ALLERGY HOTLINE COLUMNS
I’m writing this just before Christmas, when the world is preoccupied with lists of naughty and nice. Casein is definitely on my naughty list, so let’s take a closer look at it.
Casein is one of the two major protein groups in milk, whey being the other. Cow’s milk is about 80% casein. There are actually five different casein proteins in cow’s milk, but we can lump them all together for our purposes.
Manufacturing casein from milk is easy. In the old days, adding rennet caused the casein to form lumps that could be skimmed off as part of cheesemaking. Today a simple "iso-electric precipitation" will do it. The casein curd is washed to remove any lingering whey and lactose, and then dried and powdered.
Casein being an excellent bioavailable protein, food chemists
love to add it to just about every food in the supermarket. Its
only fault is that pure casein does not dissolve very well and
imparts a "gluey" taste. So the casein is chemically converted to
caseinate, which dissolves very well. Sodium caseinate is the most
common, although you can also find calcium caseinate and
potassium caseinate. In addition, there is the mysterious ammonium
caseinate, which you’ve probably never seen because
A Consumer's Dictionary of Food Additives, Updated Fourth
Edition, by Ruth Winters, says that it is "used in standard
foods, particularly bakery products. Therefore, it does not have
to be listed on the label."
One other variation exists, hydrolyzed casein, defined as "Casein that has been broken down partially or completely to its constituent amino acids."
Each manufacturing process takes the casein farther and farther away from its original milk source. Even so, those with cow’s milk protein allergies normally stay far away from casein in any form and in any guise. Fortunately, today’s labeling laws require processors to put "milk-derived" or a similar term when casein is included on an ingredients list. That’s good, but it doesn’t help when the casein is hidden inside a "standard product" or is lumped in with other "natural flavors" as part of a proprietary recipe.
If the food is certified kosher, by the way, the presence of any casein whatsoever will will require it to be marked as dairy, usually with a "D" next to the kosher symbol. Pareve products cannot contain casein. If you have doubts about a product, always contact its manufacturer.
What about those with lactose intolerance? The big question is, how perfect a job of removing the lactose do manufacturers do? Various older studies have found 0.4-1.2% lactose remaining in with the caseinate. On today’s products, however, you’ll often see "not a source of lactose" in bold letters after caseinate on an ingredients list, so techniques seem to have improved. (Or complaints started to pile up. Whatever works, I say.)
In any case, even 1.2% of a tiny amount is a tiny amount. I doubt if the amount of lactose in a product whose only milk-derived ingredient is caseinate is enough to trigger effects on even the most sensitive. You can always take a lactase pill with the food if you want to be doubly sure, of course. Or you can investigate the possibility that you have a milk protein hypersensitivity that is giving you LI-like symptoms. Or it could be something else. With food, you never know.