Hidden lactose: where is it found and how can you identify it?

You cut out milk months ago. Yet after a sausage roll or a ready-made soup, your stomach still bloats. Sound familiar? You’re probably dealing with hidden lactose: milk sugar in products where you don’t expect it. Food manufacturers use lactose as a filler, flavour carrier and binder, so it turns up in bread, biscuits, breakfast cereal, instant soup, dressings, gravy, sausage and margarine. The good news: on pre-packed products it has to be listed, because milk is a legally mandatory allergen. You just need to know where to look.

In short

• Hidden lactose is milk sugar in products that don’t feel like dairy, such as bread, sausage, biscuits, dressings and instant soup.
• On pre-packed foods, milk and milk components must appear in the ingredient list and stand out visually, for example in bold.
• Ingredients such as milk powder, whey powder, whey protein concentrate, buttermilk powder and lactose point to lactose; lactic acid, lactate and cocoa butter do not.
• Medicines often contain lactose as an excipient too; the package leaflet states this and advises checking with your doctor if you have a sugar intolerance.
• EFSA concluded in 2010 that no general threshold exists: most people tolerate up to 12 grams of lactose in one go, but the limit varies a lot from person to person.

What exactly is hidden lactose?

Hidden lactose is milk sugar in a product that doesn’t look or feel like dairy. For manufacturers, lactose is a convenient ingredient: cheap, moisture-binding and a good carrier of flavour. A review in the Journal of Translational Medicine lists lactose in bread and baked goods, breakfast cereal, instant soup, sweets, biscuits, salad dressing, sausage, gravy, drink mixes and margarine.

Hidden lactose isn’t a different type of sugar, just the same lactose in small amounts in unexpected places. That’s exactly what makes it tricky: one such product rarely causes symptoms, but three or four in one day add up. If you’ve cut out dairy and think you’re in the clear, this is usually where it goes wrong.

Which products contain hidden lactose?

Hidden lactose mainly turns up in processed foods: bread, biscuits and cake, breakfast cereal and muesli bars, ready-made soups and sauces, dressings, gravy and stock cubes, cold cuts and sausage, flavoured crisps, chocolate, drink or instant mash powders, margarine and some sweeteners.

A few spots get overlooked again and again:

• Cold cuts and sausage. Milk powder is used to bind moisture and improve texture.
• Bread from the bakery counter. Loose bread has no ingredient list; allergen information should still be available, but you usually have to ask for it.
• Flavour powders. Crisps, seasoning mixes and powdered sauces use lactose as a carrier for flavourings.
• Sweeteners and tabletop sugar substitutes. Lactose appears here as a filler in tablet form.

For an overview by product group, see our article on where lactose is found; for a practical shopping list, read what you can eat with lactose intolerance.

How do you spot hidden lactose on the label?

Look in the ingredient list for milk and anything derived from it. In the European Union, “milk and products thereof (including lactose)” is one of the fourteen allergens that must appear in the ingredient list of pre-packed foods and stand out visually there, usually in bold or capitals. Note: it’s the name of the ingredient itself that’s emphasised, so you’ll see “whey powder” or “lactose” just as often as “milk powder”.

These ingredients point to lactose:

• Lactose, milk sugar
• Milk powder, skimmed milk powder, whole milk powder
• Whey powder, whey, whey protein concentrate, whey derivative
• Buttermilk powder, yoghurt powder, cream powder
• Cheese powder, milk solids, milk components

Some ingredients sound like milk but don’t contain milk sugar. Lactic acid (E270) and the lactates E325 to E327, the salts of lactic acid, have nothing to do with lactose despite the name. Cocoa butter is a plant fat from the cacao bean. And “milk protein” and caseinate are proteins; they may contain traces of lactose, but they aren’t the same thing.

With unpacked products, such as at a bakery, butcher or restaurant, there’s no label. Allergen information should still be available, but often only if you ask, so ask.

What does “lactose-free” mean on a package?

Less than you’d hope. There’s no harmonised EU threshold for “lactose-free” in ordinary foods. The review cited above notes that a fixed cut-off is missing and that manufacturers use different limits: below 0.01%, below 0.1% or below 0.5%. Only infant formula has a strict standard.

In practice, that means two things. “Lactose-free” almost always still contains a trace of lactose, usually too little to cause symptoms. And “low-lactose” says even less, since the limit used differs per brand.

A product can also naturally contain almost no lactose. In hard cheese, lactose is nearly fully converted within the first few days of production: in Parmigiano Reggiano, around 0.004 grams of lactose per 100 grams is measurable 48 hours after production. Fresh and soft cheeses contain more, because more whey, and so more lactose, remains in them.

