Does Drinking Caffeinated Soft-Drink Cause Short-Term Oral Dryness?

Objectives: Caffeine's psychoactive properties distinguish it as the most-widely consumed stimulant in the world. It may also contribute to dehydration in the consumer, which decreases salivary flow. Since saliva plays many important roles in maintaining oral heath, the aim of this study was to assess whether caffeine containing soft-drinks may be destructive of the dentition by increasing oral dryness. This study measured the saliva production of healthy individuals following caffeine consumption.

Methods: Saliva was collected from 35 subjects at baseline and 1-hour after drinking either caffeinated or decaffeinated Mountain Dew. Subjects repeated this procedure on a different day for the alternate beverage. Each saliva collection included: 15-minute unstimulated whole saliva, 5-minute paraffin-stimulated whole saliva, and 3x10-second minor gland secretion. We collected whole saliva in cups and minor gland secretion with Sialopaper strips on the labial mucosa. Volume was inferred using cup weight and a calibrated Periotron, respectively. Results were analyzed with a 2-period 2 treatment cross-over trial using the two-stage Grizzle model.

Results: Salivary flow-rates (mean±SD) are shown in the Table. Caffeine consumption had no significant effect on flow-rate. Unstimulated and stimulated flow-rates increased regardless of caffeine content. Minor gland output decreased after both beverages.

FLOW-RATE	CAFFEINE			DECAF
	Baseline	After	Δ	Baseline	After	Δ
Unstimulated(mL/min)	0.34±0.21	0.45±0.21	0.10±0.14	0.38±0.21	0.42±0.23	0.05±0.13
Stimulated(mL/min)	1.35±0.63	1.51±0.69	0.16±0.37	1.41±0.66	1.42±0.62	0.01±0.44
Minor(uL/min)	2.71±0.97	2.55±1.15	-0.15±0.70	2.74±1.14	2.47±0.87	-0.27±0.73

Conclusions: Short-term oral dryness may not influence repeated consumption of caffeinated soft-drinks by consumers. Any potential diuretic effects of caffeine were not reflected in salivary flow. 

Supported by a faculty start-up fund and the UMSOD Summer Fellowship program