Why Cats Like Tuna Fish


        By Dr. Michael W. Fox

According to a scientific study of dried and processed Black Soldier fly larvae BSFL) by Scott J McGrane and associates, (Umami taste perception and preferences of the domestic cat (Felis catus), an obligate carnivore, Chemical Senses, Volume 48, 2023, bjad026, https://doi.org/10.1093/chemse/bjad026)

Cats have receptors in the taste buds on their tongues that detect umami, the savory flavor found in meat — and tuna in particular. In cats, as in humans, the umami receptors are triggered by a combination of amino acids and nucleotides. Cats’ taste buds seem to be particularly attuned to histidine and inosine monophosphate, compounds tuna contains in high amounts. In tests with 25 cats that were given flavored water, “it was one of the most preferred combinations”, says flavor researcher and co-author Scott McGrane. “It really seems to hit that umami sweet spot.” Why cats have evolved a taste for tuna remains a mystery.

I checked other research reports and solved this “mystery”. The domestic cat is a descendant of Felis lybica, the African wildcat. They hunt primarily mice, rats, birds, reptiles, and insects. It is likely that insectivorous reptiles and birds contain these same amino acids and nucleotides (from consuming insects) which cats like to eat, along with insects that are part of the wildcat’s diet.

According to a scientific study of dried and processed Black Soldier fly larvae (BSFL) by N.F.N.M Zulkifli and associates, (Nutritional value of black soldier fly (Hermetia illucens) larvae processed by different methods. PLoS One. 2022 Feb 25;17(2):e0263924. doi: 10.1371/journal.pone.0263924) “The tested BSFL meals were considered to have a good profile of essential amino acids (EAAs), with leucine, lysine, valine, and histidine being the dominant EAAs. Nucleotides such as inosine monophosphate and uridine monophosphate occurred in all the BSFL meals.”

This answers the question as to why domestic cats like tuna fish since there were no fish in the desert from where they originated but tuna fish contains similar nutrients that cats enjoy. Cat food manufacturers use tuna fish to make their products more appetizing.

Because of mercury and other contaminants, and the fact that many cats are allergic to fish, I do not advise feeding tuna to cats. We should also be helping the oceans restore natural biodiversity now under threats from climate change and over-harvesting of marine life for human consumption and livestock and farmed-salmon feed.

We may soon be seeing various high-nutrient ingredients derived from farmed insects in cat and dog foods.