Bitter Melon: Sweet Reward for Diabetes?

Bitter melon is a plant that grows in regions of Asia, South America, East Africa, and the Caribbean. The fruit has been used, by natives, throughout time as food and in medicine to treat diabetes, cancer, viral infections, and immune disorders. The active ingredients in bitter melon have been extensively studied for the fruit’s blood glucose lowering properties.

Currently, there are 150 million people with diabetes worldwide, and this figure is expected to increase to over 300 million by 2025. For many people living with diabetes is a constant struggle. Checking their blood glucose levels, watching what they eat and taking medications doesn’t always mean that their diabetes is under control. A national survey conducted in 2007 found that 17.7 percent of American adults had used dietary supplements, other than vitamins and minerals, in the past 12 months for a health condition. With 18.8 million people in the United States diagnosed with type-2 diabetes some may look to the Internet for information and stumble upon bitter melon.

What is the Consumer Finding?
Patients are more proactive about their health in this new age. Unfortunately there is just as much inaccurate, or unsubstantiated, medical information on the Internet as there is accurate information. Homeopathic websites refer to bitter melon as “a natural remedy for type-2 diabetes” and “an alternative to insulin” yet provide little evidence supporting these bold statements. Top selling herbal supplement brands have websites that market bitter melon in a number of ways that could seem appealing for diabetics who are struggle with their blood glucose control. Some statements include:

• “Bitter Melon, also known as Bitter Gourd, has been traditionally used to regulate blood sugar levels within the normal limits. It contains Gurmarin, a polypeptide that has been shown in experimental studies to achieve its regulating effect by suppressing the neural response to sweet taste stimuli. Bitter Melon is also a natural source of Vitamin C.”
• “Bitter Melon, also known as Bitter Gourd, has been used to support already normal blood sugar levels and has been shown in experimental studies to achieve a regulating effect by suppressing the neural response to sweet taste stimuli. (These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure or prevent any disease)”

What Does the Research Show? 

Scientists in India began studying bitter melon’s effects on blood glucose in the 1950s, and their work has lead to other researcher’s interest in investigating the fruit’s potential for blood glucose management for those with diabetes. Throughout the past sixty years, studies reveal varying evidence to support the effectiveness of bitter melon for diabetes.

The largest study to evaluate the blood glucose-lowering effect of bitter melon was published in 1999 in the Bangladesh Medical Research Council Bulletin. The clinical trial examined the effect of the fruit on 100 patients with type-2 diabetes. The researchers recorded the patients’ blood glucose levels both without food intake for 12-24 hours and after taking 75g of glucose. They then administered a bitter melon pulp suspension to the diabetic patients and the results revealed a significant 14% reduction in fasting and post-meal serum glucose levels.

In another study researchers examined whether adding bitter melon capsules to the 40 participants existing medication could decrease their hemoglobin A1c levels by 1%. The results revealed only a 0.217% decline in the experimental group. The authors relied on the subjects to administer the supplements themselves and did not state the dosage used. The researchers stated that bitter melon’s effectiveness is undetermined.

A 2008 study, published in Chemistry and Biology, isolated four compounds in bitter melon that activate an enzyme that is responsible for regulating metabolism and transporting glucose from the blood into the cells. The researchers touted that isolating these compounds could lead to medications that someday could control obesity and type-2 diabetes.

Should You Recommend Bitter Melon to Patients? 

Personally, I would not recommend such a supplement to my patients. Not because there is limited scientific evidence on it, but because sometimes it has the potential to work too well. If taken incorrectly blood sugar can drop to unsafe levels. Often, in the case of supplements, dosage can be vague or worse—consumers can view it as safe at any dose because it is natural. The herbal supplement industry is loosely regulated and potency may differ between products.

One potential side effect is hypoglycemia, which can be fatal for diabetics. Hypoglycemia, a condition in which blood sugar drops too low, is the primary risk involved in taking bitter melon. If hypoglycemia is not treated quickly, the diabetic patient could fall into a coma that may result in death. 

With over 60 years of research bitter melon still lacks enough evidence for health care professionals to start recommending it for diabetes management. Many homeopathic websites justify the use of supplements by noting that several conventional medications used today came from natural substances. The difference is that conventional medications go through rigorous human testing before they hit the market. Make sure to always take in to consideration the cost, safety and effectiveness of supplements before recommending them to your patients.