What Is Bitter Orange?
Bitter orange (Citrus aurantium) is a type of tree that grows in the Mediterranean region, as well as in California, Florida, and other parts of the world. Extracts of the tree's flowers, leaves, and dried fruit and peel are used in herbal medicine.
Uses for Bitter Orange
Bitter orange is also purported to help treat heartburn, loss of appetite, and nasal congestion, as well as promote weight loss. Some proponents recommended applying bitter orange topically to treat fungal infections (such as ringworm and athlete's foot).
Benefits of Bitter Orange
According to the National Center for Complementary and Alternative Medicine, there is not enough scientific evidence to support the use of bitter orange for health purposes. Indeed, no studies have shown that the herb is useful in treatment of nausea, indigestion, constipation, heartburn, nasal congestion, or fungal infections.
Bitter Orange for Weight Loss
In recent years, bitter orange has been marketed as a natural weight-loss aid. Proponents claim that bitter orange helps stimulate the fat-burning process.
In several small studies, participants have experienced an increase in metabolic rates when consuming bitter orange products. However, researchers have yet to confirm that bitter orange is beneficial to people wanting to lose weight.
What's more, bitter orange contains two compounds (synephrine and octopamine) that are structurally similar to those found in ephedra (an herb banned by the U.S. FDA because it raises blood pressure and is linked to heart attacks and strokes). Synephrine has been found to increase blood pressure in humans, and may increase risk of cardiovascular events.
Safety Concerns for Bitter Orange
Because of its potential to cause abnormal heart rhythms, raise blood pressure, and speed up heart rate, bitter orange should only be used under the direction of a physician. Anyone with a cardiovascular condition (such as heart disease or high blood pressure) or diabetes should avoid bitter orange.
Bitter orange should not be combined with caffeine or any natural substances containing caffeine (such as green tea and yerba mate). It should also be avoided by anyone taking medications (such as MAO inhibitors) or herbs/supplements that increase heart rate.
Due to lack of safety evidence, pregnant women should avoid products that contain bitter orange.
Adverse Effects of Bitter Orange
According to the National Center for Complementary and Alternative Medicine, there have been reports of fainting, heart attack, and stroke in healthy people after taking bitter orange supplements alone or combined with caffeine.
When topically applied, bitter orange oil may increase the risk of sunburn, particularly in light-skinned people.
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Klontz KC, Timbo BB, Street D. "Consumption of dietary supplements containing Citrus aurantium (bitter orange)--2004 California Behavioral Risk Factor Surveillance Survey (BRFSS)." Ann Pharmacother. 2006 40(10):1747-51.
National Center for Complementary and Alternative Medicine. "Bitter Orange: Herbs at a Glance [link: http://nccam.nih.gov/health/bitterorange/]." NCCAM Publication No. D390 Created August 2007 Updated November 2008.
Preuss HG, DiFerdinando D, Bagchi M, Bagchi D. "Citrus aurantium as a thermogenic, weight-reduction replacement for ephedra: an overview." J Med. 2002;33(1-4):247-64.