Are there natural antihistamines?

Natural Antihistamines: Evidence and Effectiveness

There are several natural substances with antihistamine properties, but pharmaceutical antihistamines remain the first-line treatment for allergic conditions due to their superior efficacy, standardized dosing, and established safety profiles.

Pharmaceutical vs. Natural Antihistamines

Pharmaceutical Antihistamines

Second-generation antihistamines are the preferred treatment for allergic conditions due to:

• Proven efficacy in relieving symptoms of allergic rhinitis and urticaria 1
• Less sedation compared to first-generation antihistamines 1
• Standardized dosing and well-established safety profiles 1
• Options include:
  • Fexofenadine, loratadine, and desloratadine (non-sedating at recommended doses)
  • Cetirizine (may cause some sedation at recommended doses) 1

Natural Antihistamines

Quercetin

• Most studied natural antihistamine
• Mechanism of action:
  • Inhibits histamine release from mast cells
  • Decreases pro-inflammatory cytokines
  • Suppresses interleukin IL-4 production
  • Improves Th1/Th2 balance
  • Inhibits IgE antibody formation 2
• Found in:
  • Onions
  • Broccoli
  • Apples
  • Berries
  • Grapes
  • Tea 2

Other Natural Substances with Antihistamine Properties

Research has identified several herbs with potential antihistamine effects:

• Piper longum
• Ocimum tenuiflorum (Holy basil)
• Solanum xanthocarpum
• Azadirachta indica (Neem)
• Aloe vera
• Tinospora cordifolia 3

Efficacy Comparison

Strength of Evidence

• Pharmaceutical antihistamines: Strong evidence from multiple clinical trials and guidelines 1, 4
• Natural antihistamines: Limited clinical evidence, mostly laboratory and animal studies 2, 5

Comparative Efficacy

• Quercetin has shown to be more competent in inhibiting IL-8 than cromolyn (an anti-allergic medication) in laboratory studies 2
• However, natural antihistamines lack standardized formulations and dosing guidelines

Clinical Applications

When to Consider Natural Antihistamines

• As complementary approaches to conventional treatment
• For mild allergic symptoms
• For patients concerned about medication side effects

When to Use Pharmaceutical Antihistamines

• For moderate to severe allergic rhinitis
• For urticaria and other allergic skin conditions
• When rapid symptom relief is needed 4

Safety Considerations

Natural Antihistamines

• Generally considered safe when consumed in food
• Supplement forms may have variable potency and purity
• Potential for herb-drug interactions
• Limited safety data in pregnancy and breastfeeding

Pharmaceutical Antihistamines

• Well-established safety profiles
• Second-generation antihistamines have minimal sedation
• First-generation antihistamines should be avoided due to sedation, performance impairment, and anticholinergic effects 6
• Caution in elderly patients due to increased fall risk 4

Treatment Algorithm

1. For mild allergic symptoms:

   • Try dietary sources of quercetin (onions, apples, berries)
   • Consider saline nasal irrigation for allergic rhinitis 1
   • Avoid known allergens and triggers 4

2. For moderate symptoms:

   • Second-generation antihistamines are recommended as first-line treatment 1, 4
   • Consider natural antihistamines as complementary approach

3. For severe symptoms:

   • Standard or increased doses of second-generation antihistamines 4
   • Consider specialist referral if symptoms persist

Conclusion

While natural antihistamines like quercetin show promise in laboratory studies, pharmaceutical antihistamines remain the evidence-based choice for treating allergic conditions. Natural approaches may be considered as complementary strategies but should not replace conventional treatment for moderate to severe allergic symptoms.