Is there lactose in medicines?

Yes, often. Lactose is one of the most commonly used excipients in tablets and capsules, both prescription and over-the-counter. The amounts are small. Under EU guidance on excipients, lactose carries a “zero” threshold, and any lactose-containing medicine includes the standard wording: “Contains lactose. If you have been told by your doctor that you have an intolerance to some sugars, contact your doctor before taking this medicinal product.” A 2018 draft revision proposed a safe limit of 400 milligrams of lactose per dose for adults; that proposal has not been adopted.

The catch is in the total: taking several lactose-containing medicines a day adds up. If your symptoms coincide with a new medicine, discuss it with your pharmacist, who can check whether it contains lactose and whether an alternative exists. Never stop a prescribed medicine on your own.

How much hidden lactose can you tolerate?

That varies a lot from person to person, and that’s not an evasive answer but the current scientific position. EFSA concluded in 2010 that no general threshold can be set, precisely because of this individual variation. Still, the large majority of people who digest lactose poorly tolerate up to 12 grams in one go with no or mild symptoms, roughly a glass of milk. At the same time, EFSA describes that some people already report symptoms at 3 to 5 grams.

Two things help. Spread lactose across the day: higher amounts are better tolerated when spread out. And eat lactose with a meal rather than on an empty stomach. If you want to know where your own limit lies, keep a food and symptom diary for a few weeks; a dietitian can help you with that.

What can you do if you can’t avoid hidden lactose?

First, the simple answer: you don’t have to avoid everything. Going fully lactose-free is unnecessary for most people and makes your diet needlessly restrictive. Tackle the biggest sources and accept the small remainder.

For the moment you have no control over, a dinner out, a lunch meeting, a holiday, a lactase enzyme can help. Lactase splits lactose in the small intestine into glucose and galactose. In lactose intolerance, your body produces too little of it; a lactase supplement temporarily makes up the difference.

Which lactase products does Intoleran offer?

Lactase 20.000 is our strongest variant, with 20,000 FCC of lactase per scored tablet. Helps with the digestion of lactose*. You take half a tablet to two tablets right before or during a meal, up to 10 tablets a day; the enzyme stays active for 30 to 45 minutes. Suitable from age 2, vegan, gluten-free and soy-free, and low FODMAP Certified by Monash University. The scored tablet makes it easy to dose to the amount of lactose in your meal.

Lactase 2500 contains 2,500 FCC of lactase per tablet and is meant for fine dosing; the advice is 2 to 4 tablets per meal, up to 20 a day. Helps with the digestion of lactose*.

Lactase drops are stirred into milk or other non-acidic dairy; after 24 hours in the fridge at least 80% of the lactose is broken down. They aren’t suitable for acidic products such as yoghurt, quark and buttermilk. Helps with the digestion of lactose*.

Not sure which strength suits you? Try the product guide or put your question to our dietitian team.

* For individuals who have difficulty digesting lactose.

Practical tips for the supermarket

• Scan the ingredient list of pre-packed products for the bold words milk, lactose and whey; the standalone word “milk” isn’t always there.
• Learn to recognise five words: lactose, milk powder, whey powder, buttermilk powder, cheese powder. That covers most of it.
• Ask at the bakery, butcher and in restaurants for allergen information. It should be available.
• Spread lactose across the day and eat it with a meal rather than on an empty stomach.
• Keep a food and symptom diary for two weeks if you don’t know where your limit lies.

Do your symptoms persist, or do you notice weight loss, blood in your stool or ongoing stomach pain? See your GP. Not every stomach complaint comes down to lactose.

Not sure about your own situation? Our dietitians are happy to think it through with you, with no obligation to order anything.

Sources

• EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on lactose thresholds in lactose intolerance and galactosaemia. EFSA Journal, 2010.
• Facioni MS, Raspini B, Pivari F, Dogliotti E, Cena H. Nutritional management of lactose intolerance: the importance of diet and food labelling. Journal of Translational Medicine, 2020.
• European Medicines Agency. Annex to the European Commission guideline on excipients in the labelling and package leaflet of medicinal products for human use, rev. 1, 2019.
• European Medicines Agency. Draft: information for the package leaflet regarding lactose used as an excipient, EMA/CHMP/186428/2016, 2018 (draft, not adopted).
• Regulation (EU) No 1169/2011.

Written by Wieske Nieland, dietitian at Intoleran