BITTER GOURD HEALTH BENEFITS
by Dr. Sandra Habicht
Bitter gourd is a functional vegetable with beneficial effects on health
Bitter gourd is a popular vegetable in some Asian countries, where the health benefits of the plant are well-known—particularly, its ability to lower blood glucose in diabetics. Bitter gourd has been used to treat diabetes in traditional medicine and is now commercially available as tea (from fruits or leaves), juice, extracts, and pills. Although these products promise health benefits, most of the manufacturers do not offer scientifically proven data on the effectiveness of bitter gourd or their products. However, in recent years researchers worldwide have started to focus on the antidiabetic effects of bitter gourd. The goal is to provide safe and clear preparation and dosage recommendations so that consumers will realize the greatest benefit from consuming fresh bitter gourd or bitter gourd products.
It is scientifically proven: bitter gourd lowers blood glucose levels!
Bitter gourd treatments of cell cultures or feeding trials with laboratory animals such as mice or rats show bitter gourd does have blood glucose lowering properties. Bitter gourd is not like most medicinal drugs, which are effective only in one target organ or tissue; rather, it influences glucose metabolism all over the body.
Bitter gourd lowers dietary carbohydrate digestion
The glucose metabolism starts in the gut. Carbohydrates and sugars are metabolized to glucose (one type of sugar) before glucose is transported from the gut to the blood. Bitter gourd reduces the amount of glucose that is released into the blood by inhibiting the enzymes that break down disaccharides to two monosaccharides (e.g. glucose) (Oishi et al. 2007, Kumar Shetty et al. 2005). Bitter gourd can influence the transport channels for glucose, which also reduces glucose transport into the blood (Singh et al. 2004). This effect is important for the treatment of both Type I and Type II diabetic patients and helps to prevent high blood sugar levels after meals.
Bitter gourd plant insulin discovered
The pancreas reacts to increasing blood sugar levels by secreting insulin into the blood. Insulin helps to transport the sugar from the blood to the skeletal muscle and the fat tissue where it is used to produce energy. Insulin will also stop the liver to produce sugar from glycogen storages and to release the sugar into the blood.
Thus, insulin is necessary to lower high blood sugar levels. In Type I diabetes, also called insulin-dependent diabetes, the pancreas does not produce or secrete enough insulin to keep blood sugar levels low. Bitter gourd has been shown to be effective in treating Type I diabetes in rats or mice by increasing pancreatic insulin secretion Yibchok-Anun et al. 2006, Fernandes et al. 2007). Additionally, scientists found an insulin-like molecule in bitter gourd (Khanna et al. 1981). Although bitter gourd may reduce the number of insulin injections required to manage Type 1 diabetes, it cannot replace insulin treatment completely or heal this form of the disease.
Bitter gourd reverses insulin resistance
Bitter gourd can play a role in the prevention and treatment of Type II diabetes, which is also called insulin-independent diabetes or adult onset diabetes. This form of the disease usually occurs in people who are overweight and inactive. In Type II diabetes, the liver, skeletal muscle, and fat tissues do not respond adequately to insulin—they are “insulin resistant.” Feeding trials with insulin resistant or Type II diabetic rats and mice have shown that bitter gourd helps to prevent or reverse insulin resistance (Nerurkar et al. 2008, Klomann et al. 2010). People with insulin resistance or those with a high risk of developing Type II diabetes have a good chance to prevent and treat the disease without drugs by increasing their physical activity and changing their diet.
Bitter gourd prevents diabetic complications
Chronically high sugar concentrations from Type I and Type II diabetes increase the risk of inflammation and oxidation in the whole body, leading to blindness, diabetic feet, kidney disease, stroke, or heart attack. Consuming bitter gourd can help prevent these complications, as it not only decreases blood sugar levels, but also has some antioxidative properties (Sathishsekar und Subramanian 2005, Klomann et al. 2010).
Bitter gourd can protect the body from other non-communicable diseases
Being overweight is one of the most important risk factors for diabetes and other diseases, and Type II diabetes is often accompanied by hypertension, high plasma cholesterol, or high plasma lipids. Together, these conditions increase the risk of stroke or heart attack. For overweight Type II diabetic patients, bitter gourd can help to improve health. In mice and rats, bitter gourd has been shown to reduce hypertension (Singh et al. 2004), plasma cholesterol (Nerurkar et al. 2008), and plasma lipids (Nerurkar et al. 2008). Apart from this, bitter gourd helps weight loss. There is also evidence that bitter gourd might be effective in cancer treatment.
More bitter gourd does not help more. Please be careful!
Exclusive consumption of bitter gourd, bitter gourd juice, or other bitter gourd products can lead to dangerous hypoglycemia when consumed by diabetic patients under oral drug treatment, in too high dosages, by children, or on a hungry stomach. Pregnant or breastfeeding woman should not consume bitter gourd or bitter gourd products. Although bitter gourd can help prevent insulin resistance or severe diabetic complications, it is important to consider situations in which bitter gourd may be harmful to your health.
Fernandes, NP., Lagishetty, CV., Panda, VS., Naik, SR.: An experimental evaluation of the antidiabetic and antlipidemic properties of a standardized Momordica charantia fruit extract. BMC Complement Altern Med 7(29). doi: 10.1186/1472-6882-7-29. 2007
Khanna, P., Jain, SC., Panagariya, A., Dixit, VP.: Hypoglycemic activity of polypeptide-p from a plant source. J Nat Prod 44(6). 648-655. 1981
Klomann, SD., Mueller, AS., Pallauf, J., Krawinkel, MB.: Antidiabetic effects of bitter gourd extracts in insulin resistant db/db mice. Br J Nutr, doi: 10.1017/S0007114510002680. 2010
Kumar Shetty, A., Suresh Kumar, G., Veerayya Salimath, P.: Bitter gourd (Momordica charantia) modulates activities of intestinal and renal disaccharidases in streptozotocin-induced diabetic rats. Mol Nutr Food Res 49(8). 791–796. 2005
Nerurkar, PV., Lee, YK., Motosue, M., Adeli, K., Nerurkar, VR.: Momordica charantia (bitter melon) reduces plasma apolipoprotein B-100 and inrcreases hepatic insulin receptor substrate and phosphoinositide-3 kinase interactions. Br J Nutr 100(4). 751-759. 2008
Oishi, Y., Sakamoto, T., Udagawa, H., Taniguchi, H., Kobayashi-Hattori, K., Ozawa, Y., Takita, T.: Inhibition of increases in blood glucose and serum neutral fat by Momordica charantia saponin fraction. Biosci Biotechnol Biochem 71(3). 735-740. 2007
Sathishsekar, D., Subramanian, S.: Beneficial effects of Momordica charantia seeds in the treatment of STZ-induced diabetes in experimental rats. Biol Pharm Bull 28(6). 978-983. 2005
Singh, J., Adeghate, E., Cummings, E., Giannikipolous, C., Sharma, AK., Ahmed, I.: Beneficial effects and mechanism of action of Momordica charantia juice in the treatment of streptozotocin-induced diabetes mellitus in rat. Mol Cell Biochem 261(1-2). 63-70. 2004
Yibchok-Anun, S., Adisakwattana, S., Yao, CY., Sangvanich, P., Roengsumran, S., Hsu, WH.: Slow acting protein extract from fruit pulp of Momordica charantia with insulin secretagogue and insulinomimetic activities. Biol Pharm Bull 29(6). 1126—1131. 2006