THE BLOG
08/26/2013 05:09 pm ET Updated Oct 26, 2013

Foreign Studies Show Decline In Dementia

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Three foreign studies were released recently that seem to suggest that rates of dementia are decreasing and will continue to decrease over time. Below is a summary of all the findings from the studies, which were published in France, England and Denmark.

FRANCE

Researchers in France conducted a study of nearly half a million people and found that the risk of dementia is decreasing. They looked at over 429,000 of the country's detailed health records of the self-employed who pay into a public healthcare system. Most of them were skilled workers, such as shopkeepers, bakers and woodworkers, who were around the age of 74 and had been retired for roughly 12 years.

Work Longer
"For each additional year of work, the risk of getting dementia is reduced by 3.2%," said Carole Dufouil, a scientist at INSERM, the French government's health research agency.

  • People who push their retirement age have a lower risk of developing Alzheimer's disease or other types of dementia
  • Working tends to keep people physically and socially active and mentally stimulated, all things known to help prevent mental decline.
  • Someone who retired at 65 had about a 15% lower risk of developing dementia compared to someone retiring at 60

France has a mandatory retirement age of 65 for civil servants, but Dufouil said that this new study suggests "people should work as long as they want" because it may have health benefits."

ENGLAND

A study conducted by British researchers at the Cambridge Institute of Public Health has found that dementia rates among people 65 and older in England have plummeted by 25 percent over the past two decades. The researchers randomly selected 7,635 people, ages 65 and older, to examine for dementia between 1984 and 1994. Then, between 2008 and 2011, the researchers assessed a similar randomly selected group living in the same areas. Rates dropped from 8.3 percent to 6.2 percent.

Health Education
The study may suggest a trend that researchers say is probably occurring across developed countries and that could have major social and economic implications for families and societies.

  • Many experts thought that dementia rates would fall and mental acuity improve as the population grew healthier and better educated.
  • The incidence of dementia is lower among those with a better education, as well as among those who control their blood pressure and cholesterol, possibly because some dementia is caused by mini strokes and other vascular damage.
  • As populations better controlled cardiovascular risk factors and had more years of schooling, it made sense that the risk of dementia might decrease, proving what the experts had hypothesized.

DENMARK

A study conducted in Denmark found that people in their 90's who were given a standard test of mental ability in 2010 scored substantially better than people who were in their 90's in 1998. About 25% of the participants observed in 2010 scored at the highest level, which was double the amount of high-level responses from those tested in 1998.

Performed by the University of Southern Denmark in Odense, researchers compared the physical health and mental operation of two groups of elderly Danish people. The first group of 2,262 people, were born in 1905 and were assessed at age 93. The second group of 1,584 people, were born in 1915 and assessed at age 95. In addition to examining the participants for physical strength and vigor, the researchers gave them a standard dementia screening test and several other cognitive tests.

Declining Numbers
  • The study suggests that more people are living to older ages with better overall functioning.
  • They discovered that the curve of people who scored high had scores indicating dementia or were somewhere in-between was shifted upward among the people born in 1915
  • The percentage of subjects severely impaired fell to 17 percent from 22 percent.

So, what do you think these numbers could mean for U.S. rates of dementia?