Saffron Extract Supplementation and Sleep Quality in Middle-Aged Adults (SAFFRON-SLEEP)

Effects of Daily Saffron Extract Supplementation on Sleep Quality in Middle-Aged Adults: A Randomized, Triple-Blind, Placebo-Controlled Clinical Trial

This randomized, triple-blind, placebo-controlled clinical trial aims to evaluate the effects of daily saffron extract supplementation (30 mg/day) for six weeks on objective and subjective sleep quality in middle-aged adults with mild-to-moderate sleep disturbances. Secondary outcomes include heart rate variability, cognitive processing speed, emotional state, perceived health status, and biochemical stress markers.

Study Overview

• Status: Recruiting
• Conditions: Sleep
• Intervention / Treatment: Dietary supplement: Saffron Extract; Dietary supplement: Dietary Supplement: Placebo

Detailed Description

Sleep disturbances are highly prevalent in middle-aged adults and are associated with impaired daytime functioning, increased cardiometabolic risk, and reduced quality of life. Pharmacological treatments may be effective but are often associated with adverse effects and dependency risk.

Saffron (Crocus sativus L.) contains bioactive compounds such as crocins and safranal, which may modulate neurotransmitter systems involved in sleep regulation, including serotonin, dopamine, and GABA pathways.

Eighty middle-aged adults with mild-to-moderate sleep disturbances will be randomly assigned to receive either 30 mg/day of standardized saffron extract or placebo for six weeks. Sleep will be objectively assessed using wrist-worn accelerometry over 14 days before and during the final weeks of intervention. Subjective sleep quality will be evaluated using validated questionnaires.

The study follows CONSORT guidelines and will be conducted in accordance with the Declaration of Helsinki and Good Clinical Practice standards.

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Lucas Jurado-Fasoli, PhD; Phone Number: +34618375662; Email: juradofasoli@ugr.es

Study Locations

• Spain
  • Granada
    • Granada, Granada, Spain, 18016
      • Recruiting
      • Universidad de Granada
      • Contact: Lucas Jurado Fasoli; Phone Number: +34618375662; Email: juradofasoli@ugr.es

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age 18-65 years
• Mild-to-moderate sleep disturbances
• BMI between 18 and 35 kg/m²
• Not receiving active pharmacological or psychological treatment for sleep disorders
• Willingness to comply with study procedures

Exclusion Criteria:

• Severe neurological, psychiatric, or cardiovascular disorders
• Diagnosed with obstructive sleep apnea, treated with CPAP
• Night shift workers
• Use of medications or supplements affecting sleep
• Recreational drug use
• Pregnancy or breastfeeding
• Uncontrolled medical conditions

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Saffron Extract; Dietary Supplement: Saffron extract Participants will receive 30 mg/day of standardized saffron extract (≥3% crocins; ≥2% safranal) for six weeks. Capsules will be taken once daily, one hour before bedtime.	Dietary supplement: Saffron Extract; Participants will receive 30 mg/day of standardized saffron extract (≥3% crocins; ≥2% safranal) for six weeks. Capsules will be taken once daily, one hour before bedtime.
Placebo Comparator: Placebo; Dietary Supplement: Placebo Participants will receive identical capsules containing maltodextrin and excipients for six weeks, taken once daily one hour before bedtime.	Dietary supplement: Dietary Supplement: Placebo; Participants will receive identical capsules containing maltodextrin and excipients for six weeks, taken once daily one hour before bedtime.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Objective Sleep Efficiency (%)	Measured by wrist actigraphy over 14 consecutive days before intervention and during weeks 5-7 of supplementation.	Baseline and Week 6

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total Sleep Time (hours)	Objectively measured total sleep time (in hours) assessed using wrist-worn triaxial accelerometry over 14 consecutive days. Data will be processed using validated algorithms integrating movement patterns and sleep diaries.	Baseline and Week 6
Wake After Sleep Onset (minutes)	Wake After Sleep Onset (WASO), defined as the total number of minutes awake after initial sleep onset, measured objectively by wrist actigraphy over 14 consecutive days.	Baseline and Week 6
Sleep Latency (minutes)	Sleep latency, defined as the time (in minutes) from reported bedtime to sleep onset, measured objectively using wrist-worn accelerometry and participant sleep logs.	Baseline and Week 6
Pittsburgh Sleep Quality Index (PSQI) Score	Subjective sleep quality assessed using the Pittsburgh Sleep Quality Index (PSQI), a validated questionnaire that evaluates sleep quality over the previous month. Total score ranges from 0 to 21, with higher scores indicating poorer sleep quality.	Baseline, Week 4, and Week 6
Insomnia Severity Index (ISI) Score	Severity of insomnia symptoms assessed using the Insomnia Severity Index (ISI). Total score ranges from 0 to 28, with higher scores indicating greater insomnia severity.	Baseline, Week 4, and Week 6
Epworth Sleepiness Scale (ESS) Score	Daytime sleepiness assessed using the Epworth Sleepiness Scale (ESS). Total score ranges from 0 to 24, with higher scores indicating greater daytime sleepiness.	Baseline, Week 4, and Week 6
Heart Rate Variability (RMSSD and SDNN)	Cardiac autonomic modulation assessed through heart rate variability (HRV) analysis under resting conditions. Time-domain parameters include RMSSD (root mean square of successive differences) and SDNN (standard deviation of normal-to-normal intervals), measured during a 5-minute stable segment.	Baseline and Week 6
Emotional State (BDI-FS, STAI, PSS-10 Scores)	Emotional status assessed using validated psychometric instruments: Beck Depression Inventory-Fast Screen (BDI-FS) State-Trait Anxiety Inventory (STAI) Perceived Stress Scale (PSS-10) Higher scores indicate greater depressive symptoms, anxiety, and perceived stress, respectively.	Baseline, Week 4, and Week 6
Health-Related Quality of Life (SF-36 Score)	Health-related quality of life assessed using the Short Form-36 Health Survey (SF-36), which evaluates physical and mental health domains. Scores are standardized from 0 to 100, with higher scores indicating better perceived health status.	Baseline, Week 4, and Week 6
Biochemical Stress Markers (Cortisol, ACTH, Glucose, Insulin)	Biochemical markers related to stress and metabolic function, including serum cortisol, adrenocorticotropic hormone (ACTH), fasting glucose, and insulin levels, obtained from clinical records and laboratory analyses.	Baseline and Week 6

Collaborators and Investigators

• Sponsor: Universidad de Granada

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): June 1, 2027

Study Registration Dates

• First Submitted: March 23, 2026
• First Submitted That Met QC Criteria: March 23, 2026
• First Posted (Actual): March 27, 2026

Study Record Updates

• Last Update Posted (Actual): April 13, 2026
• Last Update Submitted That Met QC Criteria: April 7, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Randomized clinical trial; Insomnia; Sleep quality; Nutraceutical; Actigraphy; Saffron extract
• Additional Relevant MeSH Terms: Nervous System Diseases; Mental Disorders; Sleep Wake Disorders; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Initiation and Maintenance Disorders
• Other Study ID Numbers: SAFFRON-SLEEP-UGR-2025

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: De-identified individual participant data may be shared upon reasonable request and after approval by the principal investigator, in accordance with institutional and GDPR regulations.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No