Bitter orange (Citrus aurantium), often referred to as sour orange or Seville orange, is a versatile citrus fruit celebrated for its diverse applications. This fruit is widely utilized in complementary medicine, particularly in herbal weight loss supplements, as well as in various culinary delights, including traditional marmalade. Believed to have its roots in Southeast Asia, bitter orange now thrives across regions such as Latin America, the Caribbean, the South Sea Islands, Europe, and parts of Western and Southern Africa. In India, it is sometimes known as kathal, illustrating the fruit's global presence and cultural significance.

This article will delve into the essential aspects of bitter orange, exploring its potential benefits for weight management and skin health, along with an assessment of its overall safety as a dietary supplement.

The Fruit and Its Extracts

The bitter orange plant flourishes in subtropical climates, demonstrating remarkable resilience to challenging environmental factors such as frost, albeit for brief durations. Its fruit, which is oval or oblong in shape, turns a vibrant red-orange hue upon ripening and boasts a notably thick, dimpled skin. As suggested by its name, this fruit possesses a strong bitterness that sets it apart. Among the 23 varieties of bitter orange, the most notable is Bergamot, known for its unique flavor profile. It's important to note that some cultivars may exhibit higher bitterness levels than others, contributing to the diversity in taste.

This citrus fruit is rich in several potent plant compounds, which are frequently extracted from its dried peel to produce various dietary supplements. A well-known extract from bitter orange, p-synephrine, is available in capsule form and marketed under herbal weight loss supplements such as Advantra Z and Kinetiq. In addition to capsules, essential oils, as well as powdered and liquid forms of supplements, can also be found on the market, catering to different preferences and applications.

Compounds and Nutrients

The plant compounds present in bitter orange, known as protoalkaloids, have been utilized for over two decades in various supplements aimed at enhancing weight loss, boosting athletic performance, improving skin health, controlling appetite, and supporting brain function, in addition to their role in perfumery.

Synephrine (p-synephrine)

P-synephrine, the primary extract derived from bitter orange, shares structural similarities with ephedrine, which is the key ingredient in the herbal weight loss supplement ephedra. This particular supplement faced a ban by the U.S. Food and Drug Administration (FDA) due to its association with elevated blood pressure, increased heart rates, and incidents of heart attacks and strokes among certain users. Furthermore, p-synephrine is analogous to your body's fight-or-flight hormones, epinephrine and norepinephrine, which are known to raise heart rates. Consequently, concerns regarding the safety of bitter orange extract have emerged.

Nonetheless, numerous studies indicate that bitter orange extracts and its natural applications do not adversely affect heart health or nervous system function, nor do they stimulate nervous system activity in the way that some stimulants do. Additionally, at least one research study has suggested that p-synephrine should not be classified as a stimulant. It's worth mentioning that p-synephrine is also present in other citrus fruits and their juices, including mandarins and clementines.

Limonene

Similar to other citrus varieties, bitter orange contains limonene, a compound recognized for its anti-inflammatory and antiviral properties. Epidemiological studies indicate that limonene may have a preventive effect against certain cancers, particularly colon cancer; however, further extensive human research is necessary. An ongoing investigation is also examining the potential of limonene as a treatment for COVID-19, although results have yet to be disclosed. It is essential to note that limonene cannot prevent or cure COVID-19.

Octopamine (p-octopamine)

Another protoalkaloid found in bitter orange is p-octopamine, but it exists in minimal amounts in bitter orange extracts. Moreover, it is believed to be metabolized very quickly in the liver when derived from the whole fruit. Consequently, it does not seem to provide any significant beneficial or detrimental effects on the body.

Other Compounds

The leaves of the bitter orange plant are abundant in vitamin C, which serves as a powerful antioxidant. Additionally, the peel is rich in flavonoids, which are strong antioxidants with considerable medicinal benefits. Antioxidants are substances that may shield your body from diseases by thwarting cellular damage. They operate by neutralizing free radicals, unstable molecules that can harm your cells, thereby increasing inflammation and the risk of disease. Protoalkaloids found in bitter orange exhibit both anti-inflammatory and antiviral properties and have been demonstrated to be safe for consumption.

Can Bitter Orange Support Weight Loss?

Bitter orange, along with various other citrus fruits, has garnered attention for its potential role in aiding weight loss; however, the evidence regarding its effectiveness remains limited. Many weight loss supplements incorporate extracts from bitter orange, often combined with other ingredients, yet comprehensive scientific studies have not adequately analyzed these formulations to ascertain which components may actually facilitate weight loss.

A key compound, p-synephrine, has demonstrated the ability to enhance fat oxidation, boost energy expenditure, and slightly curb appetite, all of which could contribute to weight reduction. However, it is important to note that these beneficial effects are linked to high doses that are generally discouraged due to insufficient safety data.

Consequently, there is a pressing need for further research to explore the weight loss potential of bitter orange more thoroughly. While bitter orange extracts are frequently found in weight loss products, the current evidence supporting their efficacy remains scant.

