By Haley Davitz
Squalene is a compound found in both plants and animals used in the production of hormones and cholesterol. It has also been found to have immune functions, anticancer properties, and moisturizing abilities. Deep sea sharks have an abundance of squalene oil in their livers, where it makes up 40-60% of the liver mass to help these sharks maintain buoyancy.
Squalane is a derivative of squalene, produced by eliminating the double bonds in the squalene compound. Both forms are used in cosmetics such as moisturizing creams, lotions, lipsticks, hair conditioner, and other products. Because of the immune properties, squalene is also used in the medical field for cancer treatments and preventive care. Studies have confirmed that squalene improves the effectiveness of vaccines, and it is commonly used in vaccines for malaria, hepatitis B and C, herpes, and HIV. Squalene was used in multiple candidates for the COVID-19 vaccine as well.
That being said, it is no surprise that squalene is in high demand for its many uses, and that demand is only increasing.
How The Demand For Squalene Is Threatening Sharks
Unfortunately, the primary source of commercial squalene, as well as its derivative squalene, is shark liver. An estimated 3-6 million sharks are killed each year solely for the purpose of harvesting their liver—and that is in addition to the tens of millions that die from bycatch or shark finning. Sometimes, the liver is removed and the rest of the shark is thrown back into the ocean, a cruel practice to meet the demand for the squalene found in their livers.
The good news is, there are promising alternatives to shark liver for the precious squalene. Certain plants are also rich in squalene, specifically olive and amaranth oils.
Natural sources of squalene by quantity of squalene.
Image by Haley Davitz
In addition to plant sources, one highly sustainable option is the microbial production of squalene. Microorganisms such as bacteria and yeasts are known for their rapid growth abilities. A recent study showed that the metabolic systems of these microbes can be engineered to produce squalene at high rates, which could be used to meet the growing demand for cosmetic and medical squalene usage and spare millions of sharks.
Sources:
Lozano-Grande, M. A., Gorinstein, S., Espitia-Rangel, E., Davila-Ortiz, G., Martinez-Ayala, A.L. 2018. Plant Sources, Extraction Methods, and Uses of Squalene. Hindawi International Journal of Agronomy 2018:1-13.
Patel, A., Bettiga, M., Rova, U., Christakopoulos, P., Matsakas, L. 2022. Microbial genetic engineering approach to replace shark livering for squalene. Trends in Biotechnology 40(10):1261-1273.