Older people’s memory loss linked to past viral illnesses

Forgetfulness is often seen as a symptom of getting older. But memory problems in advancing years could in fact be down to a common virus contracted decades before, scientists claim.

New research has found that exposure to strains of the herpes viruses and a common parasite could affect memory and thinking in older adults, years after first exposure.

The five-year study involving 1,000 over-65s found that infected adults were more likely to suffer from cognitive decline, usually attributed to getting older, such as memory loss and confusion, than those who were infection-free.

‘We targeted viruses that infect you at different times of your life and then stick around in your body for ever – they don’t leave you,’ says Dr Vishwajit Nimgaonkar, lead investigator in the research at the University of Pittsburgh School of Medicine in Pennsylvania.

‘Our belief is that these are the ones that are more likely to be causing you mischief.’

Although the exact reason why these infections contribute to cognitive decline has yet to be determined, it is thought that over longer periods the infections overload the immune system. As parts of the immune system play specialised roles in brain tissue, an overload may contribute to declining mental abilities.

‘We are not claiming these infections are the only thing playing a role, we are just building up the evidence,’ Dr Nimgaonkar adds.

‘If we can show that these agents cause cognitive decline, that’s potentially an argument for developing vaccinations.’

The study focused on patients exposed to the herpes