A landmark international study shows how we can get started
It’s a prediction we are unlikely to have heard before. We, as individuals and as societies, can take action now to prevent or slow down the spread of dementia in our population – a looming opportunity that would mark a turning point in mankind’s search for ways to tame this feared disease.
In England last month the Lancet Commission – an international panel of prominent disease experts, released a landmark study, Dementia Prevention, Intervention and Care, to consolidate and bring more insight to the vast amount of information produced in recent medical research. The panel found that “huge strides” had been made in expanding knowledge of the disease.
As the panel noted, dementia occurs mainly in people older than 65 years. But dementia is not an inevitable part of growing old and in some populations – including Canada – its onset is already being delayed for years as a result of lifestyle changes. More, data from the populations so blessed opens up a critical finding: that less dementia risk in successive generations would result from a lifetime exposure to positive health and lifestyle conditions.
And out of this data and some complex calculations, came the commission’s key listing of nine “potentially reversible risk factors” that with modifications could lower today’s projected numbers of dementia patients.
It is now recognized that dementia, which brings on memory loss, lack of cogent thought, inability to function and much more, exists in the body for a decade before it produces its known symptoms. It can‘t be cured, but by eliminating or modifying a risk, its manifestation can be delayed, possibly throughout an individual’s remaining lifetime.
Bringing together the available evidence about the impact of modifying risky elements in an individual’s life, the commission produced figures showing how, with a (theoretical, never-to-be-achieved) maximum elimination of risk in each case, individuals could lower their risk of contracting the disease. See table (left).
The commission’s work to date focuses largely on well-established, modifiable risk factors affecting the heart system, including diabetes, midlife hypertension, midlife obesity, physical activity and smoking. “Prevention is better than cure,” the commission observes, “and underlies the growing interest in modifiable risk factors.”
There is, the Lancet study tells us, another key factor in play affecting the onset of dementia. Recent community based studies in the United States have found that some individuals who are mentally healthy can tolerate a heavy burden of diseases of the nervous system. From this finding, the concept of “cognitive reserve” was born: people who have brain reserve, it states, can tolerate a greater amount of vascular and nervous system disorders without damage to their thinking and ability to function. It is now widely believed that a person’s ongoing exposure to factors which increase this reserve, namely physical exercise, intellectual stimulation or leisure activities, lowers the risk of dementia in their later life.
Following up on this premise, the commission declares that a broader approach to preventing dementia, including actions to promote resilience, makes sense in our aging societies. Healthier lifestyles have been shown to go hand in hand with a decline in late-life dementia, it notes.
Bringing these two approaches together, the commission observes that improvement in brain reserve combined with interventions affecting cardiovascular risk are ways to help people bounce back from their affliction.
In 2015, around 47 million people were living with dementia on this planet, a number that is expected to increase to 66 million by 2030 and 131 million by mid-century. The disease is estimated to cost the world $818 billion US annually.
The world has been taking notice. The (then G8) health ministers meeting in London in December 2013 agreed to strength their efforts to meet the challenges of the disease. The World Health Organization in March 2015 organized a first ministers’ conference on Global Action Against Dementia, and announced establishment of a global observatory for monitoring the world’s progress in battling the disease. Delegates to the Seventieth World Health Assembly in May committed to developing and implementing national strategies.
There is much yet to be learned about dementia, and its workings, but the Lancet Commission tells us we already know a great deal. Action now on what we already know about dementia can transform the future of society.