Ever since the earliest settlements along the coast, cod fishing and products have been crucial for livelihood, economy, and settlement, especially in Northern Norway, where cod fishing has been the very foundation of life.
Dating back to a time so distant that it is likely difficult to document, fat from the livers of cod and other fish species was used for illumination and heating. Both the Sámi people and the Inuit used fish and seal oil for light and warmth, and from the Middle Ages, the oil became commonly used as lamp oil by other Europeans as well. Various findings from the years 230-895 in Northern Norway suggest that fish, seal, and whale oil were not only produced for local use but also used as trade and barter commodities.
The uses of cod liver oil throughout the ages are very varied, and the oil was seen as a universal oil. The Norwegian Fisheries Museum has, through several sources, compiled a list of the various areas of use.
Uses of cod liver oil and other marine oils:
- Lamp oil (lysi) in cod liver oil lamps
- Ignition in ovens
- Dietary supplement for humans and livestock
- Medicinal use for humans and livestock
- Skin creams and ointments
- Lubricant for childbirth deliveries
- Impregnation of wood, leather, and hides
- Tanning of hides
- Paint production
- Dyeing processes in textile factories
- Soap production
- Wave suppression to prevent shipwrecks
- Lubrication of ship sides to prevent ice
- Hardening and turning of steel
- Explosive production in wartime industries
- Biofuel and lubricating oils for machinery
- Lubrication to loosen metal parts and screws
- Lubrication of ways for boat landings
- Alcohol dampening agent
- Offering to the gods
To survive in the dark and cold northern regions, a healthy diet rich in vitamins and omega-3 was essential. Even though these components in cod liver oil hadn't been discovered yet, cod liver oil was consumed because it was believed to be good for health. In the 1750s, Erik Pontoppidan, a professor and bishop, highlighted the health-promoting effects of cod liver oil for both external and internal use. Cod liver oil had long been a "folk remedy" for various ailments. It seems that in the past, people believed that cod liver oil helped with everything and was beneficial for overall health. Considering what we know today about fat-soluble vitamins and omega-3, this might not be far from the truth
The earliest documented use of cod liver oil for medicinal purposes dates back to 1789 when a doctor in Manchester used cod liver oil as a remedy for rheumatism. It was also suggested by doctors in 1824 as a treatment for rickets, a deficiency disease caused by a lack of vitamin D.
Sources: Schiøtz, O. (2010). Norsk olje gjennom 1000 år—Lofoten som global tranprodusent.