THURSDAY, May 17, 2018 (HealthDay News) -- A new study suggests that moderate or even rigorous exercise won't slow mental decline in older people with dementia.
People with early dementia were able to follow an exercise regimen and boost their physical fitness. But that did not translate into "improvements in cognitive impairment, activities in daily living, behavior, or health-related quality of life," according to British researchers at the University of Oxford.
Still, the conclusions run counter to prior research that's shown how exercise can help the aging brain. So, experts who reviewed the study say more and better research may be needed.
In the study, a team led by Sarah Lamb, of Oxford's Center for Rehabilitation Research and Center for Statistics in Medicine, tracked outcomes for nearly 500 people averaging 77 years of age. All patients had been diagnosed with mild or moderate dementia and were enrolled in aerobic exercise and strength training regimens.
The overall health and fitness level of each person was assessed when the study began. Then, 329 of the volunteers were assigned to a supervised exercise and support program while 165 patients continued to receive their usual care.
Those in the exercise group completed 60- to 90-minute workout sessions in a gym twice per week for four months. They also performed home exercises for another hour each week and received consistent support.
At six months and again at 12 months, the researchers assessed the participants' adherence to their assigned regimen. They also analyzed the progression of the patients' dementia, as well as the number of falls they sustained and their overall quality of life.
During the 12-month study, all of the participants continued to experience mental decline, according to the study published May 16 in the BMJ. Those in the exercise group became more physically fit, but their dementia scores were actually slightly worse than the patients who received their usual care.
There was also no difference in the number of falls or the quality of life among the two groups, the researchers said in a journal news release.
But two U.S. experts in brain health said the study had flaws, and exercise might still help people with early dementia.
"The design of the study was not ideal, and the conclusion that all fitness interventions do not alter rates of decline in people with dementia is not supported," said Dr. Jeremy Koppel. He's a Alzheimer's researcher at the Feinstein Institute for Medical Research in Manhasset, N.Y.
Koppel believes there was too little supervision of the study participants to be sure they were doing the exercise as recommended. "The study also mixed strength training with aerobics, potentially limiting the ability of participants to gain muscle weight," he added.
Dr. Gayatri Devi is a neurologist and memory disorder specialist at Lenox Hill Hospital in New York City. She said numerous studies have shown that exercise has benefits for brain cell health, including the growth of new cells in the hippocampus, the brain's memory center.
She agreed with Koppel that better supervision might have uncovered a benefit for certain people.
"It is possible that some patients, better able to follow directions, may have benefited from the exercising, while others did not," Devi said. "In my opinion, further research is needed in this area and possibly individual programs tailored to the needs of individual patients."
The U.S. National Library of Medicine provides more information on dementia.