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. 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, [said]. 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. 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 to74, virtually doubling in the over-75s. 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."