OTHER NAMES
• Jambul, Jamun Beej • Java Plum
• Rose Apple
Eugenia jambolana or
Syzygium cumini
The jambolan tree is native to India, Sri Lanka, and parts of Southeast Asia, and it now grows in South America and Florida. It grows to a height of 50–100 feet and produces edible, berry-like fruit. The fruit is about the size of a cherry and tastes somewhat acidic, although the white berry is said to taste sweeter. It is highly consumed as a tea in Brazil, but the fruit has also been used as a jelly or jam. The seed and bark are being studied in animals for glucose-and cholesterol-lowering effects.
USES
Jambolan is included in multi-ingredient dietary supplements used to treat diabetes. There is no evidence that jambolan is beneficial to people with diabetes. However, jambolan may be safely eaten as a food.
DOSE
Jambolan is not widely used in the United States, although in other countries the leaves are prepared as a tea and used by people with diabetes. The tea and a crushed powder form have been used in clinical studies. Jambolan can sometimes be found multi-ingredient dietary supplements in pill form. There is no recommended dose.
STUDIES
The two studies of jambolan and diabetes are small and have conflicting results.
• In one study with poor design, 30 patients with type 2 diabetes were given 4 grams (g) crushed jambolan powder three times a day for 3 months. The patients were com pared to six patients on 250 milligrams (mg) daily of a sulfonylurea (a class of diabetes medication). Fasting blood glucose decreased significantly by 52 mg/dl after 2 months in the jambolan group, but the decrease was not significant at 3 months. However, another measure of blood glucose called an oral glucose tolerance test was significantly lower than baseline both at 2 and 3 months.
• A separate, well-designed study (randomized, double- blind, placebo-controlled) compared three groups of patients. Twenty-seven patients were randomized to the groups after a 3-month run-in period (where no treatment is given) and followed for 28 days. One group received jambolan tea plus a placebo (dummy pills) twice daily, the other group received a placebo tea plus the diabetes medication glyburide (a sulfonylurea), and the last group received a placebo tea and placebo tablets twice daily. Patients were asked to drink the tea (placebo or 2 g daily dry leaf in a teabag steeped for 5 minutes in 1 liter of water) as a water substitute. Fasting glucose increased significantly from 157 to 164 milligrams/deciliter (mg/dl) at 28 days in the jambolan group. In contrast, fasting glucose decreased from 158 to 122 mg/dl in the glyburide group.
SIDE EFFECTS AND DRUG INTERACTIONS
No one taking jambolan has reported side effects or drug interactions. However, patients should monitor their blood glucose closely when taking jambolan. If you are taking or are considering taking jambolan, talk to your health care provider.