Dementia remains a mystery with still a 'lot to learn'

One of the biggest ever studies on the prevention of dementia has concluded that the condition is still a mystery, with one of the authors saying 'there is no magic bullet’.

The US report ‘Physical Activity Interventions in Preventing Cognitive Decline and Alzheimer-Type Dementia’ looked at 116 significant previous trials that studied the effect of exercise, vitamin supplements, cognitive training and other ‘wellness regimes’ to determine whether or not dementia could be delayed.

The study revealed that there was no proof that any of these interventions prevented dementia in later life.

Researchers did find that brain training has a slight beneficial effect but not as a tool to avoid getting dementia later in life. It also needs to be undertaken as part of a group.

There is no ‘magic bullet’ to prevent dementia

Report co-author, Dr Mary Butler, said: "There is no magic bullet. But those areas where we did find potentially positive findings are very consistent with public health types of messages we hear all the time. Live a healthy life, eat a good diet, stay cognitively active and engage socially."

The study by the University of Minnesota looked at past research on the prevention of dementia.

Cognitive training, exercise and diet ‘showed some improvement’

The report’s conclusion was that there wasn’t strong enough evidence that any of the ‘interventions’ studied had any real effect on the progression of dementia, although if they were combined, some had a very minimal effect.

Co-author of the study, Dr Howard Fink said: ''We looked at drugs, over-the-counter vitamin supplements, exercise, cognitive training and overall the results didn't show much benefit."

He added: "One of several of the studies that looked at the effect of combining specific interventions - cognitive training, exercise and diet - showed some improvement in cognitive outcomes."

Looking at group 'brain training', researchers found people improved in the areas that they trained in, but that training did not extend to other areas. Dr Butler explained, “So, for example, if you trained in processing speed, there wasn't an improvement in memory.”

‘It’s a humbling result, and we have a lot to learn’

According to Alzheimer’s Research UK, the numbers of people living with dementia globally will increase from 46.8 million in 2015 to 131.5 million in 2050. This is a 281 per cent increase.

However, the authors of the report do point out that whilst they haven’t been able to find much concrete proof for stopping the onset of dementia, this might be because of the nature of the condition.

They propose that trials start earlier and progress over a much longer time. Dr Fink said: “We believe that Alzheimer's develops over many years. And these interventions may not have been started early enough, or continued long enough, but there were also some problems with the studies about the way they measured cognition."

He continued, “It’s a humbling result. It tells us that we have a lot to learn.”

Dr Butler also acknowledged that it is hard to do research trials on dementia prevention. Her conclusion was: “It's difficult to interpret exactly what a failure, or a no finding really suggests. The studies themselves had problems with how they were conducted. They're difficult studies to do, in all fairness to the researchers.”

The study was published in the American medical journal, the ‘Annals of Internal Medicine’.