The pH scale measures how acidic or alkaline a substance is, based on its concentration of hydrogen ions. This scale ranges from 0 to 14, where a pH less than 7 indicates acidity, a pH greater than 7 indicates alkalinity (or basicity), and a pH of 7 is considered neutral. In various biological systems, pH plays a fundamental role in numerous physiological processes, influencing enzyme activity, nutrient absorption, and overall metabolic functions. Maintaining proper pH levels is therefore considered important for overall health.
Understanding pH and Its Role in the Body
The human body maintains specific pH levels across different areas to ensure proper functioning. For instance, blood pH is tightly regulated within a narrow range of 7.35 to 7.45. Deviations outside this range, such as dropping below 6.9, can lead to severe health consequences like a coma.
The body employs homeostatic mechanisms to preserve these pH balances. The lungs regulate carbon dioxide removal through breathing, which influences blood pH, while the kidneys excrete acids through urine. Chemical buffer systems, including proteins and phosphates, act as weak acids and bases to adjust the proportions of acids and bases in the body, regulating pH during minor physiological changes.
Different bodily fluids and organs have distinct pH levels tailored to their functions. The stomach, for example, maintains an acidic pH between 1.5 and 3.5, necessary for breaking down food and destroying pathogens. Conversely, enzymes in the small intestine require a more alkaline environment, with a pH ranging from 7.5 to 8.0, to function effectively. Skin also has a slightly acidic pH, between 4.7 and 5.7, which protects against microbes and maintains its barrier function.
Principles of pH Therapy
“pH therapy” refers to the concept of manipulating the body’s pH balance to address certain health issues or promote well-being. The underlying idea is that by adjusting the body’s acidity or alkalinity, one can create an environment more conducive to health or less favorable for disease. This approach often focuses on restoring what is perceived as an imbalanced pH.
The general goals of pH therapy involve encouraging a slightly more alkaline state in the body, particularly in the blood. Proponents believe that by shifting the body’s internal environment, they can optimize cellular function and support natural healing processes. This aims to achieve equilibrium or target specific acidic or alkaline environments within the body depending on the perceived health concern.
Common Applications of pH Therapy
pH therapy is explored in various contexts, from topical applications to dietary adjustments. In skincare, maintaining the skin’s slightly acidic pH, around 4.7 to 5.7, is beneficial for its barrier function and protection against microbes. Some skincare products are designed to support this acidic mantle, using ingredients like alpha-hydroxy acids (AHAs).
Dietary approaches are another area where pH therapy is often discussed, particularly concerning gut health. The use of probiotics can be incorporated into pH-responsive hydrogels to protect them from the acidic stomach environment and ensure their delivery to the gastrointestinal tract. This helps maintain a balanced microbial environment in the intestines, which can impact overall digestive health.
In alternative health circles, there is discussion about systemic pH balance, often promoting “alkaline diets.” These diets suggest that consuming fruits, vegetables, nuts, and legumes can make the body more alkaline, while foods like meat, dairy, and grains are considered acid-forming. While these diets often promote healthy food choices, the scientific basis for their ability to significantly alter systemic pH is limited.
Scientific Perspective and Misconceptions
Despite the popularity of certain pH therapy claims, scientific evidence supporting the ability to significantly alter systemic pH through diet or supplements is lacking. The human body possesses buffering systems, including respiratory control by the lungs and renal control by the kidneys, that maintain blood pH within a narrow range of 7.35 to 7.45. These mechanisms are efficient at neutralizing excess acids or bases, ensuring stability regardless of typical dietary intake.
A common misconception is that an “alkaline diet” can alter blood pH enough to prevent or cure diseases like cancer. Laboratory studies may show cancer cells thriving in acidic environments, but these in vitro conditions do not accurately reflect the complex regulatory systems of the human body. The acidity observed around tumors is typically a result of the cancer cells’ metabolic processes, not a cause that can be influenced by diet.
Leading oncology organizations, such as the American Institute for Cancer Research and Memorial Sloan Kettering Cancer Center, do not endorse the alkaline diet for cancer treatment or prevention due to a lack of direct clinical evidence. While a diet rich in fruits and vegetables, often recommended in “alkaline diets,” is beneficial for overall health due to its nutrient density and anti-inflammatory properties, this benefit stems from the nutritional content of the foods, not their ability to change blood pH. It is important to consult healthcare professionals for health concerns, as significant deviations in blood pH indicate serious underlying medical conditions that require professional diagnosis and treatment.