People developing dementia earlier and dying of it more: study

WASHINGTON — People are developing dementia a decade before they were 20 years ago, perhaps because of environmental factors such as pollution and the stepped-up use of insecticides, a wide-ranging international study has found.

The study, which compared 21 Western countries between the years 1989 and 2010, found that the disease is now being regularly diagnosed in people in their late 40s and that death rates are soaring.

The study was published in the Surgical Neurology International journal, and its findings publicized in the London Times newspaper Thursday.

The problem was particularly acute in the United States, where neurological deaths in men aged over 75 have nearly tripled and in women risen more than fivefold, the leader of the study, Colin Pritchard from Bournemouth University, told the London Times.

Scientists quoted in the study said a combination of environmental factors such as pollution from aircraft and cars as well as widespread use of pesticides could be the culprit, the newspaper reported.

Early-onset dementia used to cover people developing the disease in their late 60s. Now, it’s meant to mean people much younger than that, the research showed.

The study found that deaths caused by neurological disease had risen significantly in adults aged 55 to 74, virtually doubling in the over-75s.

Some 60 per cent of the increase in deaths was attributed to dementias. Some 40 per cent covered other neurological diseases such as Parkinson’s and motor neurone disease, scientists told the London newspaper.

The sharp increase in death rates from dementia-related diseases cannot simply be blamed on an aging population or stepped-up diagnosis, Pritchard said.

“The rate of increase in such a short time suggested a silent or even a hidden epidemic, in which environmental factors must play a major part, not just aging,” he was quoted as saying.

Pritchard said no single factor was to blame, but instead blamed the interaction between different chemicals and varying types of pollution.

Other experts were more skeptical about the causes for the increase.

“We can’t conclude that modern life is causing these conditions at a younger age,” Dr. Simon Ridley, head of research at Alzheimer’s Research UK told the paper.

“We know that Alzheimer’s and other dementias can have a complex interplay of risk factors.”

“The rate of increase in such a short time suggested a silent or even a hidden epidemic, in which environmental factors must play a major part, not just aging.

COLIN PRITCHARD

BOURNEMOUTH UNIVERSITY