Ginger extract versus Loratadine in the treatment of allergic rhinitis: a randomized controlled trial.

The short version

This randomized, double-blind, controlled trial with 80 adults (ages 18-70, about 70% female) compared ginger (Zingiber officinale) extract against loratadine, a standard non-drowsy antihistamine, for allergic rhinitis (AR) -- an immune reaction to airborne allergens that causes nasal itching, congestion, runny nose, and sneezing, affecting an estimated 400 million people worldwide. Ginger is a spice long used in Thai traditional medicine, and its active compounds 6-gingerol and 6-shogaol have shown anti-allergic activity in lab studies by blocking mast cells, the immune cells that release histamine during an allergic reaction. Antihistamines like loratadine work well but can cause drowsiness and dry mouth. Participants with moderate AR symptoms took either 500 mg of standardized ginger extract or 10 mg of loratadine daily, in identical-looking capsules, for 6 weeks. Researchers tracked nasal symptoms using the Total Nasal Symptom Score (TNSS, rating itching, runny nose, congestion, and sneezing on a 0-12 scale), objectively measured nasal airway size with acoustic rhinometry (a sound-wave-based nasal scan), and assessed quality of life with the 28-item Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ). Blood tests and blood pressure checks monitored safety at baseline, week 3, and week 6. Both treatments significantly reduced nasal symptom scores by week 6 (ginger: 7.48 to 3.42; loratadine: 7.38 to 4.11), with no statistically significant difference between them (p=0.276--meaning both worked about equally well). On the nasal airway scan, ginger significantly increased left-nostril airway volume compared to loratadine by week 6 (+0.094 cm3 vs -0.006 cm3, p=0.02--meaning ginger measurably relieved congestion where loratadine did not). Quality-of-life scores improved similarly in both groups across all seven RQLQ domains (p=0.660 at week 6). Side effects differed in kind more than in severity: ginger caused more digestive upset (eructation, or burping, in 72% vs 17% on loratadine), while loratadine caused more drowsiness (25% vs 3%), dizziness, and constipation. Neither treatment affected blood pressure or kidney function; loratadine modestly raised a liver enzyme (ALP) that ginger did not. These results suggest ginger extract works about as well as loratadine for relieving AR symptoms and improving quality of life, with a milder side-effect profile centered on digestion rather than sedation. The trial was short (6 weeks), single-site, and modestly sized (80 enrolled, 72 completing), so larger and longer studies are needed to confirm both the congestion benefit and long-term safety, including the loratadine-associated liver-enzyme signal seen here.

Key findings

• A daily 500 mg dose of ginger (Zingiber officinale) extract relieved allergic rhinitis symptoms (nasal congestion, itching, sneezing, and runny nose) about as effectively as the antihistamine loratadine over 6 weeks, based on a validated 0-12 symptom scale called the Total Nasal Symptom Score (TNSS).
• A sound-wave nasal scan called acoustic rhinometry, which measures the size and shape of the nasal airway, showed that ginger extract opened up nasal passages significantly more than loratadine did by week 6.
• Ginger extract caused more mild digestive side effects such as burping (eructation, in 72% of participants) but far less drowsiness (under 3% versus 25% with loratadine), a trade-off the authors highlight for situations where alertness matters.
• Blood pressure, kidney function, and liver function tests showed that ginger extract was as safe as loratadine over the 6-week trial period.
• Because this trial included only 80 adults at one hospital in Thailand over a short period, larger and longer studies are needed before ginger extract can be recommended as a standard allergic rhinitis treatment.

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