Chronic infection in early life could 'leave brain vulnerable to Alzheimer's'
Brain inflammation could be an early event in development of degenerative disease, say experts
09:48 GMT, 2 July 2012
There are currently 800000 people with dementia in the UK. It causes memory loss and mood swings as it progresses
Suffering a brain infection early in life could increase the risk of developing Alzheimer's disease, research suggests.
Scientists from the University of Zurich made the connection after triggering brain inflammation in unborn mice.
They found just a single infection during late pregnancy was enough to induce long-term neurological changes and memory problems in old age.
The mice had boosted levels of immune system signalling molecules linked to inflammation.
The effect was even stronger if the mice were infected in adulthood. This resulted in changes similar to those seen in Alzheimer's patients.
Mice genetically modified to produce a human version of the Alzheimer's-associated brain protein amyloid-beta showed the most striking reaction.
'It seems likely that chronic inflammation due to infection could be an early event in the development of Alzheimer's disease,' said study leader Dr Irene Knuesel, from the University of Zurich in Switzerland.
The research is published in the Journal of Neuroinflammation.
If the findings can be shown to apply to humans, it would suggest a role for anti-inflammatory drugs in treating Alzheimer's.
Dr Marie Janson, from the charity Alzheimer's Research UK, said: 'The results of this study suggest that repeated or severe infections may contribute to the development of Alzheimer's disease in mice. '
Alzheimer's disease in humans: These CT scans of a 74-year-old dementia patient shows signs of brain shrinkage in the enlarged cavities (white areas) and pale blue outer region
However, she added: 'While we know that the immune system plays a role in human Alzheimer's disease, clinical trials with anti-inflammatory drugs have not yet shown conclusive benefits in treating the disease and so more research is needed to fit these pieces of the puzzle together.
'Understanding the risk factors for Alzheimer's disease is essential, especially if some of these factors are things that we can actively change or avoid. This understanding can only come through research, yet research into dementia remains hugely underfunded.'
Dementia affects 820,000 people in the UK and 25 million of the UK population have a close friend or family member with the condition. As the population ages the number of sufferers is expected to soar by to 1.7million by 2050.
According to Alzheimer's UK the disease costs the UK economy 23 billion a year, more than cancer and heart disease combined.