The truth about whey protein: Can I consume it if I’m lactose intolerant?

The short answer: Yes, but with caution. 

Although whey protein offers significant benefits, even for those with lactose intolerance, there are a number of considerations that need to be taken into account. Before trying any whey shake, make sure you do your research and get approval from your doctor. It’s important that you choose a protein powder that best suits your needs and health concerns.

The first thing to consider when it comes to whey protein powders is that they can offer significant health benefits when taken properly. Whey protein is a high-quality source of nutrition that provides easily-absorbable essential amino acids in adequate amounts. Other benefits of whey protein consumption include rapid muscle recovery, increased muscle synthesis, improved metabolism of body fat, and a better immune system response.

However, for many people who are lactose intolerant, the amount of lactose present in some protein shakes may contribute to uncomfortable symptoms (bloating, diarrhea, flatulence and abdominal cramps). Not all whey protein powders are created equal, and people with lactose intolerance should be aware of the differences.

What is lactose intolerance?

Lactose sensitive or intolerant individuals cannot fully digest lactose (a sugar found in milk and its derivatives), because their bodies do not produce enough lactase (the enzyme responsible for digestion of lactose).

Lactose intolerance is very common and can limit the foods you consume. About 65% of the world’s population have difficulty digesting lactose after childhood, according to data from the National Institute of Diabetes and Digestive and Renal Diseases of the United States (NIH). 

Lactose-containing foods that may need to be avoided, depending on the degree of your sensitivity, include milk products like ice cream, cheese, milk chocolates or yogurt; milk solids or milk powders; creams, buttermilk and curds.

If you know or suspect you have lactose intolerance, it is important to be mindful of what foods in your diet could be triggering an upset stomach—including protein shakes. Some people with lactose sensitivity or intolerance may choose to take lactase supplements when consuming foods they know or suspect to contain lactose. 

Does whey protein always have lactose?

Not all whey powders have significant amounts of lactose in them. Some are actually processed in such a way that makes them virtually free of lactose. Let’s look at how this is accomplished.

Whey protein powder is made from whey, the watery portion of milk. Straight from the cow, whey is 75% lactose, but when it’s used in foods and supplements, whey must be filtered. That filtration process reduces the lactose content considerably. Whey isolate protein powder is the most stringently filtered, resulting in whey protein with very low levels of sugar and fat. According to the Whey Protein Institute, whey isolate powders are about 90% protein, and—as a result of efficient processing—can be considered lactose free protein powder. 

However, it’s still important to check product labels if you are unsure. There may still be a chance of cross-contamination or trace amounts, but most lactose intolerant people will not notice this.

Which whey protein should you choose?

If you are lactose-intolerant and do choose to drink whey protein shakes, it is recommended that you only use whey isolate powder and avoid whey concentrates or powders that are a mix of isolate and concentrate. By having significantly lower levels of lactose, whey isolate can be a lactose-friendly option and allow for consumption of whey protein without those symptoms of indigestion typically linked with lactose.

Likewise using whey protein isolate not only limits the likelihood of discomfort, but is extremely pure protein, and there is little to no lactose in the final product. However, the best practice is to read supplement ingredient labels completely and contact the manufacturer if there is any doubt about how much lactose it may contain.

Lactose-Free Alternatives

Lactose sensitivity doesn’t have to derail your fitness goals. Whey protein is far from the only shake option on the market. There are also many widely accessible plant-based, dairy-free powders which include soy, brown rice, cranberries, collagen, pea, and hemp, while hydrolyzed beef, collagen, and egg powders exist as animal-based options.

As more and more people become aware of their own lactose sensitivity or intolerance, companies that produce protein powders and other nutritional products have responded by reducing the presence of lactose in their products and offering lactose free versions—including many lactose-free whey protein powders.