When I researched my book, Milk Is Not for Every Body, in the 1990s, I went to the whey manufacturers for guidance. I learned that whey protein concentrate was normally a high-lactose product, with as much as a 55% lactose content. Whey protein isolate, though, was a very low lactose product, with no more than 0.5% lactose. See my Lactose Percentages page for these and many other numbers.
Sometime in the 2000s, this began to change. I started seeing products containing whey protein concentrate labeling themselves as lactose free. This disturbed me because I didn't see how it was possible.
The FAQ page on the website of the Whey Protein Institute would seem to confirm this:
Q: If I'm lactose intolerant should I avoid whey protein?
A: Individuals with lactose intolerance should select a pure whey protein isolate, which has less than 0.1 gram of lactose per tablespoon (20 grams). This is less lactose than the amount found in a cup of yogurt and research has shown that most people with lactose intolerance have no trouble taking this very small amount of lactose. Individuals with lactose intolerance should avoid whey protein concentrates as they usually contain lactose and the amount can vary greatly from product to product.
Yet, entering lactose-free whey protein concentrate into Google yields numerous hits. And federal regulations require that any product that labels itself as lactose free must be completely lactose free.
So how is this possible? A new manufacturing process. Take a look at this Product Bulletin pdf from
Hilmar Ingredients. The site is protected so I can't copy directly, but here's a captured image of the relevant section if you don't want to click over:
The cross-flow microfiltration process is mentioned in various websites. I doubt if Hilmar is the only company to use it but the other hits I've seen have been to end users rather than manufacturers.
Anyone who is allergic to dairy proteins should of course stay away from these products despite their being lactose-free. They do give another option to those of us who are only lactose intolerant.