The pH scale measures the acidity or basicity of aqueous solutions, which includes all beverages. This scale ranges from 0 to 14, where a value of 7 is considered chemically neutral, like pure water. Drinks with a pH below 7 are acidic, while those with a pH greater than 7 are defined as basic or alkaline.
Defining Alkalinity in Beverages
The pH scale is logarithmic, meaning each whole number change represents a tenfold difference in hydrogen ion concentration. For example, a drink with a pH of 8 is ten times more basic than one with a pH of 7. The basic nature of a beverage is determined by the concentration of hydroxyl ions (OH-) relative to hydrogen ions (H+). When hydroxyl ions are more abundant, the solution is basic.
The alkalinity of a beverage is often conferred by mineral salts, such as bicarbonate, carbonate, and calcium, which act as buffers to resist changes in acidity. These compounds allow the liquid to neutralize a certain amount of acid without its pH dropping significantly. Common tap water typically falls within a broad pH range of 6.5 to 8.5, though it is usually close to neutral. Specialized alkaline products are manufactured to maximize this buffering capacity and achieve a higher pH number.
Common Examples of Basic Drinks
The most widely known example of a basic beverage is commercially marketed alkaline water, which is often chemically processed to achieve a pH between 8 and 10. Manufacturers typically use a process called ionization or add alkaline-forming compounds like magnesium, calcium, or bicarbonate to increase the final pH. Some natural spring waters can also be naturally alkaline, depending on the mineral composition of the rock layers the water flows through.
Certain plant-based beverages and teas can also exhibit a neutral to slightly basic pH profile. Unsweetened almond milk, for instance, generally falls within a pH range that can extend slightly above 7. Herbal infusions, such as some varieties of green or chamomile tea, may also have a pH that is close to or slightly above neutral, depending on the brewing time and water source.
Health Claims Associated with Alkaline Consumption
The interest in basic drinks stems from the alkaline diet hypothesis, which suggests that consuming alkaline foods and liquids can influence the body’s internal chemistry. Proponents of this diet claim that a modern diet rich in meat, dairy, and processed sugar creates an acidic environment in the body. They believe this state is linked to various chronic health issues and that alkaline drinks can help neutralize this alleged excess acidity.
Claims regarding detoxification or slowing down the aging process lack consistent scientific support. A more targeted application is the temporary relief of acid reflux, or gastroesophageal reflux disease (GERD). A basic liquid can briefly neutralize the highly acidic stomach contents, providing a short-term reduction in symptoms. This localized effect, however, does not translate into a systemic change in the body’s overall acid-base balance.
How the Body Regulates Internal pH
The body possesses multiple, highly efficient systems to maintain the pH of the blood within a narrow, slightly alkaline range of 7.35 to 7.45. This process, known as homeostasis, is robustly protected because a shift outside this range can be life-threatening. The primary defense mechanism involves chemical buffer systems, such as the bicarbonate buffer, which instantly guard against major pH fluctuations.
The respiratory system provides rapid regulation by controlling the exhalation of carbon dioxide, which forms carbonic acid in the blood. The kidneys offer a slower but more powerful long-term control mechanism by excreting excess hydrogen ions and reabsorbing bicarbonate ions into the bloodstream. When a basic drink is consumed, it first encounters the stomach’s hydrochloric acid, which has a pH between 1.5 and 3.5. This extremely acidic environment instantly neutralizes the alkaline liquid, ensuring that the beverage has a negligible impact on the body’s systemic blood pH.