Contents
What it is
Bitter melon is the fruit of a climbing vine in the gourd family — cucumber-shaped but with a warty, ridged skin. It is native to India and Southeast Asia and is also grown in Okinawa and southern Korea. As the name says, it is intensely bitter, and that bitterness is the point of the ingredient. It is eaten unripe and green; scraping out the seeds and white pith and salting the slices takes a little of the edge off. It goes into stir-fries and dressed side dishes, and is dried for tea.
Scientific name Momordica charantia
Bitter melon earned the nickname "plant insulin" because of compounds such as charantin, polypeptide-p and vicine. Cell and animal experiments show them increasing glucose uptake.
Humans are the problem. A Cochrane review pooling randomised trials in type 2 diabetes concluded that evidence for glycaemic control is insufficient. This is an ingredient where expectation and evidence sit far apart, and that is worth knowing first.
Key benefits
- Not established
A plausible mechanism for blood sugar exists
Charantin and polypeptide-p have been observed promoting glucose transporter translocation. But human trials have not consistently shown clinically meaningful glucose lowering. It cannot replace diabetes medication.[1]
- Nutrition data
Very high in vitamin C
84 mg per 100 g, more than lemon, at just 17 kcal. This is why bitter melon is worth eating regardless of the blood sugar story.
- Nutrition data
Dense in fibre for the calories
2.8 g per 100 g. At 17 kcal that is a very high ratio, which helps with fullness.
- Nutrition data
Rich in folate
72 µg per 100 g puts it near the top among vegetables. Folate is needed for cell division and red blood cell formation.
How to eat it well
- To cut the bitterness, remove the seeds and white pith, then salt it and squeeze out the liquid.
- Slicing thin and soaking in cold water removes more bitterness — along with water-soluble compounds.
- Stir-frying with egg or tofu lets fat and protein temper the bitterness. Okinawan stir-fry works on this principle.
- Bitter melon tea loses most of its vitamin C in drying. Eating it fresh is nutritionally better.
- If your interest is blood sugar, eat it as food — but do not treat it as grounds for adjusting medication.
How to read the grades
Each benefit carries a label showing how far research on people supports it. Grades differ between items even within the same ingredient.
- Nutrition data
- A fact verifiable from food composition databases or health authorities. This is a different kind of statement from a clinical effect.
- Strong evidence
- Consistently confirmed across randomised controlled trials or meta-analyses.
- Moderate evidence
- Human studies exist, but effect sizes are small or results are mixed.
- Early research
- Cell or animal work, or small preliminary studies.
- Not established
- Commonly claimed, but not confirmed in studies on people.
What to watch out for
- Combined with diabetes medication, large amounts risk hypoglycaemia. If you take such drugs, monitor your glucose closely.
- Avoid it in pregnancy. The seeds and fruit contain compounds that may stimulate uterine contraction, and it has traditionally been contraindicated.
- The red aril around the seeds can cause vomiting and diarrhoea in children. Remove it.
- With G6PD deficiency, bitter melon seeds can trigger haemolysis.
- Concentrated bitter melon extracts have been linked to raised liver enzymes in some reports.
Nutrition
Approximate values per 100 g edible portion.
- Calories
- 17 kcal<1%
- Carbohydrates
- 3.7 g1%
- Fiber
- 2.8 g10%
- Protein
- 1.0 g2%
- Vitamin C
- 84 mg93%
- Folate
- 72 µg18%
- Potassium
- 296 mg6%
- Magnesium
- 17 mg4%
Percentages are of the US FDA Daily Value for adults and children 4 and over. National reference intakes differ by sex and age.
Calculate this alongside other ingredients →
Key nutrients
By health concern
Sources
The databases and health authorities this article's nutrition figures and health statements draw on.
