The term 'myrtle' can refer to several different plants, each with distinct properties and potential dangers. Understanding the specific botanical name of the plant is critical, as assuming one variety is safe based on another's reputation can have severe, and even fatal, consequences. The most significant risks are associated with the undiluted essential oils, particularly common myrtle and the highly toxic bog myrtle.
Side Effects of Common Myrtle (Myrtus communis)
Common myrtle essential oil is extracted from the leaves and branches of the Myrtus communis plant. While the berries may be used in certain culinary applications, the oil is considered highly unsafe for internal use. Ingestion of the oil has been linked to a range of severe adverse effects.
- Respiratory Distress: Chemicals within the oil can cause asthma-like attacks and, in severe cases, lung failure. This is a particular risk for children, where even minor contact with the oil can cause fatal breathing problems.
- Gastrointestinal Issues: Overconsumption or accidental ingestion can trigger nausea, vomiting, and diarrhea.
- Circulatory Problems: Other systemic problems, including low blood pressure and blood circulation disorders, have been reported.
Safety Precautions for Common Myrtle Oil
Essential oils are highly concentrated substances and should not be used without proper knowledge. Here are key precautions.
- Never ingest undiluted myrtle essential oil. This is the most dangerous form of exposure.
- Avoid use on children. Given the serious respiratory risks, especially to infants, common myrtle oil is unsafe for pediatric use.
- Do not use if pregnant or breastfeeding. The oral consumption of common myrtle is considered unsafe for pregnant and breastfeeding women.
- Use caution with topical application. Diluted myrtle leaf extract is possibly safe for skin application but may cause irritation or dryness. Always perform a patch test first.
Toxicity of Bog Myrtle (Myrica gale)
Bog myrtle is a separate species with different, and potentially more dangerous, side effects. This plant contains a potent neurotoxin called picrotoxin, which is extremely dangerous when ingested, even in small quantities. Its use is generally not recommended due to these severe risks.
- Fatal Ingestion: Accidental ingestion can be fatal, requiring immediate medical treatment.
- Neurological Symptoms: Picrotoxin can overstimulate the central nervous system, leading to coordination problems, convulsions, twitching, and depression.
- Gastrointestinal Distress: It also irritates the stomach and intestines, causing nausea, vomiting, and increased bowel movements.
- Cardiac and Respiratory Effects: Bog myrtle can cause an irregular or reduced heartbeat and rapid breathing.
- High-Risk Groups: Pregnant women must strictly avoid bog myrtle due to its toxic and abortive components.
Lemon Myrtle (Backhousia citriodora) Side Effects
Lemon myrtle is an Australian native plant often used in culinary preparations and as an essential oil. While considered safer than common or bog myrtle, caution is still warranted with its concentrated essential oil.
- Essential Oil Cytotoxicity: In vitro studies have shown that lemon myrtle oil and its component, citral, can be toxic to human skin cells. While diluted topical products may be low-toxicity, ingesting the undiluted essential oil is not recommended.
- Skin Irritation: Similar to other concentrated essential oils, it can cause skin irritation or allergic reactions.
Common vs. Bog vs. Lemon Myrtle Comparison
To highlight the crucial differences in toxicity, the table below compares these three common 'myrtle' varieties. Botanical identity is paramount when considering any herbal remedy.
| Feature | Common Myrtle (Myrtus communis) | Bog Myrtle (Myrica gale) | Lemon Myrtle (Backhousia citriodora) |
|---|---|---|---|
| Toxic Compound | 1,8-cineole, limonene | Picrotoxin | Citral (highly concentrated) |
| Toxicity Level | High (especially oil) | Extremely High (fatal) | Low to Medium (essential oil cytotoxic) |
| Ingestion Safety | Unsafe (oil), unknown (leaf/berry) | Unsafe (fatal) | Unsafe (undiluted oil) |
| Topical Safety | Possibly safe (diluted extract) | Potentially unsafe | Possibly safe (diluted) |
| Primary Risk | Respiratory failure, GI upset | Neurological damage, GI effects | Skin irritation (oil) |
Who Should Avoid Myrtle?
Due to the varied and potent side effects, certain individuals should avoid myrtle in all its forms unless advised by a qualified healthcare professional. This is especially true for essential oil preparations and bog myrtle.
High-risk populations include:
- Children and Infants: Due to extreme respiratory sensitivity to essential oil.
- Pregnant and Breastfeeding Individuals: Oral use is particularly unsafe and should be avoided. Bog myrtle, in particular, is abortive.
- Individuals with Pre-existing Respiratory Conditions: Conditions like asthma can be exacerbated by myrtle oil's effect on lung function.
- Individuals with Sensitive Skin: Potential for topical irritation, especially from concentrated oils.
- Anyone Considering Internal Use: Never consume myrtle essential oil without expert medical guidance due to significant systemic toxicity.
What to Do in Case of Accidental Exposure
Accidental ingestion or severe exposure to myrtle essential oil or toxic varieties like bog myrtle is a medical emergency. Immediate action is critical. Call emergency services or a poison control center immediately for guidance. Provide as much information as possible, including the specific myrtle species (if known), the amount of oil or plant material involved, and the method of exposure.
For less severe topical reactions, discontinue use and wash the affected area thoroughly with soap and water. If irritation persists, consult a healthcare provider.
Conclusion: Exercise Extreme Caution with Myrtle
Myrtle's reputation as a traditional remedy should not overshadow the serious and scientifically documented side effects, especially with its potent essential oil. Differentiation between species is critical; while crape myrtle is non-toxic, common myrtle oil is seriously harmful if ingested, and bog myrtle contains lethal neurotoxins. Individuals, particularly children and pregnant women, should avoid internal consumption and use topical preparations with extreme caution. Always consult a healthcare professional before incorporating myrtle into any wellness routine. Ignoring these precautions could lead to severe health consequences. Poison Control Center guidance on plant exposure
