In 30 seconds
- Lactose intolerance is a digestive problem; milk allergy is an immune system reaction. They are not managed in the same way.
- According to EFSA, most people with lactose intolerance tolerate up to 12 g of lactose in one go, roughly what a cup of milk contains.
- Whey isolate has far less lactose than concentrate: in typical industry values, 0.9% compared with 3.5-46.5%.
- If you are intolerant, check the label of each product and ask your doctor or dietitian.
It depends on two things: whether what you have is an intolerance or an allergy, and how much lactose your protein contains. With intolerance, many people tolerate small amounts of lactose, and whey isolate contains much less than concentrate. With a milk allergy, whey protein is not an option. Either way, check the label and ask your doctor or dietitian.
Not the same thing
Lactose intolerance versus milk allergy
Intolerance is not allergy
They are often confused, but they are different things 1:
- Lactose intolerance: this is a digestive problem. Your gut does not digest lactose, the natural sugar in milk, very well, and discomfort follows.
- Milk allergy: this is a disorder of the immune system. It has nothing to do with lactose, and it is managed differently.
If you have a milk allergy, whey protein is not for you, however little lactose it contains: it comes from milk.
What happens in your gut
To digest lactose, the small intestine makes an enzyme: lactase. When it produces too little, undigested lactose reaches the colon. There, bacteria ferment it and produce fluid and gas 2.
The result is the typical symptoms: bloating, wind, diarrhoea, nausea or abdominal pain. They usually appear within a few hours of having dairy, and they are more or less intense depending on the amount of lactose 2.
It is very common. It is estimated that around 68% of the world's population digests lactose poorly, although not everyone has symptoms: only those who do are considered intolerant 1. It is less common in northern Europe than in Africa or Asia 1.
According to EFSA
How much lactose most people tolerate in one serving
How much lactose you tolerate
This is the good news. Being intolerant does not usually mean zero tolerance.
EFSA reviewed the studies and reached a clear conclusion. Most people who digest lactose poorly tolerate up to 12 g in a single serving, with no symptoms or only mild discomfort 3. Spread over the day, larger amounts can be tolerated 3.
To give you an idea, 12 g of lactose is roughly what a cup of milk contains 4.
But everyone is different. EFSA itself points out that some people notice symptoms with less than 6 g, and that a single limit cannot be set for everyone 3.
Typical industry values
Lactose in each type of whey protein
Concentrate or isolate: the difference in lactose
Whey protein is obtained by filtering the whey left over from cheesemaking. The more it is filtered, the more protein remains and the less lactose and fat 5:
| Type | Protein | Lactose | Fat |
|---|---|---|---|
| 35% concentrate (WPC35) | 36.2% | 46.5% | 2.1% |
| 65% concentrate (WPC65) | 63.0% | 21.1% | 5.6% |
| 80% concentrate (WPC80) | 81.0% | 3.5% | 7.2% |
| 90% isolate (WPI90) | 90% | 0.9% | 0.8% |
Source: Tetra Pak, Dairy Processing Handbook. Typical dairy industry values; each product has its own composition.
The difference is huge. A low-purity concentrate can be almost half lactose by weight. A typical isolate, less than 1%. That is why, if you want to cut down on lactose, isolate is the type of whey protein that contains the least.
That said, “isolate” does not mean “lactose-free”. Always check the label and its warnings. And remember that if you make your shake with milk, the milk also adds its own lactose.
We go through the other differences in whey isolate or concentrate.
If you are intolerant: what the experts recommend
The NIDDK, one of the US National Institutes of Health, gives this advice 4:
- Talk to your doctor or dietitian before changing your diet, so that you do not miss out on any nutrients.
- Try yoghurt and hard cheeses, which contain less lactose than other dairy products.
- Use lactose-free or reduced-lactose milk and dairy products: they are just as nutritious.
- Lactase products can help you digest the lactose in dairy.
- Read labels: words such as milk, lactose, whey, curds or milk powder indicate that the product contains lactose.
- Do not cut out all dairy without professional advice: you could end up short of calcium and vitamin D.
For your shake, the simplest way to reduce lactose is to make it with water or lactose-free milk.
What about our protein?
Our Gourmet Isolate Protein is microfiltered whey protein isolate, the form of whey with the most protein: 42.8 g per 50 g serving, with 0.2 g of sugars.
It also contains DigeZyme®, a blend of five digestive enzymes: alpha-amylase, protease, lactase, lipase and cellulase. According to its manufacturer, each one deals with a type of nutrient; lactase, for example, is the enzyme that breaks down lactose 6.
It contains milk and soya, and its label states that it is not suitable for people who are allergic or intolerant to lactose or soya. If you have a diagnosed intolerance, ask your doctor or dietitian before taking any whey protein.
If you tolerate dairy well, it is a convenient way to add good-quality protein to your day. How much do you need? We explain it in how much protein you need a day.
Frequently asked questions
Does whey protein contain lactose?
Yes, because it comes from milk whey. The amount depends on the type: in typical values, a concentrate can contain between 3.5% and 46.5% lactose, and an isolate around 0.9%.
Can I take whey protein if I am lactose intolerant?
It depends on your tolerance and on the product. According to EFSA, most lactose intolerant people tolerate up to 12 g of lactose in one go, but some notice symptoms with less than 6 g. Check the label and ask your doctor or dietitian.
What is the difference between lactose intolerance and milk allergy?
Intolerance is a digestive problem: there is not enough lactase to digest the sugar in milk. Allergy is an immune system reaction. If you have a milk allergy, whey protein is not for you.
What is DigeZyme®?
It is a blend of five digestive enzymes: alpha-amylase, protease, lactase, lipase and cellulase. It is included in every serving of our Gourmet Isolate Protein.
Sources
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Definition & facts for lactose intolerance. View publication
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Symptoms & causes of lactose intolerance. View publication
- EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). Scientific opinion on lactose thresholds in lactose intolerance and galactosaemia. EFSA Journal. 2010;8(9):1777. View publication
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Eating, diet, & nutrition for lactose intolerance. View publication
- Tetra Pak. Dairy Processing Handbook, chapter “Whey processing”. View publication
- Sabinsa. DigeZyme®: multi-enzyme complex. Manufacturer's ingredient data sheet. View publication
Information based on published studies. It does not replace the advice of a doctor or registered dietitian. The results describe what was measured in each study, not the properties of any specific product. A varied and balanced diet and a healthy lifestyle are important.