Health Benefits of Bitter Orange

Bitter orange, known as kinnow in certain regions, along with its extracts, has a long history of use in Traditional Chinese Medicine (TCM) for addressing various digestive issues such as indigestion, diarrhea, dysentery, and constipation. In other cultures, particularly in Australia and Japan, this fruit is also utilized for alleviating symptoms of anxiety and epilepsy. However, it is important to note that there is limited scientific evidence backing these medicinal applications.

Moreover, the evidence supporting the use of bitter orange for alleviating symptoms of premenstrual syndrome (PMS) is also lacking. While some animal studies, particularly involving older rats, have suggested that flavanone compounds found in citrus fruits and their juices could potentially enhance thyroid function, it is not safe to assume these effects translate to humans. Despite these uncertainties, the high vitamin C content of bitter orange suggests potential benefits for skin health. The role of vitamin C in wound healing and collagen synthesis is widely recognized and well-documented.

Additionally, research has indicated that a specific compound in bitter orange, known as p-synephrine, may enhance athletic performance by increasing total repetitions and the volume load during training, thereby enabling individuals to push their limits further. Nevertheless, it is crucial to understand that the effectiveness of bitter orange and its extracts for various medicinal purposes remains largely unproven.

Potential Risks and Adverse Effects of Bitter Orange

The debate continues regarding synephrine, a natural compound found in bitter orange, and whether it qualifies as a stimulant. A stimulant is typically defined as a substance that elevates heart rate and blood pressure. In fact, various sports organizations, including the National Collegiate Athletic Association (NCAA), categorize synephrine as a stimulant, leading to its classification as a banned substance in competitive sports.

Moreover, research has indicated that bitter orange juice contains furanocoumarin, a compound that may interact with medications similarly to grapefruit juice. As a result, individuals who are on decongestants or those suffering from conditions like high blood pressure, irregular heartbeats, or glaucoma should refrain from consuming bitter orange juice and the fruit itself. The risks associated with bitter orange supplements, however, remain uncertain.

Though numerous studies have suggested that bitter orange extracts do not act as stimulants, the controversy persists, prompting the NCAA to maintain its ban. Additionally, it's essential to acknowledge that bitter orange could potentially interact with various medications, highlighting the need for caution.

Dosage and Safety Information

Generally speaking, extracts from bitter orange (Citrus aurantium) are considered safe for consumption when taken in doses ranging from 50 to 98 mg per day. In one noteworthy study, a combination of 40 mg of synephrine with 320 mg of caffeine was found to be a safe dosage for these two ingredients when used together. Furthermore, another investigation involving the consumption of a whole bitter orange, which contains approximately 30.6 mg of p-synephrine, indicated that there were no significant interactions with medications. However, it is important to note that individuals who are pregnant or breastfeeding are advised to steer clear of bitter orange, primarily due to insufficient safety data. Overall, while bitter orange appears to be safe within a dosage range from 30.6 mg of synephrine found in the fruit to 98 mg in dietary supplements, further research is necessary to determine its long-term effects and safety.

Culinary Applications of Bitter Orange

The taste of bitter orange is notably tart, making it quite rare to consume it raw. This citrus fruit is exceptionally rich in pectin, a natural gelling agent, which makes it ideal for preparing delicious marmalade.

Furthermore, the oil extracted from bitter orange serves as a flavoring agent or additive in a variety of culinary delights, including:

• preservatives (such as jellies)
• confectionery (like chewing gum, hard candies, and candied fruits)
• sweets (ice creams and pies)
• condiments including sauces and chutneys
• salad dressings
• fermented beverages, including wine

The juice of bitter orange can effectively function as a marinade, enhancing the flavors of both fish and meat. In various regions, it is often utilized similarly to vinegar, providing a zesty kick. Moreover, the oils extracted from this fruit impart a unique flavor to liqueurs such as Grand Marnier. In China, bitter orange is commonly used to brew herbal teas and formulate traditional medicines.

Additional Applications

Apart from its culinary uses, bitter orange boasts numerous applications in household settings. These include:

• soap alternatives
• essential oils (including neroli and petitgrain)
• fragrance creation
• traditional remedies (like antiseptics and hemostatics)

The Bottom Line

Bitter orange, a unique citrus fruit, is frequently transformed into a concentrated extract, showcasing its versatility in the culinary world, although it is seldom consumed in its whole form. This fruit has found its way into various dishes and beverages across cultures, adding a distinctive flavor profile.

While bitter orange supplements are generally regarded as safe when taken in standard dosages, the evidence supporting their effectiveness for weight reduction, thyroid function, and skin health remains inconclusive. Different regions, such as India, Australia, Japan, and Canada, may have varying perspectives on its uses, with some culinary traditions incorporating it more than others.

Individuals with conditions like high blood pressure, irregular heart rhythms, or glaucoma are advised to exercise caution and potentially avoid this fruit and its extracts. Furthermore, it's important to note that bitter orange supplements are prohibited for NCAA athletes, reflecting concerns about their safety and performance-enhancing potential.