Drifting off to sleep while smelling lavender, eucalyptus or rosemary could help to boost your memory in later life.
Volunteers aged 60 to 85 who were exposed to fragrances at night for six months did far better in a memory test.
They improved their memory by 226 per cent compared to volunteers who did not get the same scent exposure.
The small study, of 43 people, suggests the act of smelling pleasant scents could stimulate the brain in a way which protects against memory loss.
The link between memory and sense of smell – known by scientists as the ‘olfactory’ sense – might help to explain why people in the early stages of dementia start to lose their ability to detect odours.
Professor Michael Yassa, a co-author of the scent study, from the University of California, Irvine, said: ‘The olfactory sense has the special privilege of being directly connected to the brain’s memory circuits.
(Stock Photo) Drifting off to sleep while smelling lavender, eucalyptus or rosemary could help to boost your memory in later life
‘All the other senses are routed first through the thalamus.
He said: ‘Everyone has experienced how powerful aromas are in evoking recollections, even from very long ago.
‘However, unlike with vision changes that we treat with glasses and hearing aids for hearing impairment, there has been no intervention for the loss of smell.’
The volunteers in the study were given a diffuser for their bedroom, and 20 out of 43 of them received essential oils, which smelled of lavender, rose, orange, eucalyptus, lemon, peppermint and rosemary.
They turned on the diffuser when they went to bed, and one scent per night was released into the air for two hours as they fell asleep.
The other 23 people, who were the control group, also switched on the diffuser when they went to bed, but their diffusers only pumped out distilled water with a minimal, undetectable scent.
The participants, who had no cognitive impairment or dementia, were given a battery of tests, including the Rey Auditory Verbal Learning Test, where people have to recall words from a list to gauge their verbal learning and memory.
The volunteers in the study were given a diffuser for their bedroom, and 20 out of 43 of them received essential oils, which smelled of lavender, rose, orange, eucalyptus, lemon, peppermint and rosemary
The 226 per cent better performance on this test was seen in the group exposed to the fragrances compared to the control group.
MRI scans revealed those who had fallen asleep with the seven scents over six months also had better functioning in the ‘uncinate fasciculus’ – a brain pathway which deteriorates with ageing and has been linked to memory.
The researchers of the study, published in the journal Frontiers in Neuroscience, say the finding transforms the long-known link between smell and memory into an easy technique for strengthening memory and potentially protecting against dementia.
It follows evidence that exposing people with moderate dementia to up to 40 different odours twice a day boosted their memories and language skills and eased depression.
Cynthia Woo, who led the new study from the University of California, Irvine, said: ‘By making it possible for people to experience the odours while sleeping, we eliminated the need to set aside time for this during waking hours every day.’