology, a medical journal of the American Academy of Neurology.
The participants were divided into two groups. One group took part in 1-hour exercise classes three times a week for 6 months, while the other group received monthly information about VCI and a healthy diet, but no information on regular exercise.
Exercise improved thinking, blood pressure, cardiovascular capacity
Overall thinking skills, executive function skills - such as planning and organizing and how well daily tasks were completed - were assessed in participants before the study, on study completion, and then again 6 months later.
Compared with the non-exercise group, the training group experienced blood pressure improvement and improved on a test to measure overall cardiovascular capacity by logging the distance they could walk in 6 minutes. This finding is important as high blood pressure is a risk factor for developing VCI, say the researchers.
The research team discovered that the people in the exercise-training group improved on the overall thinking test by 1.7 points, compared with those who took part in zero physical activity.
"This result, while modest, was similar to that seen in previous studies testing the use of drugs for people with vascular cognitive impairment. However, the difference was less than what is considered to be the minimal clinically important difference of three points."
Teresa Liu-Ambrose, Ph.D.
When the training group was assessed after 6 months - on cessation of the exercise program - their scores were the same as those people who had not exercised. No differences were observed between the two groups, during any of the assessment stages, for tests of executive function skills and daily activities.
In an accompanying editorial, Dr. Alexandra Foubert-Samier, Ph.D., says that despite the limitations of the study, "the results of this work provide a proof of concept of the effect of physical activities on cognition in patients with VCI and encourage further studies on larger groups of people with VCI."
Future work may test further whether exercise can improve thinking skills in VCI. Larger samples may detect differences in specific thinking abilities such as a person's ability to plan and manage their finances.