On The Shelf
Mickie Cathers
Bitter melon dietary supplements are advertised as supporting healthy digestion and promoting increased metabolism and decreased body weight by balancing blood glucose levels. While consumers use bitter melon to lower cholesterol, evidence supporting this use is lacking.
Background
Bitter melon is a climbing shrub that grows mainly in Asian countries as well as tropical areas such as the Amazon, East Africa, and the Caribbean. The green fruit resembles a warty cucumber and is known to be very bitter, though it is frequently used in cooking and as a traditional medicinal treatment for diabetes and various other conditions in Bangladesh and other countries in Asia.
Bitter melon seeds, leaves, berries, and fruit peels are rich in vitamins A, B1, B2, B9, C, and E and minerals such as calcium, potassium, zinc, magnesium, phosphorus, and iron. It has many bioactive substances, including anthraquinones, saponin, triterpenes, alkaloids, and momordicine. The plant and fruit extracts include isolated compounds such as charantin, insulin-like peptide, and alkaloid-like extracts that possess hypoglycemic properties. Due to the abundance of antioxidants, bitter melon is thought to have anti-inflammatory properties, potential antibacterial and antiviral activities, and anticancer effects.
Is there a benefit?
Bitter melon has been extensively studied for its medicinal effects in treating many conditions including diabetes, obesity, dyslipidemia, and certain cancers.
In vitro and animal studies suggest that bitter melon extract is a potent inhibitor of lipogenesis and stimulator of lipolysis activity and may be an effective therapy to reduce adipogenesis in humans. However, there are few clinical trials evaluating bitter melon in human studies and meta-analysis reviews reveal that these studies have small sample sizes and poor study designs.
One study, a 12-week randomized, placebo-controlled clinical study on 76 prediabetic patients was published in the April 2023 issue of Food Science and Biotechnology. Kim and colleagues investigated the effects of 2.4 g/day of bitter melon extract on glucose metabolism, insulin resistance, and various metabolic parameters of the participants. Results revealed that glucose levels decreased in the bitter melon extract group after 12 weeks of supplementation compared with the placebo group. Their results suggested that bitter melon may lower glucose levels due to glucagon suppression in patients with prediabetes.
Dosage and availability
Bitter melon is available online and in health food and grocery stores as a liquid, capsules, caplets, and as a powder to mix into beverages. Dosages of available products range from 1,000 mg to 15,000 mg per serving while the typical recommended dose is 500 mg to 1,000 mg taken 2 to 3 times daily.
What to tell your patients
Generally considered safe, bitter melon supplementation is not approved or regulated by FDA, and there isn’t enough reliable evidence to support its use. Bitter melon extracts are usually well tolerated, and although adverse effects are uncommon, they can include abdominal discomfort, heartburn, constipation or diarrhea, nausea and vomiting, dizziness, headache, and hypoglycemia. Counsel patients taking diabetes medication to monitor their blood glucose carefully as bitter melon may lower blood glucose levels. Bitter melon should not be used during pregnancy as it is a potential abortifacient. ■