Snorers may think they face no greater problems than an occasionally angry spouse.

But if you snore, it could make it harder to remember past memories from your life.

People with obstructive sleep apnoea, a leading cause of snoring, have worse memories of years gone by.

They struggle to remember specific details, such as colleagues’ names or the house number and street they used to live in.

Every time someone with sleep apnoea snores, their throat is constricting to block their airway, which also cuts off oxygen to the brain.

Experts believe this may destroy grey matter in the part of the brain important for logging memories.

A study of 44 people with sleep apnoea, which affects 1.5million people in Britain and up to a third of pensioners, found they have much worse memories for life details from early adulthood.

Asked to recount their personal histories, more than half had an ‘over-general’ memory, where they struggled to remember specifics.

For healthy people of the same age, fewer than one in five had this problem, with most able to provide detailed memories.

Dr Melinda Jackson, who led the study from RMIT University in Australia, said: ‘Our study suggests sleep apnoea may impair the brain’s capacity to either encode or consolidate certain types of life memories, which makes it hard for people to recall details from the past.’

She added: ‘Brain scans of people with sleep apnoea show they have a significant loss of grey matter from regions that overlap with the autobiographic memory network.’

Researchers recruited people aged 20 to 69 with sleep apnoea, which causes snoring and interrupted sleep when the walls of the throat relax and prevent breathing.

They were asked to recall three memories each from their childhood, early adult life and recent life, which were judged on the level of detail people could provide. Their responses were compared to 44 people of the same age who did not have sleep apnoea.

When asked about their early adulthood, which could include a wedding, having children or starting out in their career, snoring seemed to affect memory.

The people with sleep apnoea were less able to recall details, such as addresses and names.

Researchers then gave people cue words, asking for memories which had made them feel guilty or proud, for example.

These were scored as ‘specific’ if they were focused, with exact times and places, or ‘overgeneral’ if the memory included many events or jumped about over a longer period of time.

This led the study to conclude that 52.3 per cent of people with sleep apnoea had a highly overgeneral memory, recalling five or more generalised memories. That compared to just 18.9 per cent of people free from the condition.

However the people with sleep apnoea did not show problems remembering episodes from their life. Details from recent times and childhood did not elude them either.

The sleep-deprived people may be worse at remembering early adulthood because that is when their snoring began to affect their brain. Or it may be that people with sleep apnoea struggle with memories from further back in the past.

Sleeping masks worn by people to open their airways have been found to help improve thinking problems, according to the study published in the Journal of the International Neuropsychological Society.

Dr Jackson said: ‘An important next step will be to determine whether successful treatment of sleep apnoea can also help counter some of these memory issues or even restore the memories that have been lost.’

Agencies