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A feel-good fruit, bitter or sour orange is said to calm frazzled nerves, and science has confirmed its ability to calm, relax, and act as a mild sedative.
About the plant: A small tree from Asia, East Africa, Arabia, and Syria, it’s cultivated in the Mediterranean, the southern United States, South Africa, Australia, and the Caribbean to produce the fruit used in marmalade. Its bitterness distinguishes it from close relatives bergamot and sweet orange. It has long, leathery green leaves, and its sweet-fragranced, yellowish-white flowers make one of the most beautifully scented essential oils.
History and folklore: A universal calming balm, bitter orange has been traditionally used in Chinese, Japanese, Ayurvedic, South American and Western herbal medicine for anxiety, as a sedative for minor insomnia, in epilepsy, and as a tonic to strengthen the nervous systems of adults and children. Basque people have historically used its leaves for insomnia and palpitations. The oils are used in perfumery, and the oil and peel in flavoring such as orange liqueurs. Bitter orange is added to supplements to increase appetite and help weight loss.
What scientists say
In humans: Bitter orange flower extracts and inhalation of its beautifully scented essential oil (neroli) have been shown in initial clinical trials to significantly reduce anxiety. Neroli essential oil also clinically reduces blood pressure and anxiety and improves sleep in coronary patients when inhaled with lavender and Roman chamomile. It reduces blood pressure and cortisol levels in hypertension when inhaled with other essential oils. Bitter orange extract has also been shown to alleviate anxiety and pain in labor. Commercial extracts, not the essential oil, increased blood pressure in some but not all trials. In a controlled trial, sweet orange (Citrus × sinensis) improved cognitive function in older people.
In the lab: Studies show bitter orange is sedative, reduces spasms, and is anticonvulsant via the brain’s calming (GABA) signal and also by blocking the brain’s stimulatory (glutamate) signal. It also has antidepressant effects via the mood-boosting (serotonin) neurotransmitter, and the flower extract, peel, and seeds are the all-important neuroprotective with antioxidant and anti-inflammatory properties.
Key ingredients: Contains naringin (also in bergamot and grapefruit), a flavonoid studied for use in anxiety, epilepsy, for memory, and as a neuroprotective. Contains the sedative ingredient hesperidin which is also in passionflower and valerian. Fruit and flower contain alkaloids that have adrenergic (weight loss) effects. Essential oils from bitter orange don’t contain the alkaloids. Three essential oils are produced from different parts of this plant—“bitter orange” (from peel), “neroli” (from flowers), and “petitgrain” (from leaves and wood, which can sometimes confusingly include essential oils from other plants). Neroli contains linalool (the constituent in lavender and other calming plants) and the peel oil differs in being almost identical to sweet orange.
How to take it: Best for calming is neroli essential oil used in aromatherapy. Fresh flower tea or peel decoction, tincture, or extracts are also commonly used. Cook with peel syrup, try bitter orange caramelized potatoes, or simply enjoy marmalade on toast.
Safety: At medicinal doses of the extract, not in heart conditions, high blood pressure, glaucoma, ischemic colitis, or with monoamine oxidase inhibitors for depression. Juice may increase bioavailability of drugs, similar to grapefruit. Bitter orange peel (not neroli flower) oil is moderately phototoxic (do not use above 1 percent on skin application). The extract can increase heart rate; take care when using supplements where active ingredients may be increased and where caffeine increases this effect.
Bitter orange extract is regulated by the US Food and Drug Administration on account of its overuse in weight loss supplements. The peel, oil, and extracts are generally recognized as safe (GRAS) as a direct additive to food.
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Cover courtesy of The Experiment Publishing
Excerpted from Your Brain on Plants: Improve the Way You Think and Feel with Safe—and Proven—Medicinal Plants and Herbs © Nicolette Perry and Elaine Perry, 2018. Reprinted by permission of the publisher, The Experiment. Available wherever books are sold. The experimentpublishing.com