Shark liver oil

Shark liver oil is obtained from sharks that are caught for food purposes and are living in cold, deep oceans. The liver oil from sharks has been used by fishermen for centuries as a folk remedy for general health. It is purportedly useful for healing wounds, sores, irritations of the respiratory tract and the alimentary canal and for lymph node swelling.^{[citation needed]}

Shark liver oil is rich in alkylglycerols, which are naturally found in mother's milk and in bone marrow.^{[citation needed]} It also contains pristane, squalene, vitamins A, D, omega-3 fatty acids, triglycerides, glycerol ethers, and fatty alcohols.^{[citation needed]}

None of these claims are medically validated, and shark liver oil (alone) is not a medication prescribed or utilized by American physicians. However, it is a component of some very popular hemorrhoid medications commercially available in the US where it reputedly has the capacity to shrink inflamed blood vessels. Recently the labeling of these medications has been altered to call shark liver oil an inactive ingredient, although it was previously cited as an active ingredient and still is in some generic preparations.

Shark oil barometers

Traditionally, Bermudians rely on unique shark-oil based "barometers" to predict storms and other severe weather. Small bottles of oil are hung outside.

Medicinal Use

Most shark liver oil supplements have not been tested to find out if they interact with medicines, foods, or other herbs and supplements. Even though some reports of interactions and harmful effects may be published, full studies of interactions and effects are not often available.

Although many people have taken shark liver oil, the issue of potential toxicity at the usual doses has not been well studied. Some mild digestive problems such as nausea, upset stomach, and diarrhea have been reported. Some animal studies have found that shark liver oil and its components may raise blood cholesterol levels. A Japanese study found some shark liver oil supplements to be contaminated with polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). PCBs can have harmful effects in humans, and may increase the risk of some types of cancer. People with seafood allergies may also react to shark liver oil.