Propolis for Cardiometabolic Health: What to Know

A recent study suggests that supplementation with propolis, also known as bee glue, may help reduce blood pressure and cholesterol levels. But is it safe and effective for everyone? An expert warns about the potential risks of this natural remedy.

Propolis, a brown and crumbly substance made by bees and used to build hives, had been used by the ancient Greeks, Romans, and Egyptians for its believed therapeutic properties.

People still commonly rely on propolis to help treat conditions like cold sores, genital herpes, and diabetes, although there isn't sufficient evidence to support these uses.

A recent meta-analysis of 22 randomized clinical trials sheds light on the potential benefits of propolis on cardiometabolic health. The study was published in the British Journal of Nutrition.

Improved cholesterol, triglycerides

The meta-analysis includes data from 1,164 adults who were either without known health conditions or had chronic diseases such as type 2 diabetes, metabolic syndrome, and polycystic ovary syndrome.

The daily dose of propolis tested in most trials ranged between 227 and 2,000 mg, and the interventions lasted from 4 to 48 weeks.

In these studies, propolis supplementation was associated with the following improvements:

• 10.4 mg/dL reduction in blood triglyceride levels, a type of fat in the blood. High levels of blood triglycerides are associated with an increased risk of heart disease.
• 2.2 mmHg decrease in systolic blood pressure, the top number in the blood pressure chart. Having high blood pressure, called hypertension, may lead to serious heart problems such as heart attack or stroke.
• 9.3 mg/dL decrease in LDL (the atherogenic) cholesterol. High LDL and LDL cholesterol levels are causal factors for developing fatty deposits in the blood vessels and, subsequently, cardiovascular disease.
• 7.3 mg/dL reduction in fasting blood glucose. When increased, it may help predict prediabetes, type 2 diabetes and metabolic syndrome.
• 0.4 reduction in the HOMA Insulin Resistance Index. Being insulin-resistant may raise blood sugar levels and lead to prediabetes and type 2 diabetes.

The authors concluded that propolis may lead to cardiometabolic improvement in adults but called for further studies to confirm the findings.

According to the findings of the present study, propolis intake can improve some cardiometabolic indices such as a significant reduction in the TAG, LDL-cholesterol, FBG, HbA1c, insulin, HOMA-IR and SBP. However, these effects were not clinically significant, meaning that propolis supplementation is unlikely to have a meaningful impact on an individual’s health.

Stronger evidence is needed, an expert says

Dr. Simin Liu, director of the Center for Global Cardiometabolic Health at Brown University, says the current evidence showing cardiometabolic benefits of propolis is still limited and largely based on small-scale or animal studies.

While propolis is generally well-tolerated, Liu warns that individuals should be mindful of potential risks, including allergic reactions, especially in individuals with bee product sensitivities. Furthermore, varying quality and composition across propolis products may impact efficacy and safety.

Large, high-quality, prospective cohorts with longer-term follow-up for clinical outcomes and rigorous intervention trials are needed before recommending routine supplementation.

Dr. Simin Liu

What could be other benefits of propolis?

Propolis is composed mainly of fatty acids, both saturated and unsaturated, flavonoids, and simple sugars. It also contains essential minerals such as calcium, magnesium, zinc, copper, and iron. These ingredients have well-established benefits on human health, but does it mean that propolis can be used to help treat a wide variety of health issues?

A 2021 meta-analysis of nine studies indicates that propolis may be superior in healing herpes simplex virus-induced sores than antiviral cream acyclovir.

However, many other human studies on propolis benefits are small, or the observed effects are insignificant.

According to a meta-analysis of 22 randomized clinical trials that included 1,082 participants, mostly with chronic health conditions, the use of propolis was associated with a 0.82 lb (0.37 kg) weight reduction and a 0.11 decrease in body mass index (BMI).

It’s noteworthy that the BMI result depended mostly on the data from one study, meaning that it may be too early to draw conclusions about propolis's effects on weight loss.

In a 2024 clinical trial, 94 adults with gingivitis (inflammation of the gums) and early-stage periodontitis took capsules either of propolis-mangosteen extract complex (PMEC) or placebo.

After eight weeks, individuals on PMEC saw better improvements in inflammatory biomarkers than those on placebo. However, there were no differences between clinical parameters such as gingivitis severity and bleeding on probing.

Supplementation with 50 mg propolis twice daily for four weeks versus placebo was tested in 54 male military cadets, according to a 2021 trial. The participants took tests to measure their aerobic and anaerobic performance.

Compared to placebo, propolis was associated with beneficial effects on inflammation and oxidative stress, which leads to cell damage after intense physical activity. However, the findings should not be generalized to the population because the study was small and conducted only in healthy males.

Women with type 2 diabetes who took 500 mg of propolis three times a day combined with exercise saw reductions in fasting blood glucose, insulin, and insulin resistance, according to a 2022 study.

However, type 2 diabetes is a complex and potentially life-threatening condition. Propolis or other supplements shouldn't replace prescribed medications and lifestyle changes.

The risks of allergy, harmful bacteria

In its natural state, propolis is about 5% pollen, which raises the risk of people with pollen allergies. It may also cause allergic reactions in people with allergies to bee products.

Propolis and other bee products may be contaminated with pyrrolizidine alkaloids (PAs), harmful substances classified as possibly carcinogenic to humans.

While bee products are known for their antimicrobial properties, harmful microorganisms like Escherichia coli and Clostridium botulinum can survive in them.

There isn't sufficient evidence of propolis' safety during pregnancy; therefore, pregnant individuals should avoid it.

Meanwhile, propolis taken by mouth while breastfeeding is likely safe, but daily doses shouldn't exceed 300 mg.

Propolis may interact with other medications, such as drugs changed by the liver (Cytochrome P450 1A2 (CYP1A2) substrates), medications that slow blood clotting (anticoagulant and antiplatelet drugs), and warfarin (Coumadin).

The takeaway

There's insufficient evidence to recommend propolis supplements to reduce cholesterol levels and blood pressure. In some individuals, propolis may cause allergic reactions and interact with prescription medications.