Are Natural Herbs Really Safe?
As a gastroenterologist and digestive system specialist, I increasingly see patients in my practice who come in worried about abnormal blood test results without knowing why. When we dig deeper into their medical history, we frequently discover they’ve been taking herbal supplements they consider “completely natural and safe.”
This belief – that natural equals safe – is one of the most dangerous myths circulating today. The reality is that many herbs sold as supplements can cause serious liver damage, even leading to situations requiring liver transplantation.
Ashwagandha: The Adaptogen That Can Be Toxic
What is Ashwagandha?
Ashwagandha, also known as “Indian ginseng,” has become extremely popular in recent years. It’s marketed as an “adaptogen” – a substance that supposedly helps the body manage stress, anxiety, and fatigue.
Current Scientific Reality
According to the National Center for Biotechnology Information in the United States, although initially considered safe, recent cases have documented serious liver injuries associated with its consumption NCBI LiverTox.
Patients who develop liver problems from ashwagandha typically present symptoms between 2 and 12 weeks after starting to take it. Symptoms include:
- Yellowing of skin and eyes (jaundice)
- Intense itching
- Extreme fatigue
- Nausea and vomiting
- Abdominal pain
Documented Cases
A study published in 2020 analyzed five cases of liver injury associated with ashwagandha. Most concerning is that cases requiring emergency liver transplantation have been reported and even fatal cases, especially in people who already had liver problems.
Kava: The Herb Banned in Europe
What is Kava?
Kava comes from the roots of the Piper methysticum plant and has been traditionally used in Pacific islands as a ceremonial drink. In the West, it’s sold as a supplement for anxiety and insomnia.
Why is it Banned?
Kava represents one of the most documented cases of herbal liver toxicity. Between 50 and 100 cases of liver injury attributable to kava have been identified, including cases of liver failure requiring transplantation NCBI LiverTox.
Countries That Have Banned It
Due to these risks, kava has been banned or restricted in multiple European countriesincluding:
- Germany
- Switzerland
- France
- Canada
- Great Britain
Real Documented Case
A particularly severe case involved a 22-year-old woman who developed acute liver failure after taking kava for 4 months. She required emergency liver transplantation and sadly died months later from complications.
Green Tea Extract: When Concentration is Dangerous
The Key Difference
While drinking green tea is generally safe, concentrated extracts present different risks. A University of Michigan study warns about increased liver toxicity due to these concentrated extracts CuidatePlus.
When is it Dangerous?
Problems arise when:
- Highly concentrated extracts are consumed
- High doses are taken
- Combined with other supplements
- Used for prolonged periods
Other Herbs That Can Damage Your Liver
Black Cohosh (Cimicifuga)
Used primarily for menopausal symptoms, it has been associated with severe hepatitis. According to Mayo Clinic, it’s among the herbs considered dangerous for the liver Mayo Clinic.
Chaparral
Marketed as an antioxidant, it has caused acute hepatitis and liver failure. Several cases have required liver transplantation.
Comfrey
Contains substances called pyrrolizidine alkaloids that can cause severe and potentially fatal liver disease.
Valerian
Although widely used as a natural sedative, it has been associated with hepatitis in some cases.
How Does Liver Damage Occur?
Main Mechanisms
Damage can occur in several ways:
- Direct toxicity: Plant components directly attack liver cells
- Unpredictable reactions: Some people are more susceptible than others
- Immune system reactions: The body attacks its own liver
- Contamination: Presence of heavy metals or pesticides
- Adulteration: Undeclared medications mixed with the herb
Factors That Increase Risk
Who is at Greater Danger?
- People with previous liver disease: Risk multiplies significantly
- Those taking medications: Can interact dangerously
- Use of excessive doses: More is not better
- Prolonged use: Extended exposure increases risk
- Products of dubious quality: Without adequate quality control
Warning Symptoms: When to Worry
Warning Signs
If you take any herbal supplement, you should watch for:
- Unusual and persistent fatigue
- Nausea and vomiting without apparent cause
- Pain in the upper right abdomen
- Yellowing of skin and eyes
- Intense itching throughout the body
- Very dark urine
- Very light or white stools
What to Do if Symptoms Appear
- Immediately stop the supplement
- Seek urgent medical attention
- Bring the product container to show the doctor
- Don’t wait for symptoms to worsen
Diagnosis: How is it Detected?
The Medical Challenge
Diagnosing liver damage from herbs is complicated because:
- Symptoms can be similar to other diseases
- People often don’t mention they take supplements
- Other causes must be ruled out first
Necessary Tests
- Blood tests: To see how the liver is functioning
- Detailed history: About all supplements consumed
- Tests to rule out: Viral hepatitis, autoimmune diseases
- Imaging studies: Ultrasound or MRI of the abdomen
Treatment: What Can Be Done?
Medical Management
Treatment primarily consists of:
- Immediate cessation: Stop taking the suspected herb
- Constant monitoring: Close medical follow-up
- Nutritional support: Especially in severe cases
- Avoid further damage: No alcohol, careful with other medications
- Transplantation: In very severe cases may be necessary
Recovery Time
- Mild cases: May recover in 1-3 months
- Moderate cases: May take 3-6 months
- Severe cases: May require transplantation or be fatal
Recommendations for Safe Herb Use
Before Starting Any Supplement
- Mandatory medical consultation: Especially if you have liver problems
- Scientific research: Look for information in reliable sources
- Product quality: Choose brands with serious certifications
- Respect doses: Don’t exceed quantities
- Stay alert: Know the warning symptoms
During Use
- Monitor your body: Any strange symptom is important
- Periodic tests: If use is prolonged
- Inform your doctor: About all supplements you take
- Avoid mixtures: Don’t combine multiple herbs without supervision
My Perspective as a Physician
Debunking Beliefs
As a digestive system specialist, I constantly see the consequences of the erroneous belief that “natural is always safe.” Medicinal plants contain active substances that can be as potent as pharmacy medications, and therefore, can cause serious adverse effects.
The Importance of Communication
Honest communication between patients and doctors about supplement use is fundamental. Often people don’t mention they take herbs because they believe it “doesn’t count” or that the doctor won’t take it seriously.
Important Conclusions
What You Should Remember
- Natural is not synonymous with safe: Herbs can be toxic
- Dose matters: More is not better
- Quality is crucial: Not all products are equal
- Your liver is vulnerable: Especially if you already have problems
- Symptoms are serious: Don’t ignore them
The Balanced Approach
It’s not about prohibiting all herbs, but using them with knowledge and caution. Integrative medicine should be based on scientific evidence, not popular beliefs or aggressive marketing.
Final Message
Your health is too valuable to risk with unregulated products. Always consult with a healthcare professional before starting any herbal supplement, especially if you have pre-existing medical conditions.
Remember: in medicine, prevention is always better than treatment. Stay informed, stay safe.
Dr. Pedro de María Pallarés
Expert in Gastroenterology and Advanced Endoscopy
Hospital Universitario La Paz – INMEQ
TopDoctors® Awards 2024