Taking lemon balm can boost memory as well as improve mood, researchers have found.
Lemon balm 'improves mood'
The benefits of lemon balm, a common weed that resembles a small nettle, has long been recognised. In the 16th century, herbalist John Gerard gave it to students to "quicken the senses".
Tests have now shown it helps people learn, store and retrieve information.
Laboratory tests found lemon balm increased the activity of acetylcholene, a chemical messenger linked to memory that is reduced in people with Alzheimer's disease.
It may help conditions where the memory is fragile
Dr Andrew Scholey, Northumbria University
Dr Andrew Scholey and Dr David Kennedy, from Northumbria University, made capsules of dried lemon balm grown locally and gave them to a group of 20
They then carried out memory tests one, three and six hours later.
There was no effect on working memory - the constant
recall of continual events during the day.
But secondary memory, the ability to learn, store and retrieve information, was improved.
The findings were presented to presented to the British Psychological Society's annual conference in Bournemouth.
Dr Scholey said it was too early to say whether lemon balm might help Alzheimer's sufferers, but said: "It may help conditions where the memory is fragile."