Melissa officinalis, known as lemon balm, is a lemon-scented herb used for centuries for medicinal purposes. More recently, research has focussed on lemon balm’s bioactive properties, including its central nervous system effects.
Lead researcher and Director of the Centre for Human Psychopharmacology, Professor Andrew Scholey, previously worked on a pilot study that demonstrated potential anti-stress effects of lemon balm, and was keen to investigate further.
“Following the pilot study, we conducted two double-blinded, placebo-controlled crossover studies, evaluating the mood and cognitive effects of lemon balm extract, given in the form of a beverage as well as a yoghurt drink,” said Professor Scholey.
In each study, a cohort of healthy young adults was asked to rate their mood before and after a multi-tasking framework that was administered one and three hours following the lemon balm treatment.
Participants, who consumed the lemon balm in the form of a drink, received an identical 480ml serving containing either 0.3g lemon balm, 0.6g lemon balm or a placebo beverage.
Participants who consumed the yoghurt treatment received an identical 250g tub of yoghurt, containing the same quantities of lemon balm as the first beverage study. A placebo of yoghurt without lemon balm was also given.
“The pattern of results depended on the dose and the type of food the lemon balm was in. The most striking finding was that 0.3 g lemon balm beverage decreased the anxiety caused by multi-tasking and also decreased levels of the stress hormone cortisol. There were also improvements to working memory,” said Professor Scholey.
“The same dose was associated with increased alertness when delivered in yoghurt.”
“These results are extremely promising as it’s important that bioactive nutrients can be delivered in ways which are palatable for consumers, especially if they are going to be used in clinical populations.”
“However we should treat them with some caution as there were cognitive ‘costs’ associated with other doses of lemon balm,” Professor Scholey warned.