For those with an anaphylactic milk allergy, no amount of cheese is a good idea. There’s a bit more flexibility when it comes to an intolerance, though.
There are two types of sensitivities at play with dairy intolerance: one to lactose, the sugar in milk; the other to casein, or milk protein. The type of trigger affects what cheeses you can safely eat.
Lactose intolerance is more common, especially for particular ethnicities. It also frequently accompanies gut disorders like celiac disease, irritable bowel syndrome, Crohn’s disease, and SIBO (small intestinal bacterial overgrowth).
Yet, even if a lactose-intolerant person can’t sip some milk without bloating and pain, she can probably eat a variety of cheeses — so long as they’ve been aged at least six months. This rules out younger cheeses (think commercial Monterey jack and Colby, which are usually aged less than three months), but leaves a host of others.
As cheese ages, the fermenting bacteria that break down the milk’s protein convert lactose into lactic acid. In cheeses aged for longer time periods, like nine months to a year or more (think sharp cheddar, Gruyère, Manchego, Parmesan, and others) little, if any, lactose remains.
“If you’re eating an aged cheese and have a digestive issue, it’s likely not the lactose that’s the problem — it’s probably something else you’re sensitive to,” says Liz Thorpe, author of The Book of Cheese.
That brings us to casein, a milk protein that, for some, also causes digestive distress signals, as well as brain fog and fatigue. This sensitivity tends to pose a bigger problem than lactose intolerance for those who struggle with dairy, according to functional and integrative coach Cindi Lockhart, RDN, LD, IFNCP.
Most cow’s milk in the United States features A1 beta-casein, and our gastrointestinal system may not be able to properly break it down, she explains. These incompletely digested proteins can make their way into the bloodstream and eventually the brain, where they can lead to fogginess, fatigue, and cravings for more dairy.
If you notice these symptoms and they disappear when you avoid dairy, you may have a casein sensitivity.
But you still might be able to enjoy some goat and sheep cheese. (For more on dairy proteins, see Is A2 Milk Better for You?)