Can Astaxanthin Help Manage Asthma in POlluted Areas?

Investigating Astaxanthin as a Novel Therapy for Asthma Management in Polluted Environments

This study will test whether astaxanthin, a naturally occurring antioxidant supplement, can improve lung function, reduce airway inflammation, and improve asthma control in adults with mild-to-moderate asthma. Participants will receive astaxanthin and placebo in random order in a double-blind crossover design. Each treatment period lasts 4 weeks and is separated by a 3-week washout period. The study also measures indoor and personal air pollution exposure to examine whether pollution influences asthma symptoms, airway responsiveness, and response to treatment. Exploratory thoracic bioelectrical impedance spectroscopy will be assessed alongside standard respiratory tests.

Study Overview

• Status: Recruiting
• Conditions: Airway Inflammation; Airway Hyperresponsiveness; Asthma (Diagnosis)
• Intervention / Treatment: Dietary supplement: Astaxanthin Oral Capsule; Dietary supplement: Matched Placebo (Capsules)

Detailed Description

This is a randomized, double-blind, placebo-controlled, 2-sequence, 2-period crossover trial in 25 non-smoking, non-vaping adults aged 18 to 59 years with mild-to-moderate asthma or asthma-like symptoms confirmed at screening. Participants will be allocated 1:1 to one of two treatment sequences: astaxanthin followed by placebo, or placebo followed by astaxanthin. Each intervention period lasts 4 weeks and is separated by a 3-week washout. Astaxanthin will be given orally at a total dose of 12 mg/day as three 4 mg capsules taken with the participant's largest meal; placebo capsules will be matched. Outcome assessments include FeNO, spirometry, impulse oscillometry, body plethysmography, hypertonic saline challenge with induced sputum collection, home peak expiratory flow monitoring, questionnaires, and exploratory thoracic bioelectrical impedance spectroscopy. Indoor and personal air pollution exposures will be measured throughout the study to evaluate whether pollution modifies respiratory outcomes and treatment response.

• Study Type: Interventional
• Enrollment (Estimated): 25
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Ahmet Celen, PhD in Biomedical Science; Phone Number: +447840475597; Email: AC1534@live.mdx.ac.uk
• Study Contact Backup: Name: Dr Lygeri Dimitriou; Phone Number: +44 7813 356883

Study Locations

• United Kingdom
  • Barnet
    • London, Barnet, United Kingdom, NW4 4BT
      • Recruiting
      • Middlesex University

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Adults 18+ y

• Confirmed clinical diagnosis of mild-to-moderate asthma, defined as:

  • A physician diagnosed asthma condition consistent with BTS/NICE/SIGN (2024)
  • Asthma managed at GINA (2024) step 1-3 therapy level, with stable maintenance treatment for ≥4 weeks prior to enrolment
  • No asthma exacerbation requiring systemic corticosteroids within the preceding 6-8 weeks

(those with suspected Asthma will be invited to a familiarisation and eligibility session where they will have clinical investigations to assess for asthma and thus be included or excluded)

• Ability to demonstrate acceptable and repeatable spirometry in accordance with ATS/ERS standards
• Willing to refrain from antioxidant and anti-inflammatory supplementation (e.g. Omega-3, turmeric, NSAID supplements) for the duration of the study
• Not consuming high dietary ASTX sources (e.g., frequent salmonid or crustacean intake), assessed at screening
• non-smoking and non-vaping
• Able and willing to take daily study capsules and attend all required visits
• Able and willing to complete home monitoring, including peak flow, air-quality monitoring, and questionnaires
• Able to provide written informed consent

Exclusion Criteria:

• Current smokers or vapers which is associated with chronic airway remodelling, reduce hyperresponsiveness to bronchodilators, and increased neutrophilic inflammation, which can obscure the true effects of asthma-target interventions
• Respiratory tract infection within the preceding 4 weeks
• Pregnant or lactating individuals
• Presence of significant co-morbidities, including CVD or autoimmune or systemic inflammatory diseases
• Renal or gastrointestinal disorders that may affect astaxanthin absorption and metabolism
• Known allergy or hypersensitivity to ASTX or any components of the study supplement
• History of current evidence of alcohol or substance abuse
• Participation in another interventional drug or supplement study within the preceding 3 months
• Use of medicines with a narrow therapeutic index where supplement interactions may pose risk (e.g., ciclosporin/tacrolimus, warfarin), assessed by investigator
• Other significant chronic respiratory disease (e.g., COPD, bronchiectasis)

