Exercise may speed up the progress of dementia, new research suggests.
Oxford University experts found two weekly gym sessions helped improve physical fitness in older Brits with Alzheimer’s.
But not only did the four-month exercise course fail to slow down brain power loss — it accelerated it compared to inactive patients.
Previous research has found physical activity protects against developing dementia.
The British Medical Journal study involved nearly 500 patients who already had Alzheimer’s, with an average age of 77.
Nearly 330 took part in a special exercise programme, while the remaining 165 received standard care.
A year on scientists tested their brain power on a scale of zero to 70, with a high mark being worse.
Those in the active group scored 25.2, while the rest had an average of 23.8.
The study team concluded: “This indicates greater cognitive impairment [brain power loss] in the exercise group, although the average difference is small and clinical relevance uncertain.”
Lead researcher Professor Sarah Lamb, from Oxford University, said the findings raise the “possibility that some types of exercise intervention might worsen cognitive impairment [brain power loss].”
Around 850,000 Brits have dementia and the figure is expected to hit one million with a decade.
There is currently no cure but some drugs can control the symptoms.
Dr. Sara Imarisio, Head of Research at Alzheimer’s Research UK, said: “While there is good evidence to suggest that physical exercise can play an important role in reducing the risk of developing dementia, there has been little research into whether exercise could affect the progression of symptoms in people who are already living with the condition.
“This study found the exercise regimen led to an improvement in participants’ physical fitness, but this did not translate into greater independence in day-to-day activities.”
Rob Howard, professor of old age psychiatry at University College London, said exercise may harm Alzheimer’s patients.
He said: “The participants who were allocated to the exercise intervention actually showed a small worsening of cognitive functioning compared to those who didn’t exercise.
“Despite its small size, I am sure that — had this been instead an improvement in cognitive functioning with exercise — we would all have been excited about finding something positive.
“On this basis, I don’t think we should ignore the possibility that exercise might actually be slightly harmful to people with dementia.”