There have been hints of this before from various studies over the years, but new research has confirmed that the number of people being diagnosed with dementia is dropping, despite experts warning over two decades ago that as we live longer, the rate should actually increase. Published in Nature Communications, this latest study goes some way to show that the condition can actually be prevented, and is not as inevitable as many used to think. Yet the researchers still warn about becoming complacent, because despite the decline seen, over 200,000 people a year are still being diagnosed with the condition.
The study began when the researchers interviewed, and then followed up two years later, 5,156 participants over 65 in the early 1990s, and then using the same questions, interviewed and followed up 5,288 people between 2008 and 2013. The same methodology allowed for direct comparisons between the two studies, and found that the rate of new dementia cases in the U.K. fell dramatically over the two decades, from 20.1 cases in 1,000 during the 1990s, to 17.7 20 years later.
The impressive drop in incidence of 20 percent is actually mostly attributed to the rate of the condition in men between the ages of 70 to 74 dropping from 12.9 in every 1,000 to 8.7, and even more impressively over halving in those men above the age of 80. While the researchers in this study didn’t look at what might be driving this decrease, it’s been suggested that it is probably related to better education, a reduction in smoking, greater brain health, and just people leading generally healthier lifestyles. In women, the picture from the study is a little more confused.
While for those women in the 80 to 84 age group actually showed a slight increase in rates of dementia over the 20-year time span, all other groups did show a decrease, but nothing near the rates seen with men. Some propose that this could be due to the fact that the rate in women has already been reduced as far as it can by changes in lifestyle alone, and that they have simply reached a plateau, while others are now asking if there is another factor at play bolstering the number of dementia cases in women.
“There have been a number of studies suggesting that the rate of dementia in the elderly is dropping although the number of elderly is increasing,” explains John Hardy, Professor of Neuroscience at University College, London, who was not involved with the study. “This study is the most convincing of such studies and seems to show that this improvement over the last 20 years is restricted to men. An important and difficult question is what is behind this improvement: if we knew that we could perhaps improve more and help reduce the incidence in women too.”
Yet people should not get complacent by this news, as there are still scores of people who will have to live with this condition. “However, people are living for longer and with other risk factors such as diabetes and obesity on the rise, there will still be over 200,000 new cases of dementia each year,” warns Dr. James Pickett, the Head of Research at the Alzheimer’s Society. “That’s still an enormous number of people who require better information and health and social care support.”
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