Effects of Sports Drink Consumption on Salivary pH During Exercise

Individuals who regularly exercise appear to be at higher risk for developing dental caries and erosion (1). Many believe the low pH of sports drinks (typically between 3 and 4) causes saliva pH decrease below 5.5, which results in dental erosion. However, beverage consumption during exercise can maintain hydration status and salivary flow rate which can help protect teeth. Purpose: To observe the effects of water and sports drink consumption on salivary pH during exercise in college-aged students.

Methods: Approval was obtained by the Institutional Review Board, and all participants signed an informed consent form prior to testing. Results were analyzed using SPSS. Ten healthy, recreationally active college students participated in three 30 minute exercise sessions on separate days. Specific gravity was measured before each exercise session using a refractometer to ensure participants were adequately hydrated. Exercise sessions consisted of cycling on an ergometer at 70%-85% of the participant's maximal heart rate. Participants were randomly assigned to one of three treatments (no beverage, water, or Gatorade) and consumed 80 mL of their designated drink every 10 minutes during the continuous exercise session. Beverage consumption occurred after 5, 15, and 25 minutes, and saliva pH was tested occurred after 0, 10, 20, 30 minutes, and 10 minutes post-exercise using Hydrion^TM Urine and Saliva pH paper.

Results: Saliva pH increased by 0.165 with no beverage consumption, decreased by 0.08 with the water treatment, and decreased by 0.26 with the Gatorade treatment. None of the treatment groups were significantly different after the 30 minute exercise session (two-way ANOVA, p=0.057). However, initial pH values were different from each other among the three treatments, so saliva pH was standardized by converting pH to change scores. The change score of Gatorade was significantly different from the control at the end of the exercise session (post-hoc LSD, p=0.018).

Conclusions: Saliva pH never dropped below the critical value of 5.5, indicating a minimal risk for erosion. Sports drinks can help maintain adequate hydration status, which can increase saliva output and oral buffering capacity, perhaps minimizing saliva pH change. Exercise or hydration status may change the composition of saliva, and method of saliva collection may yield different results.

Resources

Charlie Wenner presenting at the Northland Chapter of the American College of Sports Medicine April 29, 2016, at the College of Saint Catherine, St. Paul, MN

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Effects of Sports Drink Consumption on Salivary pH During Exercise