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Sequence A: Astaxanthin Then Placebo; Participants receive astaxanthin 12 mg/day orally for 4 weeks, followed by a 3-week washout, then matched placebo orally for 4 weeks.	Dietary supplement: Astaxanthin Oral Capsule; Natural astaxanthin derived primarily from Haematococcus pluvialis, administered orally as three 4 mg capsules daily (total 12 mg/day) with the participant's largest meal for 4; Dietary supplement: Matched Placebo (Capsules); Matched placebo capsules administered orally once daily as three capsules with the participant's largest meal for 4 weeks.
Experimental: Sequence B: Placebo Then Astaxanthin; Participants receive matched placebo orally for 4 weeks, followed by a 3-week washout, then astaxanthin 12 mg/day orally for 4 weeks.	Dietary supplement: Astaxanthin Oral Capsule; Natural astaxanthin derived primarily from Haematococcus pluvialis, administered orally as three 4 mg capsules daily (total 12 mg/day) with the participant's largest meal for 4; Dietary supplement: Matched Placebo (Capsules); Matched placebo capsules administered orally once daily as three capsules with the participant's largest meal for 4 weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Forced Expiratory Volume in 1 Second (FEV1)	FEV1 measured by spirometry using a calibrated Medisoft BodyBox system. Comparison is within-participant change after astaxanthin versus placebo.	Measured at period-specific baseline and restablishment of baseline after washout period and end of each 4-week treatment period
Change in Fractional Exhaled Nitric Oxide (FeNO)	FeNO measured in parts per billion using the NIOX VERO analyser. Comparison is within-participant change after astaxanthin versus placebo.	Measured at period-specific baseline and restablishment of baseline after washout period and end of each 4-week treatment period
Change in Airway Hyperresponsiveness During Hypertonic Saline Challenge	Hypertonic saline challenge response quantified using the dose response slope	Measured at period-specific baseline and end of each 4-week treatment period

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Impulse Oscillometry Resistance at 5 Hz (R5)	R5 measured during tidal breathing using the PulmoScan system	Baseline, end of phase 1, post washout and end of phase 2
Change in Impulse Oscillometry Area of Reactance (AX)	AX measured using the PulmoScan system as an index of peripheral airway involvement.	Baseline, end of phase 1, post washout and end of phase 2
Change in Asthma Control Questionnaire-6 (ACQ-6) Total Score	Participant-reported asthma control measured using the ACQ-6.	Weekly during the 11- to 12-week study period
Change in Asthma Quality of Life Questionnaire (AQLQ) Total Score	Every 2 weeks during the 11- to 12-week study period	Participant-reported asthma-related quality of life measured using the AQLQ.
Change in Peak Expiratory Flow Amplitude Percent Mean (PEF APM)	Diurnal variability in peak expiratory flow derived from home morning and evening PEF	Twice daily during each treatment period and washout, up to 11 to 12 weeks
Change in Sputum Eosinophil Percentage	Baseline, end of phase 1, post washout period and end of phase 2	Induced sputum cellular differential measured after hypertonic saline challenge.
Change in Sputum Interleukin-8 (IL-8) Concentration	Baseline, end of phase 1, post washout and end of phase 2	IL-8 measured in processed induced sputum.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Thoracic Bioelectrical Impedance Spectroscopy Phase Angle	Exploratory TBIS measure obtained using the BodyStat Multiscan 500 to assess feasibility and physiological coherence relative to standard respiratory measures	Baseline, end of phase 1, post washout and end of phase 2. And supplementary changes during hypertonic saline challenge testing

Collaborators and Investigators

• Sponsor: Middlesex University
• Collaborators: AstaReal; BodyStat Ltd.; British Pest Control Association
• Investigators: Study Director: Lygeri Dimitriou, Middlesex University

Study record dates

Study Major Dates

• Study Start (Estimated): May 15, 2026
• Primary Completion (Estimated): July 20, 2026
• Study Completion (Estimated): July 20, 2026

Study Registration Dates

• First Submitted: March 27, 2026
• First Submitted That Met QC Criteria: March 27, 2026
• First Posted (Actual): April 2, 2026

Study Record Updates

• Last Update Posted (Actual): April 2, 2026
• Last Update Submitted That Met QC Criteria: March 27, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Air Pollution; Astaxanthin; FeNO; Impulse Oscillometry; Mild-to-Moderate Asthma; Hypertonic Saline Challenge; Thoracic Bioelectrical Impedance Spectroscopy
• Additional Relevant MeSH Terms: Pathologic Processes; Immune System Diseases; Respiratory Tract Diseases; Lung Diseases; Bronchial Diseases; Lung Diseases, Obstructive; Hypersensitivity, Immediate; Hypersensitivity; Pathological Conditions, Signs and Symptoms; Asthma; Disease; Respiratory Hypersensitivity; Pharmaceutical Preparations; Dosage Forms; Capsules; astaxanthine
• Other Study ID Numbers: Ethics application ETH2425-008

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

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