London - Modern life could be to blame for a “silent epidemic” of early dementia, British experts have warned.
People are commonly getting dementia ten years earlier than they were two decades ago, according to scientists.
The sharp increase may be due to car fumes and pesticides, they claim.
A team led by Bournemouth University compared health data from 21 Western countries recorded between 1989 and 2010.
They found that there was a trend of dementia starting at a much earlier age. Towards the end of the period people were commonly diagnosed in their late 40s compared with their early 60s two decades earlier.
Deaths caused by neurological disease also rose significantly in adults aged 55 to 74. For over-75s the rate doubled in every Western country in the same period.
Professor Colin Pritchard, who led the research, said environmental factors such as pollution from transport as well as widespread use of pesticides could be to blame.
The increase in death rates cannot simply be blamed on an ageing population or better diagnosis, he added.
Professor Pritchard, whose findings were published in the journal Surgical Neurology International, said: “The rate of increase in such a short time suggests a silent or even a hidden epidemic, in which environmental factors must play a major part, not just ageing.”
Results were partly explained by advances in medicine make physical illnesses easier to treat, meaning people die with neurological problems instead, he said.
But he added: “Crucially it is not just because people are living longer to get diseases they previously would not have lived long enough to develop but older people are developing neurological disease more than ever before. “
The environmental changes in the last 20 years have seen increases in the human environment of petro-chemicals – air transport, quadrupling of motor vehicles, insecticides and rises in background electro-magnetic field, and so on. In the UK, the death rate from dementia was 6 862 per million for men aged over 75, and 9 144 per million for women.
Other experts were sceptical that environmental factors were causing the increase.
Tom Dening, professor of dementia research at the University of Nottingham, said that falling death rates for cancer and heart disease would naturally mean other causes of death became more frequent, because “people have to die of something”.
Dr Simon Ridley, of Alzheimer’s Research UK, said the causes of Alzheimer’s and other dementias had a “complex interplay of risk factors”. He added: “We can’t conclude that modern life is causing these conditions at a younger age.”
Daily Mail