Bitter melon is a fruit that grows in the tropics of South America, Asian, Caribbean, and Africa. This plant belongs to the same family as many supermarket favorites like squash, zucchini, watermelon, and cucumber. The fruit is eaten as food or used for medicinal purposes. Knowledge about the potential benefits of bitter melon dates back thousands of years to ancient systems of medicine that sought to use plants to address challenges of the mind and body.
One such ancient system of medicine, Ayurveda, used the plant for its astringent (bitter) taste. According to Ayurvedic practitioners, bitter melon helps to balance the pitta and kapha doshas. When in balance, pitta and kapha doshas may experience optimal digestion, abdominal comfort, respiratory health, and temporary relief from occasional coughing.
In modern and more traditional systems of medicine, researchers are examining bitter melon and its natural chemical properties for its potential to help maintain blood sugar already within the normal range, fat metabolism, healthy-looking skin, the pancreas, and the immune system.
Bitter melon is available in many forms. These include whole fruit, supplements, and as a tea. There are several ways to enjoy its many potential benefits, but is it right for everyone? Read on to discover more about bitter melon.
What Is Bitter Melon?
Bitter melon is a tropical and subtropical vine that is known by the scientific name Momordica charantia, bitter gourd, bitter squash, balsam, bitter apple, and carilla fruit. (1) The vine grows lobed leaves, yellow flowers, and fruit. The fruit looks like a cucumber but with more distinctive surface bumps. When cut open, the fruit has a white-yellow fleshy mesocarp that surrounds its peanut-shaped seeds. The fruit is the most sought after part of the plant, but the leaves, vine, and root can also be consumed. As its name suggests, bitter melon has an astringent taste that is the result of the chemical momordicin. Those not familiar with the taste may need time to acquire a taste before they can fully enjoy its “assertiveness” when compared to other “mild-mannered vegetables.” (2)
Bitter Melon Potential Benefits
Bitter melon contains vitamins, minerals, phytochemicals (antioxidants), and other plant compounds that may provide potential health benefits. Bitter melon has a high daily value of vitamins like vitamin A and C, all eight B vitamins; minerals like calcium, copper, iron, magnesium, manganese, zinc; and phytonutrients beta and alpha-carotene, and lutein-zeaxanthin.
The nutrients found in bitter melon may help to fill nutritional gaps and provide the body with chemical compounds that support several bodily systems and functions including:
- Abdominal comfort
- Respiratory health
- Healthy-looking skin
- Blood sugar already within the normal range
- Healthy weight management
- Fat metabolism
- Pancreatic function
- Immune system
Modern researchers continue to evaluate this plant for its potential uses in alternative therapy or in support of modern treatment methods. In fact, it is estimated that the use of alternative medical therapy as a sole method of treatment, or in conjunction with existing treatments, is gaining popularity. (3) In a 2007 study, it was found that approximately 38 percent of adults, and 12 percent of children, are using some form of complementary or alternative therapy. Forms of these therapies may include deep breathing exercises, meditation, massage therapy, yoga, natural products, homeopathy, and diet.
Several studies have looked into the potential of bitter melon to help maintain blood sugar (glucose) already with the normal range. How bitter melon may support blood sugar levels in the body is believed to be the result of compounds found in the fruit. (4) Specifically, bitter melon contains charantin (5) , polypeptide-p (6) , vicine (7) , and other compounds related to the fruit’s bitter taste, including momordicoside K and L, and momordicin I and II. (8)
To help regulate glucose in the body, the pancreas produces insulin that then enters the bloodstream where it stimulates the “uptake of glucose by different cells of the body for the production of energy.” (9) In a study evaluating the “hypoglycemic effect of bitter melon compared with metformin in newly diagnosed type 2 diabetes patients,” researchers randomized patients into four groups and gave them bitter melon and measured blood sugar levels. (10) Daily doses of bitter melon were either 500 mg, 1,000 mg, 2,000 mg, or a dose of metformin (an antidiabetic medication) at 1,000 mg. The measure of patients’ fructosamine (glucose levels over the previous 2-3 weeks) was assessed at four weeks. The metformin group saw the largest declines, as did the 2,000 mg bitter melon group. The group that was given a dose of 500 mg and 1,000 mg saw the smallest declines.
In a study examining the effects of bitter melon juice, researchers from the University of Central Lancashire, Preston, England, note that bitter melon can “regulate glucose uptake into jejunum membrane brush border vesicles and stimulate glucose uptake into skeletal muscle cells similar to the response obtained with insulin.” (11) Another study involving several researchers from the Kangbuk Samsung Hospital, Seoul, Korea, also found that bitter melon “exerted preventive effects against insulin resistance and diabetes through the modulation of NF-KB and JNK pathways.” (12)
At the Medical School of Ondokuz Mayıs University, Samsun, Turkey, researchers examined the potential benefits of bitter melon cream on the skin. (13) Several factors are involved in the production and maintenance of skin, so researchers measured inflammatory cells, fibroblasts, the size of the epidermis and dermis, collagen fibers, and blood vessels. The research found that bitter melon cream did “improve and accelerate” the process of skin development.
