‘Scent’ may reduce stress, improve sleep, study reveals

HOLY basil, in low doses, can reduce stress and insomnia and increase sleep efficiency, according to the results of a recent trial, published in the journal, Nutrition.

Adult participants recorded 37% reductions in perceived stress, 48% decreased insomnia, and 3.4% increased sleep efficiency after taking 250mg daily for eight weeks.

Holy basil, common called efirin or scent leaf, is believed to promote longevity and general well-being but clinical trials also testify to its anti-stress, adaptogenic, antioxidant and analgesic properties, among others.

There are limited trials on Ocimum as an anxiolytic agent, although anti-stress benefits have been identified in adults with stress and anxiety disorders when consumed in doses of 1,000 and 1,200mg, respectively.

However, the current trial observed anti-stress effects of holy basil at a much lower dose (250mg) and also demonstrated sleep-enhancing benefits not previously studied, the authors wrote in the journal.

Participants aged 18 to 65 years were recruited for the double-blind, placebo-controlled trial through social media advertising and email databases and were required to score 14 or higher on the perceived stress scale (PSS) and give a rating of three or higher on at least one of the first five questions of the immune stress questionnaire (ISQ), as part of inclusion criteria.

The intervention extract (Holixer) was supplied by Natural Remedies in India and contained 62.5mg of Ocimum tenuiflorum per capsule. The placebo contained microcrystalline cellulose and syloid. Both products matched in appearance for colour, shape, size, smell, and taste.

Volunteers were instructed to take two capsules twice daily with or without food for eight weeks.

The primary outcome on stress levels and secondary outcome on mood state were measured using a range of self-reported questionnaires, data from a Fitbit to measure sleep time and efficiency, and hair cortisol analyses.

Findings indicate that holy basil has the potential to reduce HPA-axis activity after exposure to an acute stressor and demonstrated by overall reductions in cortisol, salivary alpha-amylase (sAA), blood pressure and stress ratings before and up to 40 minutes following exposure to the MAST.

There were significantly lower hair cortisol concentrations in subjects in the intervention group compared to the placebo, the authors noted.

They explained that reductions in salivary sAA and cortisol suggest that Ocimum had a buffering effect on the SAM system and the HPA axis, respectively, in response to an acute stressor.

Results showed that between-group changes in sleep efficiency and total sleep time measured by the Fitbit were not significantly different and there were no changes in other self-reported mood measures.

Despite several positive findings, the authors pointed out several limitations and proposed directions for future research.

The protocol for measuring hair cortisol was oversimplified and should involve collection of hair samples at baseline and end of treatment to ensure a more reliable measure of change in cortisol in future, the authors said.

They also pointed out that future research should establish product efficacy at various doses and treatment periods, as well as focusing on benefits based on age, sex and various environmental and social stressors, and on individuals with diagnosed anxiety disorders.