Reviewed: Pachikian BD, Copine S, Suchareau M, Deldicque L. Effects of saffron extract on sleep quality: A randomized, double-blind controlled clinical trial. Nutrients. April 2021;13(5):1473. doi: 10.3390/nu13051473.
Insomnia and sleep disorders are significant health concerns that can result in fatigue, attention deficits, mood instability, anxiety, and depression. Insomnia is associated with reductions in hippocampal volume (the hippocampus is an area of the brain important for learning and memory function), daytime cortical gamma-aminobutyric acid (GABA) levels, and blood oxygen level-dependent (BOLD) signals* of the caudate nucleus (which is involved in executive functioning). Each of these effects can cause a constant state of hyperarousal and overactivity of emotion-regulating and cognitive systems, which can lead to insomnia.
Medications exist to treat the symptoms of insomnia. However, patients can develop tolerance and dependence, resulting in increased morbidity and mortality with long-term use. Therefore, other therapeutic options are needed. Saffron (Crocus sativus, Iridaceae) stigmas contain safranal, crocin, and crocetin — compounds examined for their effects on depression and anxiety in humans. Research into saffron’s effects on sleep duration and quality also has been conducted. However, studies have shown mixed results. The authors conducted a randomized, double-blind, placebo-controlled parallel study to evaluate the effects of saffron on sleep quality using questionnaires and actimeters (devices that measure movement and rest).
The study was conducted at the Center of Investigation in Clinical Nutrition in Louvain-La-Neuve, Belgium, between August 2019 and October 2020. Participants were recruited through posters, mailings, social networks, and local newspapers. Men and women between 25 and 70 years of age who had a mild to moderate chronic primary sleep disorder (Insomnia Severity Index scores between 7 and 21) and mild to moderate anxiety (Perceived Stress Scale scores between 6 and 29) were included. Women were required to use contraception during the study. Participants were excluded if they had sleep disorders connected to pre-existing health issues, were resistant to common hypnotic drugs, had abnormal blood samples, were diagnosed with or had a history of addiction, or consumed more than three servings of alcohol, 500 mL of tea (Camellia sinensis, Theaceae), 400 mL of coffee (Coffea spp., Rubiaceae), or 250 mL of energy drinks daily. Individuals who were pregnant or lactating, had lifestyle habits that disrupted the wake-sleep rhythm, had an allergy to saffron or olives (Olea europaea, Oleaceae), or had a gastrointestinal, hepatic, respiratory, psychiatric, kidney, or cardiovascular disorder within three months of inclusion also were excluded.
Participants were randomly assigned to either the placebo or saffron group and ingested one capsule each evening with a glass of water for six weeks. The saffron group received 15.5 mg of saffron extract containing 0.9 mg of crocins and 0.7 mg of safranal (Saffr’Activ® SAF 3C PIM; Comercial Química Massó; Barcelona, Spain) and 259.5 mg maltodextrin. Of note, the study used an experimental saffron extract with a different composition than Massó’s commercial product. The placebo capsules contained 275 mg maltodextrin. Both placebo and saffron were packaged in identical chlorophyll capsules.
At baseline, week 3, and week 6, actigraphy was used to measure sleep efficiency (SE, the ratio of total time spent asleep to the total time spent trying to sleep), sleep onset latency (SOL, the length of time it takes to transition from full wakefulness to sleep), time in bed (TIB), fragmentation index (FRAGI, which detects sleep fragmentation or disruption), total sleep time (TST), and wake after sleep onset (WASO, periods of wakefulness after sleep onset). Actigraphy is a non-invasive method that assesses sleep-wake cycles over long periods of time in the participant’s own bed using a motion-sensitive watch-like device called an actimeter or actigraph (MotionWatch 8; CamNtech Ltd.; Cambridgeshire, United Kingdom).
The Leeds Sleep Evaluation Questionnaire (LSEQ), Pittsburgh Sleep Quality Index (PSQI), and 36-item Short Form Health Survey (SF-36) questionnaires were used to assess perceived sleep quality and well-being. Food diaries were completed at baseline and at the end of the intervention.
Of the 98 individuals who were screened, 66 were selected to participate, 62 completed the study, and 59 were included in the final analysis. In the placebo group, one person was dropped from the study due to the use of a sleeping drug, and one individual was excluded due to lack of actimeter data, leaving 30 participants in the data analysis. In the saffron group, one person was dropped due to an adverse event (heart palpitations after ingestion), and four people were dropped for use of sleep medication or lack of compliance, leaving 29 participants in the final analysis.
There were no changes in total dietary energy (calories), protein, alcohol, tea, or soda intake between weeks 0 and 6 in either group. However, there was an increase in carbohydrate consumption in both groups and an increase in coffee intake in the saffron group. The mean age was 44 ± 15 in the placebo group and 46 ± 13 in the saffron group. There was no significant difference in the placebo group for the actimeter data between week 0 and week 6, while there was an increase in TIB (P = 0.051) in the saffron group. There was no difference seen in SE, SOL, FRAGI, TST, or WASO.
Quality of sleep, ease of awakening from sleep, and alertness and behavior after wakefulness increased for both groups after three and six weeks, compared to baseline (P < 0.05), but no statistical difference was found between groups. There was an increase in “ease of getting to sleep” in the saffron group between baseline and week 6 (P = 0.041), but no significant difference was observed in the placebo group.
The saffron group had significantly lower (i.e., improved) sleep quality (P = 0.014), sleep latency (P = 0.032), and sleep duration (P = 0.013) PSQI scores at week 6 compared to baseline. Lower scores for sleep quality and latency also were observed in the placebo group, but the results were not statistically significant. After six weeks, both placebo and saffron groups had a decrease in daytime dysfunction from baseline (P < 0.001 for both). Compared to baseline, a decrease in global PSQI score was seen in only the saffron supplementation group (P = 0.001).
The saffron group’s global physical score (P = 0.041), bodily pain score (P = 0.035), physical functioning score (P = 0.055), and general health score (P = 0.053) improved after six weeks. There was no significant change in the placebo group. Both groups saw an improvement between baseline and week 6 in vitality, mental health, and global mentality scores (P < 0.05 for all). The placebo group saw an improvement compared to baseline for the social functioning score (P = 0.002), but there was no significant change in the saffron group. The saffron group saw improvement of the emotional limitation score compared to baseline (P = 0.005), but the placebo group saw no change.
The authors concluded that saffron extract supplementation led to an improvement in sleep quality after six weeks. The results agree with a previous study performed by Lopresti et al (2020),1 which reported an improvement of insomnia symptoms (measured by the Insomnia Severity Index score) after seven days of supplementation, with an extract having similar crocins and safranal concentrations as the experimental product tested in the current study. Since the study included only individuals with mild to moderate chronic primary sleep disorder with a specific dosage of saffron, the authors noted that it would be beneficial to perform more studies using different dosages of saffron to better understand its mechanism and to recruit participants with more severe chronic primary sleep disorders.
* Reduced BOLD signals are commonly interpreted as reductions in neuronal activity.
- Lopresti AL, Smith SJ, Metse AP, Drummond PD. Effects of saffron on sleep quality in healthy adults with self-reported poor sleep: A randomized, double-blind, placebo-controlled trial. J Clin Sleep Med. 2020;16(6):937-947. doi: 10.5664/jcsm.8376.