“Sugar makes wounds heal slower.”

The idea that sugar can slow wound healing likely stems from the well-understood negative impact of high blood sugar levels within the body, particularly in conditions like diabetes. When a person has uncontrolled diabetes, elevated glucose in the bloodstream can impair circulation, damage nerves, weaken the immune system, and increase inflammation, all of which significantly hinder the body's natural healing processes. It's a common misconception to extend this internal effect to the external application of sugar.

However, the truth is quite the opposite for topical application. Sugar has a long history in wound care, with evidence suggesting its use dating back to ancient Mesopotamian times, where honey and resins were applied to wounds (Review). More recently, finely powdered sugar was reported for wound cleaning in 1679, and modern medical practitioners in the 20th century, like Dr. Treacy O'Hanlon in the 1960s, successfully used granulated sugar on difficult-to-heal ulcers.

The scientific basis for sugar's effectiveness lies in its osmotic properties. When applied to a wound, sugar draws out excess moisture, or exudate, creating a dry environment that inhibits bacterial growth and reduces swelling. This reduction in water activity makes it difficult for bacteria to thrive. Additionally, sugar can help debride necrotic tissue, lower the wound's pH to an antibacterial level, and promote the formation of healthy granulation tissue, which is crucial for repair. It also attracts macrophages, cells vital for fighting infection and clearing debris. This creates a more favorable environment for the body's own healing mechanisms to take over, especially in infected wounds.