Why Propolis Matters More Than We Thought

A new study from the Czech Academy of Sciences has uncovered a remarkable secret about propolis—the resinous substance bees use to coat and protect their hives. Beyond its well-known antibacterial and antiviral properties, propolis also acts as a nutritional powerhouse, enriching both honey and stored sugar syrup with vital compounds that help keep bees healthy and resilient.

What Is p-Coumaric Acid and Why Do Bees Need It?

At the heart of this discovery is p-coumaric acid, a plant-derived phenolic compound known for its antioxidant and immune-boosting effects. In honey bees, p-coumaric acid helps:

• Strengthen detoxification pathways
• Enhance immunity and stress resistance
• Extend lifespan and improve colony resilience

Until now, it was thought that p-coumaric acid came only from pollen and honey, and that feeding bees artificial syrups might deprive them of this essential nutrient.

The Big Discovery: Propolis Enriches Stored Food

The researchers fed colonies sucrose syrup—commonly used by beekeepers as a winter feed—and later analysed it using HPLC-HRMS (high-resolution mass spectrometry). Fresh syrup contained no detectable p-coumaric acid. Yet, after bees stored it in capped combs, its chemical profile changed dramatically:

Sucrose syrup stored in the hive contained the same or higher levels of p-coumaric acid as natural honey.

The reason lies in the propolis-rich combs. Propolis gradually releases p-coumaric acid and other beneficial phytochemicals into nearby honey and syrup stores.

Dark Combs, Rich Nutrition

Another fascinating finding was that darker combs—those with thicker propolis coatings—contained more p-coumaric acid than lighter ones. When researchers removed the propolis layer, p-coumaric acid levels dropped sharply. This confirms that propolis is the primary source of these vital nutrients within the hive.

What This Means for Beekeepers

This study overturns a long-standing concern in beekeeping: that feeding bees sugar syrup during dearth periods deprives them of key phytochemicals. On the contrary, once the syrup is stored in the comb, it becomes naturally enriched with p-coumaric acid from propolis, providing similar nutritional benefits to honey.

For beekeepers, this highlights the importance of:

• Maintaining healthy, propolis-rich colonies
• Avoiding excessive scraping or replacing of old combs
• Encouraging natural propolising behaviour for improved colony health

Beyond the Hive: Benefits for Humans

Interestingly, p-coumaric acid isn’t just good for bees. It has been widely studied for its antioxidant, anti-inflammatory, and anticancer properties in humans, contributing to the potential health benefits of honey and propolis-based products.

Key Takeaway

“Propolis is more than a hive disinfectant—it’s a silent partner in bee nutrition.”

By enriching honey and even stored sugar syrup with bioactive compounds, propolis ensures that bees retain access to crucial nutrients throughout the year. This new understanding reinforces the role of propolis as an essential component of colony health, bridging the gap between natural and supplementary feeding practices.