FACT CHECK: Can consuming jamun seeds lower your blood sugar spike?

CLAIM:

Consuming powdered jamun seeds can naturally lower blood sugar spikes and help manage diabetes. The reel claims that jamun seeds contain a compound called “jaboline” and are rich in polyphenols, making them beneficial for people with diabetes. It suggests drying the seeds and grinding them into a powder for consumption.

FACT:

Jamun seeds contain bioactive compounds and a few small studies suggest they may help improve blood sugar control in people with type 2 diabetes. However, the evidence remains limited and inconsistent, with no large, high-quality clinical trials proving that consuming jamun seed powder can reliably or naturally lower blood sugar spikes. Experts advise that it should not be used as a substitute for proven diabetes treatments and caution against exaggerated claims surrounding commercial supplements. 

In a recent Instagram reel posted by Nutritionist Khushi Chhabra, who has 1.53 lakh followers on Instagram, claims have been made about the potential benefits of jamun seeds for blood sugar control. The reel, which has garnered 23.9k views, suggests that instead of discarding the seeds after eating jamun, they can be dried and ground into a powder to help manage diabetes.

In the video, Chhabra explains that jamun seeds contain a compound called “jaboline” and are rich in polyphenols, which she says can “naturally lower your blood sugar spike” and are “great for diabetics.” She advises viewers: “Don't throw away the seeds because consuming jamun seeds can naturally lower your blood sugar spike and is great for diabetics because jamun seeds contain a compound called jaboline which naturally lowers your blood sugar spike and is rich in polyphenols which help in managing diabetes. All you need to do is eat your jamun, don't throw away the seeds, dry it for 24 hours and grind it into a powder.”

The claim has prompted interest among viewers, raising questions about whether consuming jamun seed powder can indeed help regulate blood sugar levels and whether scientific evidence supports these purported benefits.

Do jamun seeds help control blood sugar levels? 

Available evidence suggests that jamun seeds contain bioactive compounds that may have glucose-lowering properties, and some small human studies have reported improvements in blood sugar control. However, results have not been consistent across studies, and the current evidence is insufficient to conclude that consuming jamun seed powder can reliably or “naturally” lower blood sugar spikes. Larger, well-designed clinical trials are required to establish its effectiveness and safety.

An earlier 2006 trial evaluated tea prepared from S. cumini leaves in patients with type 2 diabetes and compared it with glyburide, a commonly prescribed antidiabetic drug. The researchers found that while fasting blood glucose levels “decreased significantly with glyburide,” they “did not change with S. cumini tea or placebo.” Other parameters, including cholesterol levels, body mass index and markers of liver and kidney function, also showed no significant differences between the groups. The findings suggested that the plant preparation tested did not exhibit a measurable glucose-lowering effect over the 28-day study period.

However, subsequent studies have reported more encouraging results. A 2015 study involving 30 people aged 51–60 years with type 2 diabetes examined the effects of taking 2 g of jamun seed powder daily for 60 days. The researchers found that fasting blood glucose levels decreased significantly after 30 days and declined further by the end of the study. They also observed a reduction in postprandial (after-meal) blood glucose levels, while no similar changes were seen in the control group.

These findings indicated that regular supplementation with jamun seed powder was associated with improved blood sugar control among the participants studied.

Similar findings were reported in a larger double-blind, randomised controlled trial published in 2017. The study enrolled 99 patients with poorly controlled type 2 diabetes, with one group receiving 10 g of jamun seed powder daily while continuing their routine oral hypoglycemic medications, and the other receiving a placebo. Over 90 days, fasting plasma glucose levels in the intervention group fell by 30%, while HbA1c levels also declined significantly. The authors concluded that “supplementation with jamun seed powder improves glycemic control significantly in type 2 DM with poorly controlled glycemic levels on diet and OHA.” However, they cautioned that “before recommendation, multicentric trial with larger sample size, dose, and duration should be planned,” indicating that the evidence remains preliminary.

More recently, a 2022 review highlighted that jamun seeds are rich in carbohydrates, proteins, lipids, vitamins and minerals and possess several bioactive compounds that have attracted interest for their potential role in functional foods. The review noted that studies have explored the use of jamun seed powder in bakery products and therapeutic foods and stated that jamun seeds “could also be exploited for designing foods for patients with diabetes due to presence of high jamboline.” At the same time, the authors emphasised that “future studies are required to evaluate the bioavailability and safety of bioactive compounds from JS,” and that extensive research is still needed before such applications can be recommended.

Adding to this body of evidence, a 2025 study examined the effects of a low-calorie jamun beverage in streptozotocin-induced diabetic rats. Researchers found that blood glucose levels decreased significantly in animals receiving the drink and that no adverse effects were observed in kidney or pancreatic tissues. They concluded that the beverage showed “significant potential for managing diabetes mellitus” and that its benefits were likely related to the fruit’s anti-inflammatory and antioxidant compounds. Nevertheless, the authors stressed that the findings were limited to an animal model and that “clinical trials are needed to validate these findings in humans.”

Do experts agree?

Dr Rajiv Kovil, Head of Diabetology and Weight Loss Expert at Zandra Healthcare, said that jamun and its seeds have been used in traditional Indian medicine for generations and continue to be popular among people with diabetes. He noted that the fruit, often referred to as Indian blackberry, is rich in fibre, antioxidants and vitamins and has a low glycaemic index, which may help produce a smaller rise in blood sugar compared with sweeter fruits.

“Traditionally, we have seen that they have a very low glycaemic index. Because of the fibre, these fruits are going to give you a lesser glycaemic spike. They are also rich in fibre and contain a good amount of antioxidants,” he said.

However, Dr Kovil emphasised that the scientific evidence supporting the use of jamun seeds for diabetes control remains limited. According to him, only a handful of human studies have been conducted, and these are preliminary in nature.

“There are very, very few human studies, and they are also very preliminary. So, it cannot ever be used as a substitute for proven diabetes treatment. There is no large, high-quality clinical trial that has shown that it can improve blood sugar and control diabetes,” he said.

He further pointed out that several important aspects required to establish a therapeutic benefit, including optimal dosage, pharmacokinetics, pharmacodynamics, potency and side-effect profile, remain unknown.

“Just consuming jamun seed powder or tablets is a shot in the dark. There is no universally accepted dose, and there are no actual large clinical trials,” he said, cautioning people against exaggerated claims surrounding commercially available supplements. “People should be very cautious about claims such as reversing diabetes. Those claims take away from the real benefit - that jamun is a low-glycaemic-index, high-fibre fruit that can be part of a healthy diet.”

Adding to this, Dr Mahesh D M, Senior Consultant – Endocrinology, Aster CMI Hospital, Bengaluru, said that while some studies suggest jamun seeds may aid blood sugar management due to their polyphenols and antioxidant compounds, the benefits appear modest and require further confirmation in human trials.

“Jamun seed powder should not be considered a treatment or cure for diabetes, nor a replacement for prescribed medicines or insulin,” he said. He added that it may be used only as a dietary supplement alongside a healthy lifestyle and medical treatment.

Dr Mahesh also cautioned that people already taking antidiabetic medications or insulin should be careful while consuming jamun seed powder. “Since jamun seeds may have mild blood sugar-lowering effects, combining them with prescribed treatments could increase the risk of hypoglycaemia,” he said, noting that symptoms such as dizziness, sweating, weakness, confusion and shakiness may occur if blood sugar falls too low. Given the limited evidence on its interactions with diabetes medications, he advised people to monitor their blood sugar levels and consult their doctor before incorporating jamun seed powder into their routine. 

This story is done in collaboration with First Check, which is the health journalism vertical of DataLEADS