Maybe She's Born with It, Maybe It's Squalene

In this day and age, we are becoming increasingly more aware of the impact that our modern society is having on the natural world. We try to rely less on our cars, we reduce, reuse and recycle, and we upcycle or thrift things rather than buy new things unnecessarily. If you and I have anything in common, maybe you give great consideration to how your food is sourced - maybe you only buy from local producers or choose sustainably fished seafood, maybe you are even vegetarian or vegan. These are all great efforts. But have you ever thought about how the cosmetics you buy might not be ethical or sustainable? Did you have any idea that many beauty products are contributing to shark overfishing!? You would not be alone if you ansewred 'no'. So why on Earth are sharks used in cosmetics? And, more importantly, can you avoid buying these products?

As well as for their fins and meat, sharks are also fished for their liver oils, such as squalene (Image Credit: Ethan / Unsplash)

Oil and Water

"Squalene" is a naturally occuring oily compound that can be found in many different plants, animals, fungi and other microorganisms. Shark's livers are very rich in squalene, where it aids in regulating their buoyancy. In human beings it is secreted by the skin, is present in our livers and intestines, and it is made during the process of steroid synthesis (Wang et al, 2022; Shalu et al, 2024).

Squalene is a naturally-occurring oil compound that can be found in many microorganisms, plants, animals and fungi (Image Credit: Ben Mills / WikimediaCommons)

With the ability to stimulate the immune system, squalene is a potent anti-inflammatory and anti-cancer agent. Therefore, it is used widely in pharmaceuticals, such as dietary supplements, medications and vaccinations. As it is so versatile and able to penetrate deeply into the skin, squalene is also an important ingredient in many cosmetics, especially skin care products, such as sunscreen and moisturisers (Cardeñosa, 2019; Wang et al, 2022; Hasan et al, 2023; Shalu et al, 2024; Suseno et al, 2024).

Sharks' livers contain a rich storage of oils such as squalene (Image property of Sophie Maycock)

Pouring Oil on Troubled Waters

Since it's discovery, the primary source of squalene has been shark liver oil, as this is the cheapest and easiest to harvest. Most commonly, this squalene is sourced from deep-sea species, like gulper sharks (Centrophorus granulosus) and spiny dogfish (Squalus acanthias). Studies of major brands have shown that many cosmetic products on the market today contain squalene sourced from sharks (Cardeñosa, 2019; Shalu et al, 2024).

Squalene is most commonly sourced from deep-sea sharks, like this spiny dogfish (Image Credit: NOAA National Marine Sanctuaries / WikimediaCommons)

"3000 sharks must be killed to produce one ton of squalene"

Shalu et al, 2024

Alarmingly, scientists have also discovered that there are many cosmetic products that contain squalene that has been sourced from species that are flagged as threatened by the IUCN Red List. For example, in a 2019 study scientists identified that the squalene in several major cosmetic brands' products was sourced from either Vulnerable blacktip sharks (Carcharhinus limbatus), Endangered smoothtooth blacktips (C. leiodon), Vulnerable graceful sharks (C. amblyrhynchoides) or Critically Endangered scalloped hammerheads (Sphyrna lewini) (Cardeñosa, 2019).

The Good Oil

The problem is that there it is almost impossible for consumers to make informed choices about squalene. It is very easy for manufacturers to hide shark-sourced squalene within products like cosmetics or pet foods because there is no legal standing requiring the sources to be displayed on their packaging. Ingredients lists will simply list 'squalene' without any further detail and unless a product is explicitly marketed as vegan, there can be no certainty about the source (Cardeñosa, 2019).

NGOs like the Shark Allies are campaigning for cosmetics companies to source their squalene from sustainable, shark-free sources (Image Credit: shark allies.org)

There have been several campaigns by NGOs to introduce labelling controls and logos that will allow consumers to identify products that do not contain shark squalene, but this is not a legal requirment yet in any country (Cardeñosa, 2019; Hasan et al, 2023).

Another issue is that there is no requirement to announce whether the squalene included in products has been sourced from threatened species. Even if companies were to get on board and agree to display the source of their squalene, the seafood supply chain is so fraught with fraud and mislabelling of products that it would be very challenging to ensure squalene had not been sourced from Endangered species of sharks (Cardeñosa, 2019; Hasan et al, 2023).

Despite being flagged as Endangered by the IUCN, gulper sharks are a very common source of commercial squalene (Image credit: D Ross Robertson / WikimediaCommons)

Burning the Midnight Oil

As sharks have been such a low-cost source for squalene, there was never a drive to investigate alternatives. However, as sharks (including deep-sea species) are now so severely in decline, it is vital that we discover a more sustainable way to produce squalene (Gohil et al, 2019; Shalu et al, 2024).

