Overview

• The University of Portsmouth-led study tested 32 healthy adults who rinsed for one minute with apple juice and then with local tap water.
• After apple juice, saliva’s lubricating function dipped but largely recovered within about 10 minutes, with mucin proteins remaining stable.
• Portsmouth tap water produced a stronger immediate rise in friction than the juice, a result linked to high sodium, potassium and magnesium levels, though recovery was quicker.
• Protein analyses showed significant decreases in immunoglobulins, cystatins and carbonic anhydrase following apple juice exposure, indicating short-term shifts in oral defense components.
• Researchers plan follow-up work on repeated exposures, direct effects on teeth, deionized water comparisons and the feasibility of adding protective proteins to drinks or oral-care products.