Positive developments in health – including reduced smoking, better diets and increased exercise – are pinpointed for a dramatic fall in dementia rates among elderly males in the United Kingdom.
A new Cambridge University study on dementia trends of the past two decades found a 20 percent fall, which translated to about 40,000 fewer cases of the condition than previously estimated.
The surprising dip, however, was seen mainly in men and not in women, which had a much smaller reduction in dementia cases.
“Our evidence shows that the so-called dementia ‘tsunami’ is not an inevitability: we can help turn the tide if we take action now,” said Cambridge Institute of Public Health Director Carol Brayne, whose findings suggest that brain health has been improving substantially in the country, particularly among men.
The team replicated a study first executed by more than 7,600 people over age 65 from 1989 to 1994 from sites around the UK. They then used the same questions for assessing the mental health of more than 7,700 individuals between 2008 to 2011 from three of the original research sites.
The researchers saw dementia rates fall by nearly half for men ages 85 and above, from 71 in 1,000 in the early 1990s to 38 in 1,000 in the recent study. There was also a drop from the anticipated 250,000 new dementia cases per year to just under 210,000 – or 74,000 males and 135,000 females.
The overall incidence rates dipped from 20 dementia cases for every 1,000 people in the early '90s to 17.7 cases per 1,000 recently.
Likely driving the reduced rates, according to the authors, are public health measures for improved health, including reducing or quitting smoking, paying attention to one’s diet and exercise.
For Professor Fiona Matthews of Cambridge and Newcastle University, these measures are important and are more cost-effective in the long term than diagnosing dementia early and treating it once already present.
Some experts, however, are seeking further explanation on why dementia rates have fallen among the male population.
“This can’t be explained just from improved vascular risk management or lifestyle changes,” argued psychiatrist Dr. Sujoy Mukherjee from West London Mental Health Trust, explaining that the diagnostic tools employed – including interviews and the Mini Mental State Examination raise doubts on the validity of the team’s approach and, therefore, the results.
He said the time of the study as well as the lack of a “robust protocol” could have missed a number of patients who would have probably received a dementia diagnosis based on current clinical practice.
He cited, for instance, the advanced dementia state of some subjects and their lack of ability to answer some questions, which is unlike current practice where patients are referred much earlier and receive diagnosis at an early stage.
For University College London's John Hardy, a neuroscience professor, the difficult question now is what is exactly prompting the reduction in men. The most apparent changes, he said, are related to vascular health, including cholesterol control and smoking cessation.
“Clearly, these issues deserve further careful study, but this study suggests some good news,” he added.
The findings were published in the journal Nature Communications.
Photo: Sjoerd Lammers | Flickr
