Squalene is a fatty compound that is found in a number of vegetables--including olive oil--but is usually extracted from shark's liver, where it is found in high concentration. Squalene is produced by the human body, where it is used to synthesize hormones, cholesterol and vitamin D. Recently, squalene oil has been marketed for cosmetic use and for its reported effects on cancer and as an antioxidant supplement.
Squalene's chemical similarity to human skin sebum has made it a popular component in natural cosmetic formulas designed to soften and protect the skin. The antioxidant properties of squalene have also been touted as being very beneficial for many skin conditions. In a study published in the International Journal of Cancer in July 2006, squalene was found to protect the skin of mice from developing tumors when exposed to carcinogenic substances.
Sharks are known for their apparent immunity to cancer, a property which may be due to the high amounts of sqaulene that they produce. A study published in the journal Cancer Epidemiology, Biomarkers, and Prevention in December 1997 found that squalene in olive oil may be responsible for disrupting the DNA synthesis sequence that causes cancer cells to grow. The authors speculate that the squalene in olive oil may be part of the low cancer incidence rate in the Mediterranean diet.
Extra virgin olive oils have significantly higher levels of squalene and are considered to have more of the antioxidant effects that are so beneficial to heart health. In a study published in the journal Pharmacological Research in September 2004, researchers found that adding squalene to the diet of rats had a protective effect on heart function when they were purposely given isoproterenol, a compound known to cause heart complications.
Squalene has also been recently used as adjunctive ingredient in vaccines, which has garnered much criticism and controversy. An article published on July 7, 2009 by Dr. Russell Blaylock on the website Newsmax claims that squalene was used in gulf war vaccines and may be responsible in part for gulf war syndrome. The article further claims that when squalene was injected into guinea pigs, they died.
Since squalene is a natural product that can be found in high amounts in quality olive oils and shark liver, it can be supplemented in the diet without resorting to an isolated squalene product. If isolated squalene does indeed have potentially toxic effects, it is possible that the other compounds in olive oil and shark liver oil mediate these effects and render them beneficial rather than harmful.