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Is it true that the foods and beverages you consume cause your blood to become more alkaline or acidic? Contrary to popular hype, the answer is: not to any significant degree. The pH of your blood is tightly regulated by a complex system of buffers that are continuously at work to maintain a range of 7.35 to 7.45, which is slightly more alkaline than pure water. If the pH of your blood falls below 7.35, the result is a condition called acidosis, a state that leads to central nervous system depression. Severe acidosis - where blood pH falls below 7.00 - can lead to a coma and even death. If the pH of your blood rises above 7.45, the result is alkalosis. Severe alkalosis can also lead to death, but through a different mechanism; alkalosis causes all of the nerves in your body to become hypersensitive and over-excitable, often resulting in muscle spasms, nervousness, and convulsions; it's usually the convulsions that cause death in severe cases. The bottom line is that if you're breathing and going about your daily activities, your body is doing an adequate job of keeping your blood pH somewhere between 7.35 to 7.45, and the foods that you are eating are not causing any wild deviations of your blood pH. So what's up with all the hype about the need to alkalize your body? And what's to be made of the claim that being too acidic can cause osteoporosis, kidney stones, and a number of other undesirable health challenges? As usual, the answers to such questions about human health can be found in understanding basic principles of human physiology. So let's take a look at the fundamentals of pH and how your body regulates the acid-alkaline balance of its fluids on a moment-to-moment basis. pH is a measure of how acidic or alkaline a liquid is. With respect to your health, the liquids involved are your body fluids, which can be categorized into two main groups: Intracellular fluid, which is the fluid found in all of your cells. Intracellular fluid is often called cytosol, and makes up about two-thirds of the total amount of fluid in your body. Extracellular fluid, which is the fluid found outside of your cells. Extracellular fluids are further classified as one of two types: Plasma, which is fluid that makes up your blood. Interstitial fluid, which occupies all of the spaces that surround your tissues. Interstitial fluid includes the fluids found in your eyes, lymphatic system, joints, nervous system, and between the protective membranes that surround your cardiovascular, respiratory, and abdominal cavities. Your blood (plasma) needs to maintain a pH of 7.35 to 7.45 for your cells to function properly. Why your cells require your blood to maintain a pH in this range to stay healthy is beyond the scope of this article, but the most important reason is that all of the proteins that work in your body have to maintain a specific geometric shape to function, and the three-dimensional shapes of the proteins in your body are affected by the tiniest changes in the pH of your body fluids. The pH scale ranges from 0 to 14. A liquid that has a pH of 7 is considered to be neutral (pure water is generally considered to have a neutral pH). Fluids that have a pH below 7 - like lemon juice and coffee - are considered to be acidic. And fluids that have a pH above 7 - like human blood and milk of magnesia - are considered to be alkaline. It's important to note that on the pH scale, each number represents a tenfold difference from adjacent numbers; in other words, a liquid that has a pH of 6 is ten times more acidic than a liquid that has a pH of 7, and a liquid with a pH of 5 is one hundred times more acidic than pure water. Most carbonated soft drinks (pop) have a pH of about 3, making them about ten thousand times more acidic than pure water. Please remember this the next time you think about drinking a can of pop. When you ingest foods and liquids, the end products of digestion and assimilation of nutrients often results in an acid or alkaline-forming effect - the end products are sometimes called acid ash or alkaline ash. Also, as your cells produce energy on a continual basis, a number of different acids are formed and released into your body fluids. These acids - generated by your everyday metabolic activities - are unavoidable; as long as your body has to generate energy to survive, it will produce a continuous supply of acids.