Herpes simplex virus linked to impaired memory

COLD sores may be linked to an increase in the risk of impaired memory and thinking skills, research suggests.

The herpes simplex virus that causes cold sores was one of a number of infections associated with reduced mental ability.

Scientists tested the thinking and memory of 1,625 people from New York city with an average age of 69.

Participants had their blood tested for five common low-grade infections: oral and genital herpes and the related ctomegalovirus, plus the respiratory form of chlamydia, and the stomach bug Helicobacter pylori. Those with higher levels of infection were 25 per cent more likely to deliver low score results in a standard mental function test.

The findings appear in the journal Neurology.