Naringin is the chemical compound in grapefruit that is responsible for its bitter taste. It is classified as a phytochemical, which is a naturally occurring plant compound with potential nutritional benefits. Specifically, naringin is a water soluble flavonoid. It has been studied for its potential antioxidant and anti-carcinogenic properties, as well as its effects on enzyme activity in the digestive tract. Supplements containing naringin are typically used to enhance the effects of other drugs.
The chemical formula of the compound is C27H32O14. It has a molecular weight of 580.53 and in its purest form, the compound appears as a yellow powder. Chemically, it is a conjugate of a sugar molecule and naringenin, which is another flavonoid present in grapefruit.
Generally, flavonoids protect cells from molecules that contain reactive oxygen atoms, commonly called free radicals. Usually, flavonoids reduce the damaging effects of free radicals by stimulating the production of glutathione, which is a strong anti-oxidant. Flavonoids can also increase the effectiveness of vitamin C as an anti-oxidant. In addition, flavonoids play a role in inflammation control by moderating certain cells of the immune system. They can also inhibit the activity of certain types of viruses, including the herpes simplex virus.
The main use of supplements containing this substance, in addition to preventing free radical damage, is to increase the bioavailability of nutrients. Basically, the amount of nutrients absorbed by the body is limited. A food may contain a certain amount of a vitamin, but a portion of it will not be absorbed by the body.
To increase the amount of nutrients absorbed by the body, the activity of several enzymes within the digestive tract is decreased by naringin. This prevents the breakdown of nutrients, allowing more to be absorbed into the blood stream. Usually, supplements are consumed while eating or along with other nutritional supplements to increase their absorption.
Generally, 25 mg of naringin is enough to increase the bioavailability of nutrients and drugs. The supplement is available in a pill, capsule or liquid form. Most of the benefits of the compound can be gained by drinking grapefruit juice.
Since the compound decreases enzyme activity in the digestive tract, the metabolism of drugs is also affected. The concentration of drugs in the blood generally increases when taken with naringin, which can lead to unexpected side effects. For example, a higher concentration of drugs designed to treat high blood pressure may lower the blood pressure to a point that causes fainting.