Metabolism and Weight Management
Several studies looked into the potential effect of bitter melon on metabolism and healthy weight management. In a study from the University of Hong Kong, Pokfulam, Hong Kong, bitter melon juice was given in conjunction with a low and high fat diet. (14) As a control, the same diet was given but without bitter melon juice. Over the course of seven weeks, analysis of fat tissue accumulation was measured and found that in both bitter melon juice groups, fat accumulation had decreased. This is believed to be the result of compounds found in bitter melon that “increased fatty acid oxidation which ultimately facilitates weight reduction.” Additionally, the area around the abdomen and pelvis saw less fat deposits in the group that received the high fat diet and bitter melon.
In a similar study involving high fat diets, researchers at the College of Nursing, Central Taiwan University of Science and Technology, Taichung, Taiwan, studied the effect of bitter melon “insulin resistance and visceral obesity.” (15) In the conclusion of the study, researchers note that “bitter melon significantly decreased the weights of epididymal white adipose tissue and visceral fat, and decreased the adipose leptin and resistin mRNA levels.” However, the exact mechanisms by which bitter melon contributes to these potential benefits are not entirely understood. According to the study, it is speculated that bitter melon exerts some influence over gene expression in the DNA found in the liver and fat tissue, which is what contributes to the decrease of glucose levels and fat cell production.
Bitter melon contains bioactive chemical constituents that have been studied for the effect on immune and liver function. These include “ triterpenoids, triterpene glycosides, phenolic acids, flavonoids, essential oils, saponins, fatty acids, and proteins.” (16) A study from Saint Louis University, St. Louis, Missouri, identified bitter melon extract as having demonstrable effect on natural killer (NK) cell-mediated cytotoxicity, which is a function of the immune system that identifies cells for removal from the body or destruction. (17)
Researchers at the Faculty of Human Life and Science, Doshisha Women's College of Liberal Arts, Kyoto, Japan, report that bitter melon “induced a decrease in the intestinal secretion of IL-7 and an increase in the secretions of TGF-beta and IL-10, these effects reflecting the bitter gourd-induced changes in systemic immunity.” (18) They go on to note that the “decrease in the number of lymphocytes, increases in the populations of Th cells and NK cells, and an increase in the Ig production of lymphocytes.” The study concludes by suggesting that “bitter gourd may, therefore, induce both intestinal and also systemic anti-inflammatory responses.” However, the availability of other studies that mirror these findings is limited. Other studies into this area may be necessary to validate these claims.
Pitta and Kapha
Ayurveda is an ancient system of medicine that is still largely practiced in India and has spread to other parts of the world. (19) This system of medicine holds that all of material existence is made up of five elements: earth, water, fire, wind, and ether. Ayurveda also states that people, having been born of existence, contain these elements in different amounts, which is expressed in each dosha, known as pitta, vata, or kapha.
Each person has a dominant dosha, while the other doshas remain sub-types. When in balance, the doshas provide favorable traits and a positive health state. When out of balance, they can cause negative traits and a poor health state. In order to balance the dosha’s, Ayurvedic practitioners recommend specific foods for the qualities they possess. As bitter melon has an astringent taste, it is said to balance the heat of the pitta, and to a lesser degree, the kapha.
Bitter Melon Tea
Along with conventional methods of taking supplements (capsules, tablets, and pills), the potential benefits of bitter melon may be enjoyed as a beverage. This can include adding whole or part of the fruit into a juicer and mixing it with other fruits and vegetables.
However, bitter melon may be less available in every region, placing the fresh fruit out of reach of many consumers. This is why bitter melon tea may be the ideal way of enjoying the plant. (20) The tea is made from either dehydrated leaves or fruit. The whole loose leaves or fruit can be found pre-packaged or in tea bags that are ready to use.
To use the prepackaged variety that is not already in tea bags, wash and chop up the dried fruit or leaves equivalent to 6-8 tablespoons. Boil 16 oz of water, then add the fruit or leaves. If using the fresh fruit or leaves, use up to 2 cups of either into the same amount of water. Simmer at low to medium heat for 10 minutes with the lid left on. Remove from heat and steep for 10 minutes. Strain and enjoy warm or hot.
Bitter Melon Dosage and Warnings
There are no established guidelines for a correct dosage of bitter melon. (20) Bitter melon supplements are often found to contain extracts of the fruit in a dosage of up to 500 mg. Some supplements also provide guaranteed bitter principles, which is the chemical extract of the fruit that is responsible for the astringent taste and potential medicinal benefits. Powdered or extracted stems and leaves of the bitter melon plant may also be found in supplements, but the dosage amount can vary. Similar to the fruit, there are no known established guidelines for dosage.
Research has found that adverse effects of bitter melon can include convulsions in children, reduced fertility, an increase in menstrual flow, abdominal pain, diarrhea, headache, and increased liver function. Pregnant women and breastfeeding women should not use bitter melon. Children should not be given the seeds, juice or tea.
There are no known interactions between bitter melon and other plants or medications. Always consult a primary care physician before starting any supplement regimen. Discontinue use and consult a healthcare professional if any adverse reactions occur.
Consider Starting a Bitter Melon Regimen
Bitter melon offers a challenging taste and many potential benefits that may offer support as an alternative or complementary therapy. When using plants as a medicinal aid, a supplement or tea may provide the optimal form of delivery when compared to using the whole fruit.
Bitter melon has been a popular fruit in the tropics for centuries. It is suggested to have many medicinal uses. As the research shows, some of these uses may be worth exploring. Discover bitter melon supplements for yourself and see if they make a difference in your life.