Exercise extolled for patients with Alzheimer's, vascular cognitive impairment
Experts caution patients should consult with physicians before
Exercise may do more than keep a healthy brain fit: New research suggests working up a good sweat may also offer some help once memory starts to slide— and even improve life for people with Alzheimer's disease, vascular cognitive impairment (VCI) and mild cognitive impairment.
Doctors have long advised that people keep active as they get older. Exercise is good for the heart, which in turn is good for the brain. Lots of research shows physical activity can improve cognition in healthy older people, potentially lowering their risk of developing dementia.
With no medications yet available that can slow Alzheimer's creeping brain destruction, the new findings point to lifestyle changes that might make a difference after memory impairment begins as well. The caveat: Check with a doctor to determine what's safe for a person's overall medical condition, especially if they already have Alzheimer's.
Research from the Vancouver Coastal Health Research Institute and University of British Columbia focused on vascular cognitive impairment, or mini-strokes. Cerebrovascular disease is second only to Alzheimer's as a cause of dementia in older adults.
"Past research shows that aerobic exercise not only decreases heart health risk factors but may also improve brain structure and function," said Teresa Liu-Ambrose, Canada Research Chair in Physical Activity, Mobility, and Cognitive Neuroscience UBC and researcher at the Djavad Mowafaghian Centre for Brain Health. "[But] no intervention studies have specifically examined the usefulness of aerobic training in reducing the progression of VCI due to mini-strokes."
Liu-Ambrose reported results Thursday at the Alzheimer's Association International Conference om Washington from her team's six-month study of 71 adults with confirmed cases of VCI, their ages ranging from 55 to 96. Of the sixty-two participants who completed the study, participants who did supervised aerobic exercise three times per week for 60 minutes with certified fitness instructors significantly improved their cognitive function compared to a baseline test, including on memory and selective attention, than those who received the usual care plus an education seminar on nutrition once per month.
Functional brain scans before and after the six-month study showed that the brains of study participants became more efficient with aerobic exercise training. The activity also significantly reduced body mass index and increased functional capacity in those patients.
The study's limitations included its size and lack of diversity, but the inexpensive option helped prolong the independence and improve the quality of life of the seniors.
Targeting tau protein with exercise
Research from North Carolina is getting particular attention because it's one of the first to find exercise can affect tau, an Alzheimer's hallmark that causes tangles in brain cells.
The effects were modest, but it was found vigorous workouts by people with mild memory impairment decreased levels of a warped protein linked to risk of later Alzheimer's — and improved quality of life for people who already were in early stages of the disease.
"Regular aerobic exercise could be a fountain of youth for the brain," said cognitive neuroscientist Laura Baker of Wake Forest School of Medicine in North Carolina.
Baker studied 71 previously sedentary older adults who have hard-to-spot memory changes called mild cognitive impairment that can increase risk of developing Alzheimer's. They wore monitors to be sure the exercisers raised their heart rate enough and that the control group kept their heart rate deliberately low while doing simple stretch classes that allowed them to socialize.
MRI scans showed the exercisers experienced increased blood flow in brain regions important for memory and thought processing — while cognitive tests showed a corresponding improvement in their attention, planning and organizing abilities, what scientists call the brain's "executive function," Baker reported.
Most intriguing, tests of spinal fluid also showed a reduction in levels of that worrisome tau protein in exercisers over age 70.
"This is really exciting," said Dr. Laurie Ryan of the National Institute on Aging. "It's too soon to say that lowers risk" of worsening memory, she cautioned, saying longer studies must test if sticking with exercise makes a lasting difference.
Later this year, Baker will begin a national study that will test 18 months of exercise in people with mild cognitive impairment.
Baker said sedentary seniors can learn to exercise safely but they have to work up to it gradually, starting 10 minutes at a time.
"We baby these people," she said. "They're afraid of gyms. They don't have confidence in their own ability. We give them intensive one-on-one attention."
Meanwhile, Danish researchers reported vigorous exercise prevented neuropsychiatric symptoms — aggression, irritability, delusions — in older adults with mild Alzheimer's.
Scientists at the University of Copenhagen studied 200 older adults for four months, and didn't find overall memory improvements, although the fraction that exercised the most intensely did see some improvement in their mental speed and attention.
But improving quality of life is important because those neuropsychiatric symptoms can complicate care dramatically and are one reason that dementia patients end up in nursing homes, said NIA's Ryan.
With files from CBC News