What is Bitter Orange (Citrus aurantium)?
Bitter orange, also known as Seville orange, is a citrus fruit native to Southeast Asia. Its fruit is bitter and used for marmalade and liqueurs, while the flowers, leaves, and fruit peel are utilized in herbal medicine. The plant contains various phytochemicals.
Key Active Compounds
Bitter orange's effects are mainly due to alkaloids and flavonoids.
- Alkaloids: The main alkaloid is p-synephrine, a less potent stimulant than ephedrine. Other related compounds include octopamine and tyramine.
- Flavonoids: The peel contains flavonoids like naringin, hesperidin, and nobiletin, known for antioxidant and anti-inflammatory properties.
- Essential Oils: Neroli oil from flowers and petitgrain from leaves contain compounds like limonene and linalool, used in aromatherapy for calming effects.
Traditional and Modern Uses for Bitter Orange
Bitter orange has traditional uses and is also studied in modern research.
Digestive Health Support
Traditionally, bitter orange has been used in Chinese medicine for digestion.
- Appetite and Digestion: The bitter taste of the peel is used to stimulate appetite and aid digestion.
- Indigestion Relief: Extracts are traditionally used for dyspepsia, flatulence, and constipation.
- Stomach Protection: Some research suggests essential oil compounds may support stomach lining protection.
Anxiety and Relaxation
Essential oils from bitter orange flowers are used for calming effects.
- Aromatherapy: Neroli oil from flowers is used to ease stress and anxiety.
- Anxiolytic Effects: Studies have shown bitter orange essential oil can improve anxiety symptoms.
Antioxidant and Anti-inflammatory Action
Flavonoids and vitamin C in bitter orange provide antioxidant and anti-inflammatory benefits, protecting cells from damage.
Controversial Weight Management
Following the ephedra ban, bitter orange extracts with synephrine were used in weight loss supplements. Its effectiveness and safety are debated.
- Thermogenic Effect: Synephrine is marketed to increase metabolism and energy expenditure.
- Fat Oxidation: Some studies suggest synephrine may increase fat oxidation during exercise.
- Mixed Evidence: Other studies show no significant weight loss from bitter orange alone, and findings on exercise performance are inconsistent.
Bitter Orange Extract vs. Other Stimulants
Bitter orange extract differs from other stimulants like ephedra and caffeine in its regulatory status and safety profile. The table below provides a comparison.
| Feature | Bitter Orange (Synephrine) Extract | Ephedra (Ephedrine) | Caffeine |
|---|---|---|---|
| Primary Mechanism | Stimulates adrenergic receptors, leading to thermogenesis and increased metabolism. | More potent stimulation of the nervous system and heart; banned by FDA for supplements. | Central nervous system stimulant; inhibits adenosine, increasing alertness and energy. |
| Cardiovascular Effects | Studies show mixed results; can increase heart rate and blood pressure, especially when combined with other stimulants. | Significant and proven risks of increased heart rate, blood pressure, and cardiovascular events. | Can increase heart rate and blood pressure, though generally considered safer at moderate doses than ephedrine. |
| Regulatory Status | Allowed as a dietary ingredient, but controversial and banned by organizations like the NCAA. | Banned by the U.S. FDA in dietary supplements due to significant health risks. | Widely legal and unregulated in supplements, often combined with bitter orange. |
| Associated Risk | Potential for adverse cardiovascular events, particularly with stimulants; concerns over adulterated products. | High risk for serious cardiovascular issues, stroke, and heart attack. | Risk of nervousness, increased heart rate, and jitteriness; potential for dependency. |
Safety Considerations and Interactions
While safe in food amounts, medicinal use of bitter orange requires caution due to the stimulant effects of synephrine.
Potential Side Effects
- Cardiovascular: Bitter orange with other stimulants may increase blood pressure and heart rate, risky for those with heart conditions.
- Photosensitivity: Applying bitter orange essential oil to skin can increase sun sensitivity.
- Migraines: Some reports suggest it may trigger headaches.
Drug Interactions
Bitter orange can interact with many medications by affecting liver enzymes.
- MAOIs and Antidepressants: Can cause very high blood pressure and rapid heart rate.
- Calcium Channel Blockers: May increase effects of certain medications.
- QT-Prolonging Drugs: Can increase risk of serious heart issues.
Populations to Avoid
Certain groups should avoid bitter orange supplements:
- Pregnant and breastfeeding women
- Individuals with heart disease, high blood pressure, or irregular heartbeats
- Those with glaucoma
- Patients taking certain medications metabolized by the CYP3A4 enzyme
- Anyone having surgery within two weeks
For more information on bitter orange safety, consult resources like the National Center for Complementary and Integrative Health (NCCIH) at https://www.nccih.nih.gov/health/bitter-orange.
Conclusion
What bitter orange does for the body varies depending on the part used and concentration. Traditional uses for digestion and anxiety are documented, as are its antioxidant properties. However, its use in weight loss supplements is controversial and poses risks, especially cardiovascular. Bitter orange extracts with synephrine should be used cautiously due to interactions and side effects. Consult a healthcare provider before using any bitter orange supplement.
Note: This article provides general information and is not a substitute for professional medical advice. Always consult a healthcare professional before starting any new supplement regimen.
