Researchers: Cinnamon and Allergic Reactivity

Ricercatori: la cannella e la reattività allergica

Updated and contextualized version of an article originally published on June 12, 2014
The article retains its original focus by presenting it through a scholarly and accessible perspective, supported by verifiable references.

Authors

  • Dr. A. Colonnese – Nutrition biologist
  • Roberto Panzironi –Independent researcher 

Note editoriali

  • First publication: June 12, 2014
  • Last update: April 18, 2026
  • Version: 2026 narrative revision  

IN BRIEF

  • Experimental studies show that cinnamon extracts and its main component, cinnamaldehyde, can reduce mast cell degranulation, a key step in allergic reactions.
  • A small controlled clinical trial reported improvement in allergic rhinitis symptoms using a standardized cinnamon extract nasal spray (IND02).
  • Evidence includes in vitro data, animal studies, and some clinical trials; the strength of the evidence varies depending on the model and the form of extract or compound used.
  • Practical application is cautious: promising results but they do not replace established medical therapies; doses, formulations, and long-term safety require more research.

Abstract: what does science say?

Cinnamon (Cinnamomum spp.) contains biologically active compounds — particularly type A proanthocyanidins and cinnamaldehyde — which show anti-inflammatory activity and modulation of immune cells involved in allergies. In vitro and animal model experiments have shown a reduction in mast cell degranulation and a decrease in some pro-inflammatory mediators. A randomized clinical trial on a standardized nasal spray reported a reduction in allergic rhinitis symptoms after seven days of treatment. However, the evidence is not homogeneous: many studies are mechanistic or on animals, and clinical trials are limited in size, duration, and population. Therefore, at present, observations indicate biological plausibility and favorable preliminary results, but do not provide consolidated proof that dietary or supplementary use of cinnamon prevents or cures allergic diseases.

What science says: context and definition

“Antiallergic effect” here refers to the ability to reduce processes that lead to allergic symptoms — for example, mast cell stabilization, reduction of mediators such as histamine, leukotrienes, and certain cytokines, or decreased cellular migration/leaking into tissues. Available evidence ranges from cellular mechanisms identified in the laboratory to results in animal models and a few clinical studies with standardized extracts. This heterogeneity is important: in vitro results show plausible mechanisms but do not automatically predict clinical effects in people in real-world settings. Differences also emerge depending on the botanical species (Cinnamomum verum or C. cassia), the extracted fraction (essential oil, aqueous extract, proanthocyanidins), and the route of use (food, oral in capsules, topical or intranasal application). This review presents the main results and interpretive limitations, with an evidence-based and cautious approach.

Preclinical evidence and mechanisms

Cellular studies indicate that cinnamon extracts can inhibit mast cell degranulation and reduce the synthesis of pro-inflammatory mediators. In particular, experimental research has shown that cinnamaldehyde is one of the compounds that contributes most to this effect, with a dose-dependent reduction in the release of enzymes and cytokines associated with mast cell activation [2]. A study on cell lines and isolated human mast cells reported both decreased degranulation and attenuation of signaling pathways such as ERK and PLCγ1, mechanisms plausibly responsible for the observed effect [1][2].

Other in vivo models show a reduction in tissue inflammation and related markers after treatment with cinnamon extracts: for example, murine models of colitis showed less inflammatory infiltration and a decrease in chemokines and cytokines after extract administration [5]. Furthermore, some fractions derived from cinnamon (IND02) interfere with leukocyte adhesion linked to selectins and sialosides, suggesting an additional anti-inflammatory mechanism potentially relevant in allergic reactions [4].

Available Clinical Evidence

Direct clinical evidence on allergies is limited but exists. A randomized, double-blind, placebo-controlled clinical trial evaluated a nasal spray containing a standardized cinnamon bark extract (IND02) in subjects with seasonal allergic rhinitis: the treated group showed a significant reduction in rhinitis-related quality of life scores and symptoms compared to placebo after seven days of intranasal use [3]. This trial suggests that, in topical and standardized form, cinnamon extracts may have short-term symptomatic effects.

Other clinical studies in the metabolic field show favorable effects of cinnamon extracts on glycemia, insulinemia, and lipid profile in people with elevated glucose or type 2 diabetes, confirming metabolic properties that may be relevant for general health but are not direct proof of efficacy in allergic diseases [6][7][8]. These clinical data highlight the need to distinguish between systemic benefits observed for other targets (metabolism, oxidative stress) and specific anti-allergic efficacy.

What this means in practice

For the general public: data suggest that components of cinnamon can influence key cellular processes in allergic responses and that, in a standardized intranasal topical formulation, symptomatic improvement was observed in a controlled clinical study [3]. However, there is currently insufficient evidence to recommend the routine use of cinnamon as a primary treatment for allergies. The most realistic practical implications for those who want to prudently apply the evidence are as follows:

  • Prefer foods integrated with spices like cinnamon for taste and as part of a varied diet; do not expect immediate therapeutic effects against allergies.
  • If considering a supplement or a specific preparation (e.g., intranasal spray), consult a doctor, especially in the presence of other therapies, clinical conditions, or pregnancy.
  • Keep in mind that safety and efficacy depend heavily on the cinnamon species, the presence of compounds like coumarin (higher in Cassia), and the chosen dose/formulation; standardized extracts used in trials often differ from common food use.

