Articles

According to Wikipedia where information is made available for all under the GNU General Public License term of use, Momordica charantia is a tropical and subtropical vine of the family Cucurbitaceae, widely grown for edible fruit, which is among the most bitter of all vegetables. English names for the plant and its fruit include bitter melon or bitter gourd (Chinese: 苦瓜; pinyin: kǔguā), hAgala kAyi (from Kannada), karaila (from Urdu & Hindi), pavakkya (from Malayalam), kaKara kaya (from Telugu) , parikkai (from Tamil), hanzal (from Arabic), ampalaya (from Tagalog). I would like to add that in Malaysia, it is locally known as Peria Katak. The original home of the species is not known, other than that it is a native of the tropics. It is widely grown in India, South Asia, The Philippines, Southeast Asia, China, Africa and the Caribbean.

This herbaceous, tendril-bearing vine grows to 5 m. It bears simple, alternate leaves 4-12 cm across, with 3-7 deeply separated lobes. Each plant bears separate yellow male and female flowers. The fruit has a distinct warty looking exterior and an oblong shape. It is hollow in cross-section, with a relatively thin layer of flesh surrounding a central seed cavity filled with large flat seeds and pith. Seeds and pith appear white in unripe fruits, ripening to red; they are intensely bitter and must be removed before cooking. The flesh is crunchy and watery in texture, similar to cucumber, chayote or green bell pepper. The skin is tender and edible. The fruit is most often eaten green. Although it can also be eaten when it has started to ripen and turn yellowish, it becomes bitterer as it ripens. The fully ripe fruit turns orange and mushy, is too bitter to eat, and splits into segments which curl back dramatically to expose seeds covered in bright red pulp. Bitter melon comes in a variety of shapes and sizes. The typical Chinese phenotype is 20 to 30 cm long, oblong with bluntly tapering ends and pale green in colour, with a gently undulating, warty surface. The bitter melon more typical of India has a narrower shape with pointed ends, and a surface covered with jagged, triangular "teeth" and ridges. Coloration is green or white. Between these two extremes are any numbers of intermediate forms. Some bear miniature fruit of only 6 - 10 cm in length, which may be served individually as stuffed vegetables. These miniature fruit are popular in Southeast Asia as well as India.

Bitter melons have been used in various Asian traditional medicine systems for a long time. Like most bitter-tasting foods, bitter melon stimulates digestion. While this can be helpful in people with sluggish digestion, dyspepsia, and constipation, it can sometimes make heartburn and ulcers worse. The fact that bitter melon is also a demulcent and at least mild inflammation modulator, however, means that it rarely does have these negative effects, based on clinical experience and traditional reports.

Perhaps the best substantiated use to date is that of bitter melon for people with diabetes mellitus. Several preliminary (non-randomized, non-blinded) clinical trials suggest this benefit, though controlled trials are necessary for confirmation. In the Philippines, bitter melon tea is used in blood sugar control for poor people as exemplified in the very successful Operation Diabetes. For a detailed review of studies involving bitter melon and diabetes, see Abascal and Yarnell 2005.

In ayurvedic medicine, bitter melon is popularly seen as a "plant-insulin." It has been demonstrated that bitter melon contains a protein similar to bovine insulin, sometimes referred to as p-insulin or polypeptide-p (Baldwa, et al. 1977). When purified and injected subcutaneously into patients with insulin-dependent diabetes mellitus (IDDM), it acted very similar to slow-acting animal insulin and was able to sustain patients. One child in this small study who previously had many side effects from bovine insulin was able to use p-insulin exclusively for 5 months with no sign of problems. This represents the potential for a vegetarian alternative to animal insulin for patients with IDDM, as well as a potentially more sustainable source of insulin, and should be further developed. It is not possible to substitute eating bitter melon for taking insulin.

Though it has been claimed that bitter melon’s bitterness comes from quinine, no evidence could be located supporting this claim. Bitter melon is traditionally regarded by Asians, as well as Panamanians and Colombians, as useful for preventing and treating malaria. Laboratory studies have confirmed that various species of bitter melon have anti-malarial activity, though human studies have not yet been published.

Laboratory tests suggest that compounds in bitter melon might be effective for treating HIV infection. As most compounds isolated from bitter melon that impact HIV have either been proteins or glycoproteins (lectins), neither of which are well-absorbed, it is unlikely that oral intake of bitter melon will slow HIV in infected people. It is possible oral ingestion of bitter melon could offset negative effects of anti-HIV drugs, if a test tube study can be shown to be true in people. In one preliminary clinical trial, an enema form of a bitter melon extract showed some benefits in people infected with HIV (Zhang 1992). Clearly more research is necessary before this could be recommended.

The other realm showing the most promise related to bitter melon is as an immunomodulator. One clinical trial found very limited evidence that bitter melon might improve immune cell function in people with cancer, but this needs to be verified and amplified in other research. If proven correct this is another way bitter melon could help people infected with HIV.