We received a question from a reader named Linda about milk protein ingredients and lactose intolerance. “I am highly lactose intolerant as shown by the hydrogen breath test (one of the highest they’d ever tested), so I read a lot of labels. Can you tell me if there is lactose in whey, casein, caseinate or any variation of that?” That’s a good question, since the answer is a little more nuanced than you might think.
Are Casein and Whey Safe for Lactose Intolerance?
First, lets do a very quick and basic primer on the chemistry of lactose intolerance. Lactose is a disaccharide made up of two simple sugars: glucose and galactose. Basically, it’s milk sugar. When someone is lactose intolerant, they lack enough lactase enzyme in their digestive system to break down the lactose into simple sugars. The whole carbohydrate then passes through, and can cause digestive distress (aka lactose intolerance symptoms).
Casein and whey are two major types of proteins found in milk. They are protein molecules while lactose is a sugar molecule. In other words, they are separate components in milk that can be isolated from one another. So in theory, someone who is lactose intolerant (and not allergic to milk proteins) should have no issue with isolated casein or whey milk proteins. But there are some caveats to consider when reading food labels.
Casein and Lactose Intolerance
Casein is the most abundant type of protein in milk. Four types of casein make up about 80% of the proteins in cow’s milk. The majority of people with a milk allergy are allergic to casein specifically. Because of its properties, casein is often extracted from milk and used as a binding agent in various products, from food to paint. Caseinates are compounds made from casein that are water soluble, making them easier to use in many applications.
As noted above, casein itself does not contain lactose. It’s merely a protein molecule. But it needs to be completely isolated to be free of lactose. Casein protein powders, for example, might not be 100% isolated, and could contain lactose. And even with isolated casein and caseinates, there is always a risk that a small amount of lactose could remain. Low levels of lactose might not be an issue for most people who are lactose intolerant, but could be a problem for people who are highly lactose intolerant.
Whey and Lactose Intolerance
The other 20% of proteins in milk are collectively referred to as whey proteins. Like casein, people can be allergic to whey proteins. But isolated whey proteins on their own are protein molecules and do not contain lactose. However, whey is often a bit trickier in our food supply.
As an ingredient, it’s often simply listed as “whey.” If you just bought whey, there’s a good chance it wouldn’t be purified and would contain lactose. In some cases, whey powder can have a very high concentration of lactose. You might see whey listed as whey protein concentrate or whey protein isolate. This sounds like a safer bet, right? Unfortunately, these terms don’t equate to lactose free.
Whey protein concentrate is a protein concentrated form of milk powder. The concentration of whey protein in this ingredient typically ranges from 30% to 80%. The remaining 20% to 70% is primarily made up of lactose, other carbohydrates, and fat. Whey protein isolate is more concentrated, and will usually be at least 90% whey protein. But again, that leaves up to 10% of other milk components, including lactose.
There are highly isolated forms of whey that are processed to remove lactose, but you need to dig a bit to confirm the whey concentration. And of course, trace lactose could still remain. Also, use caution with 100% whey protein powder labels. Sometimes this means that all of the protein in the powder is whey protein, not that the protein used is a 100% pure isolate.
Lactose-Free Casein and Whey Proteins
Of course, you can look for a lactose-free label on the food you are considering. This can be a helpful starting point when considering foods containing casein, caseinates, or whey proteins. But make sure the company understands what lactose-free means and that they have verified their ingredients.
There is no FDA definition or regulation governing the term “lactose-free.” There is a truth in labelling law, but no specific guidance for using lactose-free on labels. Consequently, lactose-free products can still have a small amount of lactose remaining, and many do. This is rarely considered a problem for lactose intolerant consumers, but could be an issue for the highly intolerant.
More Related Topics on Lactose Intolerance
- Lactose Intolerance: A Normal Reason to be Dairy Free
- What is Lactase? Can it Help with Lactose Intolerance?
- Lactose and Medications
- Should Lactose Intolerant Children Consume Dairy? Understanding the Options
- Is Lactoferrin Dairy Free? Is it Safe for Lactose Intolerance?
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