Whey protein and lactose intolerance: Can you drink it?

Lactose intolerance is a digestive disorder caused by the inability to digest the main carbohydrate in dairy products: lactose. 

If you have lactose intolerance, that means you don't make enough of the enzyme lactase. Lactase is needed to digest lactose. This lactase enzyme breaks lactose down into glucose and galactose so your body can use these simple sugars for energy. But without sufficient lactase, lactose moves through your gut undigested. When lactose isn’t digested, you may begin to experience symptoms like bloating, diarrhea and abdominal pain.

Lactose intolerance can limit the foods you consume. 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.

But what about the not-so-obvious offenders? Did you know foods like bread and baked goods, salad dressings, sauces, soups, breakfast cereals and cheese-flavored snacks can contain lactose in small quantities and could possibly upset your stomach?

If you know or suspect you have lactose intolerance, it is important to be mindful of what foods in your diet could be triggering to stomach upset— including your protein shakes.

Can protein shakes cause lactose intolerance?

The short answer: Protein shakes aren't going to cause lactose intolerance; they just may not be tolerated by someone who is intolerant to lactose.

Whether you can tolerate protein shakes depends on what type of protein you use to make your shakes. 

One of the most common types of protein used in protein shakes is whey protein. Whey is the by-product of cheese production. During cheesemaking, special enzymes are added to heated milk. These enzymes cause the casein in milk to change to a solid state and separate from a liquid substance. That liquid substance is the whey protein, which is washed and dried into a powdered form to become part of protein powder. 

Whey protein is especially popular among athletes or people who are looking to build muscle, as it is a complete protein source, containing all of the essential amino acids in adequate amounts, which serve as building blocks for muscles. Whey protein is also quickly absorbed, so the body is able to utilize the protein much faster (especially compared to other types of protein). A 2018 study looked into how much protein in a single meal can be used by the body for muscle-building and the implications for daily protein distribution. Researchers determined whey is a “fast-acting” protein: Whey’s absorption rate has been estimated at roughly 10 grams per hour. At this rate, it takes just 2 hours to fully absorb a 20 gram-dose of whey. To put that in perspective, a commonly recommended protein powder dosage is 1–2 scoops (around 25–50 grams) per day. If you consumed 20 grams of whey protein around the time of your workout, your body would be able to utilize that protein within two hours of exercising. This absorption rate allows whey protein to be particularly effective at increasing muscle growth when consumed within 2 hours either before, after or during a workout, as muscle protein synthesis is usually maximized in the time period after exercise. Whey protein also increases the release of anabolic hormones that can stimulate muscle growth and is high in the amino acid leucine, which is known to stimulate muscle protein synthesis.

It’s easy to see the appeal of whey protein for muscle building. But for many people who are lactose intolerant, the lactose in whey protein unfortunately renders it a non-option. So if you’re lactose intolerant and you’ve been using whey protein for protein shakes, then your protein shake may contribute to uncomfortable symptoms (bloating, diarrhea, flatulence and abdominal cramps).

What happens if you have whey protein powder when you’re lactose intolerant?

Although whey protein powder is made from the lactose-containing liquid part of milk, the actual amount of lactose in whey protein powder varies by product. Most dairy protein powders are processed enough that a lot of the lactose is actually removed.

There are three main types of whey protein powder: whey concentrate, whey isolate and whey hydrolysate. Whey isolate contains around 90 percent protein and less lactose than whey protein concentrate. Because whey isolate is more processed and contains less lactose, people who have lactose intolerance might not feel the effects of the lactose as much as they would if they were to consume whey concentrate, which contains around 80 percent protein along with more lactose. Whey hydrolysate contains a similar amount of lactose as whey concentrate.

That means lactose-sensitive individuals might be able to handle whey protein isolate, despite the fact that it contains lactose. 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.

What protein powder is best for dairy intolerance? Lactose-free, vegan options for weight loss and muscle building

While whey protein isolate can be a great option for those with lactose-intolerance, depending on the severity of lactose sensitivity, the small amount of lactose present in it can still be an issue for some people. Fortunately, whey protein isn’t the only quality protein powder type on the market. There are a number of completely lactose-free protein products out there, and, yes, you’ll still be able to achieve the same gains that you would by consuming whey protein powder or milk protein. Two of the most popular dairy-free protein powders are made from pea protein and brown rice protein.

Pea protein powder is a supplement made by extracting protein from yellow split peas. The protein is isolated from the ground yellow peas and formed into a powder. Not only is pea protein a high-quality protein and a great source of iron, it’s also naturally vegan, hypoallergenic and one of the more easily digested plant-based proteins. This makes it a great option for people who are lactose intolerant.

In addition to being free from cow’s milk or dairy, pea protein does not contain any of the top food allergens (which includes peanuts, tree nuts, eggs, fish, shellfish, wheat and soy). It does contain all nine essential amino acids and is a great source of branched-chain amino acids (BCAAs) — particularly arginine, which promotes healthy blood flow and heart health. And the best part for people with dairy intolerance: There’s no gas or bloating from pea protein like some may experience with whey protein, due to pea protein’s digestibility and lack of allergens.

Another option is brown rice protein, which is a protein supplement made from brown rice that’s converted into powder form. The brown rice is treated with select enzymes that cause the protein and carbohydrates that make up the rice to separate. The protein is isolated, resulting in a powder. Like pea protein, brown rice protein is hypoallergenic and able to be consumed by people with milk allergies. While brown rice protein does not provide all nine essential amino acids and is lower in lysine, blending it with another plant protein source, like pea protein, makes up for these limiting nutrients, creating a complete protein source.

Protein supplements like pea protein and brown rice protein can be beneficial to people looking to lose weight, as pea protein has a high fiber content that helps stabilize blood sugar levels and keep the body satisfied, and brown rice has a thermic effect. This means brown rice protein creates heat in the body through the process of digestion. Since proteins take a lot of energy to digest, you’ll burn calories even after you’ve completed your workout because you consumed a lean protein like brown rice that produces a thermic effect. 

Protein supplements like pea protein and brown rice protein can be beneficial to people looking to lose weight, as pea protein has a high fiber content that helps stabilize blood sugar levels and keep the body satisfied. (That said, be sure to read the labels of your protein powder. Although peas and brown rice have a high fiber content, the amount that ends up in the protein powder itself can often be quite low — around 1 gram per serving.) People are drawn to brown rice protein powder because brown rice has a thermic effect. This means brown rice protein creates heat in the body through the process of digestion. Since proteins take a lot of energy to digest, you’ll burn calories even after you’ve completed your workout because you consumed a lean protein like brown rice that produces a thermic effect. 

In addition to brown rice protein and pea protein, some other sources of plant-based protein include hemp protein, soy protein, almond protein, brazil nut protein, chia seed protein, cranberry protein, pumpkin seed protein and even sacha inchi protein. 

Helping lactose intolerant people find a protein powder

If you’re sensitive to lactose and want to find a protein powder that fits your needs but are unsure where to start, Gainful can help. Gainful offers personalized protein powders that are tailored specifically for you. You start by taking Gainful’s quiz, select your dietary restrictions, preferences and overall wellness goals and then Gainful takes care of the rest. If you’re uncertain about which lactose-free protein powder is right for you, Gainful will lead you in the right direction and help you create the customized protein powder you’re looking for. Each subscriber also has unlimited access to a personal Registered Dietitian, who can answer any questions you may have about your protein powder, lactose intolerance, side effects from eating dairy foods and more. 

There are tons of protein powder options out there for people who are sensitive to lactose, and Gainful can help you find the best one for you.