Cleanliness is next to Alzheimer’s?
|Published
Better sanitation and urban living were linked with a higher incidence of the disease, irrespective of life expectancy. Better sanitation and urban living were linked with a higher incidence of the disease, irrespective of life expectancy.
London - An obsession with being too clean and hygienic could lead to a higher risk of dementia, researchers have warned.
Their study pinpointed a significant relationship between a nation’s cleanliness and the number of Alzheimer’s patients.
Countries which can afford better sanitation have higher rates of the disease. So Britons and inhabitants of other developed nations were around ten per cent more likely to suffer dementia than those in countries like Kenya and Cambodia.
The researchers suggested the “hygiene hypothesis” was behind the difference. This is the theory that an excessively clean lifestyle leaves our immune systems out of balance and unable to combat many germs.
It has already been linked to the rise in the number of allergies, such as asthma and eczema.
One in three Britons over 65 will develop dementia. Alzheimer’s and other forms of the condition blight the lives of more than 800 000, with 500 new cases each day.
Lead researcher Dr Molly Fox, from Cambridge University, said: “The hygiene hypothesis is well-established. We can now add Alzheimer’s to this list of diseases.
“There are important implications, especially in developing countries as they increase in sanitation.”
The study of health data from 192 nations found those with a relatively low risk of infection had more patients with Alzheimer’s.
Likewise, better sanitation and urban living were linked with a higher incidence of the disease, irrespective of life expectancy. Taken together, these factors accounted for 42.5 percent of the variation in rates of Alzheimer’s between countries.
Dr Fox said changes in diet, life expectancy and healthcare could not explain the differences.
The researchers found that exposure to germs throughout an individual’s lifetime, not just early on, may affect the risk of dementia.
A lack of contact upsets the development of white blood cells, particularly those called T-cells, which are a key part of the immune system.
This imbalance has been linked to the types of inflammation found in the brains of those with Alzheimer’s, said the report in the journal Evolution, Medicine and Public Health.
Dr Fox added: “We need to find the right balance of exposure.”
A spokesman for the Alzheimer’s Society said: “It is an interesting theory. However, it is always difficult to pin causality to one factor.”
The best way to cut risk is to eat healthily, exercise, not smoke and keep blood pressure and cholesterol in check, he added. - Daily Mail