"There is increasing pressure on industries to switch from obtaining squalene from sharks to more environment friendly sources, such as plants and microorganisms"

Shalu et al, 2024

Scientists have started investigating using natural sources, such as plants or fungi, as an alternative. For instance, squalene can be sourced from olive and amaranth, wheat, rice bran, palm oil, Brazil nut, peanut, avocado, soybean, borage, peanut, macadamia, almond, pistachio and walnut plants, or from seeds such as ginseng, soybean, sunflower seed, flaxseed, pumpkin seed, apricot kernels, coriander seeds, sesame seeds, grape seeds, cottonseeds or Rosaceae. However, the methods to extract squalene from these sources cannot be scaled sufficiently to meet the market demand or the purification processes are too expensive to compete with shark sources. So researchers are now exploring more advanced biotechnological options (Wang et al, 2022; Finucci et al, 2024; Shalu et al, 2024).

Scientists are developing several different avenues for squalene production, in order to take some fishing pressure off of declining sharks (Gohil et al, 2019).

"Microbial fermentation" has become a promising alternative because it is very efficient and can produce a copious crop of squalene. This process involves altering the genes for biosynthetic pathways within microorganisms - such as bacterias, fungi or yeasts - so that they synthesise squalene. It might sound unbelievable, but these little cellular factories can be so incredibley efficient that they are able to produce squalene on an industral scale; making them a realistic alternative to animal-derived squalene (Wang et al, 2022; Shalu et al, 2024).

If companies could be urged to switch their methods and support sustainable sources of squalene, they could play a very important role in helping threatened species of sharks to bounce back from the brink of extinction. I for one would certainly be inclined to choose products that proudly displayed a logo announcing that their squalene is shark-free.

The demand for squalene is one of the drivers of severe overfishing that is driving sharks to the brink of extinction (Image Credit: Anastasios71 / Shutterstock)

If you want to ensure your cosmetics do not contain squalene sourced from sharks, you can check the company on SharkFree's list of shark-free certified brands. You can also support the Shark Angels and Shark Allies who are applying pressure to companies to introduce shark-free squalene sources into their supply chains.

References

Cardeñosa D (2019). Genetic identification of threatened shark species in pet food and beauty care products. Conservation Genetics, 20:6. Access online.

Finucci B, Pacoureau N, Rigby CL, Matsushiba JH, Faure-Beaulieu N, Sherman CS, Vanderwright WJ, Jabado RW, Charvet P, Mejia-Falla PA, Navia AF, Derrick DH, Kyne PM, Pollom RA, Wills RHL, Herman KB, Kinattamkara B, Cotton CF, Cievas J-M, Dakey RK, Ebert DA, Fernando D, Fernando SMC, Francis MP, Huveneers C, Ishihara H, Kulka DW, Leslie RW, Neat F, Orlov AM, Rincton G, Sant GJ,Volvenko IV, Simpfendorfer C & Dulvy NK (2024). Fishing for oil and meat drives irreversible defaunation of deepwater sharks and rays. Science, 383:6687. Access online.

Gohil N, Bhattacharjee G, Khambhati K, Braddick D & Singh V (2019). Engineering strategies in microorganisms for the enhanced production of squalene: advances, challenges and opportunities. Frontiers in bioengineering and biotechnology, 7:50. Access online.

Hasan MR, Chaplin JA, Spencer PB & Braccini M (2023). Consumption of shark products: The interface of sustainability, trade (mis) labelling, human health and human rights. Fish and Fisheries, 24:5. Access online.

Shalu S, Raveendranathan PK, Vaidyanathan VK, Blank LM, Germer A & Balakumaran PA (2024). Microbial squalene: A sustainable alternative for the cosmetics and pharmaceutical industry–A review. Engineering in Life Sciences, e202400003. Access online.

Suseno SH, Nugraha R, Nurjannah F, Ramadhan W, Arifah AU & Adha ASA (2024). Stability of shark (Centrophorus sp.) liver oil rich in squalene as an immunostimulant. In BIO Web of Conferences, EDP Sciences, 106. Access online.

Wang J, Hu H, Wang C, Jiang Y, Jiang W, Xin F, Zhang W & Jiang M (2022). Advanced strategies for the efficient production of squalene by microbial fermentation. Industrial & Engineering Chemistry Research, 62. Access online.

By Sophie A Maycock for SharkSpeak