Bottled water is a convenient way to stay hydrated, especially when on-the-go. However, some people report that drinking bottled water makes their mouth feel dry. There are a few potential reasons for this:
Mineral Content
Most bottled waters contain some minerals like calcium, magnesium and sodium. While these minerals are beneficial in small amounts, higher concentrations can leave a drying effect in the mouth. This is especially true for bottled waters labeled as “mineral water.” The higher mineral content improves the taste but may cause dry mouth.
Purification Process
Purifying bottled water via distillation or reverse osmosis removes impurities but also strips out minerals that provide electrolytes. The lack of electrolytes can prevent proper hydration at a cellular level, causing dry mouth.
Acidity
Carbonated or seltzer waters tend to be more acidic (lower pH) than still bottled waters. Increased acidity can irritate salivary glands and leave the mouth feeling dry. The carbonation effect may also contribute to dry mouth.
Bottle Material
Some studies suggest chemicals may leach from plastic bottles into the water. These compounds like BPA and phthalates could potentially cause dry mouth. Using BPA-free plastic or glass bottles may help.
Dehydration
Ironically, drinking bottled water may not properly hydrate the body in some cases. Rapid drinking, inadequate amounts, and lack of electrolytes can actually lead to dehydration. This electrolyte imbalance can cause dry mouth.
While bottled water is generally safe, the unique processing and packaging may contribute to temporary dry mouth in some individuals. Sipping slowly, switching brands or bottle types, or adding electrolyte mixes can help provide proper hydration without an overly drying effect. As with any changes, consult your doctor if dry mouth persists.