Spirulina for Allergies: Does It Really Work?

clinical-trial PMID: 32773785

Quick Summary: Research suggests spirulina, a type of blue-green algae, may be better than some allergy medicines at relieving symptoms like a runny nose and stuffiness. This study found spirulina also helped reduce inflammation linked to allergies.

What The Research Found

This study compared spirulina to cetirizine, a common allergy medicine. People taking spirulina had less:

Runny nose

Nasal congestion (stuffy nose)

Loss of smell

They also reported better sleep, work performance, and social activities. Plus, spirulina helped lower inflammation in the body.

Study Details

Who was studied: 53 people with allergic rhinitis (hay fever)

How long: 2 months

What they took: Spirulina (2 grams daily) or cetirizine (10mg daily)

What This Means For You

If you suffer from allergies and want a natural option, spirulina might help. It could be a good alternative if you experience side effects from allergy medicines, like drowsiness. Talk to your doctor before making any changes to your treatment plan.

Study Limitations

The study was small, so more research is needed.

It only lasted for two months, so we don't know the long-term effects.

The study didn't include a placebo (a "dummy" pill), so we can't be sure how much of the effect was due to the spirulina itself.

Key Findings

Spirulina (2 g/day) demonstrated superior efficacy to cetirizine (10 mg/day) in alleviating core allergic rhinitis (AR) symptoms and modulating inflammatory markers. After 2 months, the spirulina group showed significantly greater improvement in rhinorrhoea (P=0.021), nasal obstruction (P=0.039), and smell reduction (P=0.030) versus cetirizine. Sleep quality, daily work, and social activity also improved significantly with spirulina (P<0.05). Biomarker analysis revealed spirulina reduced pro-inflammatory interleukins IL-1α (P<0.001), IL-1β (P<0.001), and IL-4 (P=0.008) while increasing anti-inflammatory IL-10 (P<0.05) compared to cetirizine after 1 month.

Study Design

This was a randomized controlled clinical trial conducted at an accredited tertiary academic center. It enrolled 53 AR patients (23 men, 30 women; mean age 26.75 ± 9.26 years; range 8–58 years) randomized into spirulina (experimental) and cetirizine (control) groups. Baseline demographics and clinical presentations showed no significant intergroup differences (P>0.05). Symptom severity was assessed via standardized questionnaires, and inflammatory mediators (IL-1α, IL-1β, IL-4, IL-10) were measured before and after the 2-month intervention.

Dosage & Administration

The experimental group received Spirulina platensis at 2 grams per day orally. The control group received cetirizine 10 mg per day orally. Both interventions were administered daily for 2 months.

Results & Efficacy

Spirulina produced significantly greater reductions in key AR symptoms versus cetirizine: rhinorrhoea (P=0.021), nasal obstruction (P=0.039), and smell impairment (P=0.030). Functional outcomes (sleep, work, social activity) improved significantly with spirulina (P<0.05). Biomarker analysis showed spirulina induced a stronger anti-inflammatory shift: IL-1α and IL-1β decreased markedly (both P<0.001), IL-4 reduced (P=0.008), and IL-10 increased significantly versus cetirizine after 1 month (P<0.05 for all). No significant baseline differences in inflammatory mediators existed between groups.

Limitations

The study had a small sample size (n=53), limiting statistical power. Lack of a placebo group prevents distinguishing drug-specific effects from placebo responses. The 2-month duration is insufficient to assess long-term efficacy or safety. Demographic skew (61% female) and age range (8–58 years) may limit generalizability to specific subpopulations. Mechanisms behind IL-10 elevation with spirulina were not explored.

Clinical Relevance

For AR patients intolerant to antihistamines like cetirizine (e.g., due to drowsiness), spirulina at 2 g/day may offer a viable alternative with dual symptom relief and anti-inflammatory benefits. The significant improvement in daily functioning suggests meaningful quality-of-life impacts. However, this single study does not support replacing first-line antihistamines in standard care; it indicates potential for spirulina as an adjunct or alternative in specific cases. Users should consult healthcare providers before substituting prescribed treatments.