Cod liver oil a versatile substance in previous generations

Submitted photoNot used anymore: Cod liver oil, a once all-in-one liquid, is seen in an old jar. The liquid is no longer used.

The pharmacy exhibit in the Vigo County Historical Museum always attracts a number of visitors. There is one bottle on the shelves that contains a liquid that was once familiar to all. That is cod liver oil, the oil that was used by industry, taken as a medicine, and despised by generations of children.

Cod fish are found in the cold waters of the Pacific and Atlantic Oceans. The origin of its medicinal uses dates back to the Vikings. Fish and fish liver oils were an important part of the Vikings diet. The oil was obtained by placing a cod liver on birch tree branches; the branches were laid over a large kettle of water. As the water in the kettle boiled, the liver would slowly cook, its oil dripping into the water. The oil would be skimmed off several times.

The oil from the cod livers soon proved to have industrial uses. From the beginning of the Industrial Revolution (mid 1700s) until the early 1900s, cod liver oil was used in leather tanning, lamp oil, woodworking, soap, paint, and other commercial applications. However, this oil was produced by simply packing the livers in wooden barrels, the lids securely fastened on, and letting them sit until they rotted. The oil that skimmed off from the rotten remains was usable, but was smelly, nasty, and full of pieces of dissolved liver. This oil was called brown oil.

It is this brown oil that was thought by many to cure diseases by applying the oil to the skin or taken by mouth. The change in processing the oil came in 1850 when Peter Moller developed a process by which the livers were ground into slurry, and then gently simmered until the oil rises to the top. The oil was skimmed off and purified. This method got rid of the smelly and nasty parts of cod liver oil, leaving it purer and lighter in color.

The final “transformation” of cod liver oil to a medicine came in the year of 1913, when two scientists, Elmer McCollum and Marguerite Davis of the University of Wisconsin discovered “fat-soluble A.” In 1922, McCollum found another vitamin in cod liver oil “fat-soluble D.” These two vitamins are essential nutrients: vitamin A for growth and healthy eyes and vitamin D for proper bone development. These two vitamins in cod liver oil became the basis for developing a dosage program for young children.

The reason for this became tragically clear in the crowded, unsanitary, and often smog-laden urban areas in the early 20th Century. The children would develop rickets, a bone disease that caused young bones to bend and become deformed. To prevent this, cod liver was given to children in a measured dose schedule.

Cod liver oil consumption reached its pinnacle between 1900 and 1950. But by the 1960s it was on the wane in the American household. Soon, the green bottle in the refrigerator with its odd-tasting, thick liquid (my own memory) disappeared forever.


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