In summary: promising but preliminary; it does not replace validated drugs or therapies for allergies.

Key takeaways

  1. Cinnamon contains compounds (cinnamaldehyde, proanthocyanidins) with anti-inflammatory and mast cell stabilizing activity documented in vitro and in animal models [1][2][5].
  2. A controlled clinical trial on a standardized intranasal spray (IND02) observed a reduction in allergic rhinitis symptoms after 7 days of treatment [3].
  3. Systemic clinical effects (e.g., on glucose metabolism) have been observed in different studies but do not automatically imply anti-allergic efficacy [6][7][8].
  4. The quality of evidence varies: many studies are preclinical or small trials; larger, longer-term clinical studies with clearly described formulations are needed.

Limitations of Evidence

It is crucial to distinguish between levels of evidence. Observational or in vitro experimental studies provide indications of biological mechanisms and plausibility, but do not demonstrate direct clinical causation. Clinical trials on cinnamon and allergy are still limited in number, sample size, and duration [3]. Some trials on metabolism show positive effects but also conflicting results between different studies [6][7][8].

Frequent methodological limitations that reduce certainty include: small sample sizes, short observation periods, lack of independent replication, variability in botanical species and extraction methods. The generalizability of results is also conditioned by the form of preparation (aqueous extract, oil, isolated proanthocyanidins) and the route of administration (intranasal vs. oral). Finally, long-term safety and possible drug interactions (e.g., with anticoagulants or hypoglycemic drugs) require clinical attention and dedicated studies [11][6].

Editorial Conclusion

The evidence gathered shows a plausible anti-allergic activity of cinnamon at the cellular level and some favorable clinical signals in standardized formulations; however, the overall quality of the evidence is not such as to recommend cinnamon as a first-line therapy for allergies. The literature suggests interesting mechanistic pathways and justifies further rigorous clinical studies, with precise descriptions of botanical species, fractions used, doses, and route of administration. In the meantime, moderate dietary use of cinnamon can be considered part of a varied diet, but any therapeutic or integrative decision should be discussed with a healthcare professional.

Editorial note

Article originally published in a previous version and updated to provide a critical and transparent summary of available scientific evidence. The update was carried out with criteria of accuracy, clarity, and verifiable references (DOI). The content is for informational and educational purposes only: it does not replace medical advice, diagnosis, or treatment provided by qualified professionals. For therapeutic choices, always consult your doctor.

SCIENTIFIC RESEARCH

  1. Hagenlocher Y, Bergheim I, Zacheja S, Schäffer M, Bischoff SC, Lorentz A. Cinnamon extract inhibits degranulation and de novo synthesis of inflammatory mediators in mast cells. Allergy. 2013;68(4):490–497. https://doi.org/10.1111/all.12122
  2. Hagenlocher Y, Kiessling K, Schäffer M, Bischoff SC, Lorentz A. Cinnamaldehyde is the main mediator of cinnamon extract in mast cell inhibition. Eur J Nutr. 2015;54(8):1297–1309. https://doi.org/10.1007/s00394-014-0810-0
  3. Steels E, Steels E, Deshpande P, Thakurdesai P, Dighe S, Collet T. A randomized, double-blind placebo-controlled study of intranasal standardized cinnamon bark extract for seasonal allergic rhinitis. Complement Ther Med. 2019;47:102198. https://doi.org/10.1016/j.ctim.2019.102198
  4. Lin WL, Guu SY, Tsai CC, et al. Derivation of cinnamon blocks leukocyte attachment by interacting with sialosides. PLoS One. 2015;10(6):e0130389. https://doi.org/10.1371/journal.pone.0130389
  5. Wang C, Lorentz A, et al. Cinnamon extract reduces symptoms, inflammatory mediators and mast cell markers in murine IL-10−/− colitis. J Nutr Biochem. 2015; (article). https://doi.org/10.1016/j.jnutbio.2015.11.015
  6. Anderson RA, Zhan Z, Luo R, et al. Cinnamon extract lowers glucose, insulin and cholesterol in people with elevated serum glucose. J Tradit Complement Med. 2015;6(4):332–336. https://doi.org/10.1016/j.jtcme.2015.03.005
  7. Khan A, Safdar M, Ali Khan MM, Khattak KN, Anderson RA. Cinnamon improves glucose and lipids of people with type 2 diabetes. Diabetes Care. 2003;26(12):3215–3218. https://doi.org/10.2337/diacare.26.12.3215
  8. Mang B, Wolters M, Schmitt B, et al. Effects of a cinnamon extract on plasma glucose, HbA1c, and serum lipids in diabetes mellitus type 2. Eur J Clin Invest. 2006;36(5):340–344. https://doi.org/10.1111/j.1365-2362.2006.01629.x
  9. Pham H, et al. Cinnamaldehyde improves lifespan and healthspan in Drosophila melanogaster models for Alzheimer’s disease. BioMed Res Int. 2018;2018:3570830. https://doi.org/10.1155/2018/3570830
  10. Mehrpour O, et al. Cinnamon and cognitive function: a systematic review of preclinical and clinical studies. Nutr Neurosci. 2023; (review). https://doi.org/10.1080/1028415X.2023.2166436
  11. Rao PV, Gan SH. Cinnamon: a multifaceted medicinal plant. Evid Based Complement Alternat Med. 2014;2014:642942. https://doi.org/10.1155/2014/642942