Cheese, Mutant Cows, Opioids, Constipation



If you love dairy, but have a temperamental stomach, you’ll want to read this one. If you have an iron gut… well… actually… with a title like “Cheese, Mutant Cows, Opioids, Constipation,” I bet you’ll probably find this interesting as well.



You may or may not know that much of the protein in cheese is a protein called casein. Now, while most mammals make a particular type of casein called A2 casein, many domesticated cattle also evolved a genetic mutation that allows them to make a second type of casein called A1 casein (sorry for the confusing nomenclature; the mutant second casein is A1). The difference between A2 and A1 caseins is that A1 casein protein differs in one single building block. (For those of you with some biochemistry background, A1 casein includes a Pro67His point mutation. For others, ignore this parenthetical.) The consequence of this change in structure is that A1 casein, but not A2 casein, is broken down in our guts to make a chemical called β casomorphin 7, which, as its name suggests is a morphine-like opioid!



Now, as a scientist, I don’t feel qualified to comment further on the potential addictive properties of cheese opioids. But, as a recovering cheese addict, I can’t help but smile and sympathize with the hypothesis.



But even if β casomorphin 7 isn’t strongly physiologically addictive, it has been shown to bind to receptors in the gut and cause constipation and other unpleasant gut symptoms. So, if you’re like me and love cheese (and may even be addicted) but also have a temperamental stomach, what are you to do!? Well, remember I said that only cattle evolved the genetic mutation to make A1 casein, and that only A1 casein can be broken down into β casomorphin 7? This implies that if you consume dairy sourced from other animals, your stomach won’t make β casomorphin 7 and you may experience less tummy trouble. There is even research to support this hypothesis (see links below). So, next time cheese upsets your stomach, don’t despair, just try to eat goat, sheep, or buffalo milk cheese instead!

Nicholas Norwitz

*The views and opinions expressed herein are those of the author and do not necessarily reflect the views of, its affiliates, or its employees.