Nitric oxide (NO) is essential to the human body. It is produced by cells in the blood vessels and helps keep them open, prevent clots, and stop plaque from blocking blood flow. Blood pressure is also regulated by NO, as well as some immune and endocrine functions and communication between cells. Various factors can affect nitric oxide production in the body, such as exercise, diet, cholesterol, and disease. Alcohol, tobacco, and obesity often cause nitric oxide levels to decrease.
Cells in the inner layer of the blood vessels, called the epithelium, are generally responsible for nitric oxide production in the body. The chemical compound travels to the lining of vessels and can allow them to dilate, which usually lowers blood pressure. It can also stop blood cells from coagulating against artery walls. Production of NO in the human body can be stimulated by an amino acid called L-Arganine. Dietary sources of this substance are typically fish and meat, as well as grain, but supplements are often available commercially.
Vitamin E and vitamin C also stimulate nitric oxide production, either in food or in supplement form. Saturated fat can inhibit NO from being released, but omega 3 fatty acids can be beneficial because they can reduce levels of bad cholesterol that block nitric oxide. Fiber is often helpful as well in terms of cholesterol regulation. "Junk" food and foods that are fried, however, have a negative affect on NO production and often compound the problem by adding harmful fats to the blood stream.
Cells that line the walls of blood vessels, called endothelial cells, can also be stimulated to produce nitric oxide through exercise. Moderate workouts three days a week can be enough; this triggers the production of nitric oxide synthase which allows the body to make NO. Consumption of large quantities of alcohol, in contrast, can inhibit nitric oxide production, and so can smoking tobacco. There are also some prescription drugs that can inhibit it as well.
In addition to dietary and behavioral factors that affect nitric oxide production, some health conditions do as well. Heart disease and diabetes, as well as high blood pressure can be contributors decreased nitric oxide levels. Conditions such as neurological diseases, arthritis, and obesity can also contribute, and age can be a factor too. Supplements are often viable alternatives for increasing nitric oxide production, and there are also prescription medications that can do so as well.