 You may already know that salt is the common term for sodium chloride, which is an ionic compound consisting of sodium ions and chloride ions, arranged in a 3D lattice structure. You can learn more about the properties and the extraction of salt in other videos on this channel. In this particular lesson, we will concentrate on the importance of salt in our diets. Regular table salt is used worldwide as a flavor enhancer. In fact, salt and pepper are the two most common condiments anywhere in the world. Most salt for consumption is iodized. This means that iodide ions have been added. This iodized salt helps to prevent the enlargement of the thyroid glands, a medical condition known as a goiter. Besides making our food tastier, salt is also used as a preservative. It delays food from spoiling by killing bacteria and mold. To illustrate this process, let's use a piece of meat as an example. There are quite a lot of bacteria living on and inside the meat, but most are killed when it is cooked. If we didn't eat that piece of meat immediately, we could refrigerate it or we could preserve it. Refrigeration slows down the spoiling process by decreasing the optimal temperature for bacteria to survive and multiply. A common food preservation method is known as curing. Curing involves rubbing meat with a lot of salt. So if we rubbed that piece of meat with a lot of salt, a hypertonic environment is created. This means that there is a higher solute concentration outside of cells rather than inside. Osmotic pressure, therefore, is increased. This draws water out of cells, including water inside of bacteria living on and inside that piece of meat. These bacteria are killed and the meat is preserved. Most cured meats are also smoked to further dehydrate the meat and to add flavor. Food can also be preserved by pickling. Curing is done by creating a dry environment, whereas this pickling process is done in an aqueous environment. This is done by placing the food item in brine or salty water. The same idea occurs here. A hypertonic environment is created. Osmotic pressure is increased. This draws water out of bacteria cells, thereby killing them. These cured and pickled food items usually have a salty, savory taste to them. Usually, other preservative agents, such as nitrites, are added. But historically, salt is the most common preservative. Salt is also the most common food additive in processed foods. It can be found in rather high quantities in crisps, tinned food, and most fast foods. We actually need salt in our diets to maintain normal cell function, nerve cell conduction, and normal blood pressure. Too much salt in our diet, however, will lead to many health issues. It raises blood pressure, which can lead to many cardiovascular or heart diseases. The medical term for increased blood pressure is hypertension. When we consume salt, some of it is used for vital bodily processes, and the remaining is excreted through our urine. But when too much is consumed, our kidneys cannot work fast enough to remove this excess salt. This excess salt ends up in our bloodstream, causing water to be drawn out from our blood vessel cells through osmosis. What effect do you think this has on our total blood volume? Pause, think, and continue when ready. Blood volume increases, and this increases blood pressure because there simply isn't enough space for this extra volume. The blood vessel walls actually overcompensate by creating thicker and stronger cells to withstand this additional pressure. This further increases blood pressure. Untreated high blood pressure can lead to strokes, which can be caused by blood vessels in your brain bursting. Increased blood pressure also means that your heart as a muscle has to pump harder to get blood flowing through these smaller vessels. This causes the heart muscles to enlarge over time, and can lead to heart failure when the pumping mechanism doesn't work as well as it should. Decreasing overall salt consumption can prevent these health issues. On food packaging labels, salt is usually labeled as sodium. The recommended daily intake of salt is actually around 1500 megs per day for an adult, or less than a teaspoon full.