Lactose intolerance: foods to avoid, hidden lactose and what you can still enjoy

With lactose intolerance, the foods most likely to cause symptoms are the ones highest in lactose, the natural sugar in milk: milk, cream, ice cream, soft cheeses, custard, evaporated and sweetened condensed milk, and foods made with them. Lactose also turns up in less obvious places, such as baked goods, processed meats, soups, salad dressings and protein powders. The good news is that most people do not need to remove lactose completely. Many can enjoy hard cheeses, yogurt, lactose-free milk and small amounts of regular dairy with meals.

According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), research suggests many people with lactose intolerance can have about 12 grams of lactose, roughly the amount in 1 cup of milk, with no symptoms or only mild ones. Your own amount may be higher or lower, which is why it helps to learn your personal tolerance rather than follow a fixed list.

Lactose intolerance means having digestive symptoms, such as bloating, diarrhea and gas, after eating or drinking lactose. The underlying cause is lactose malabsorption: the small intestine makes too little lactase, the enzyme that breaks lactose down. Undigested lactose travels to the colon, where bacteria ferment it and produce fluid and gas, NIDDK explains.

Lactose malabsorption is very common. NIDDK estimates that about 68% of the world’s population has it, and about 36% of people in the United States. Not everyone with malabsorption has symptoms, and only people who have symptoms are considered lactose intolerant.

• Primary lactose malabsorption (lactase nonpersistence) is the most common type. Lactase production declines after infancy, and symptoms may first appear in later childhood, the teen years or early adulthood.
• Secondary lactose malabsorption follows injury to the small intestine, for example from celiac disease, Crohn’s disease, infections, some medicines, surgery or radiation. Tolerance may return once the underlying cause is treated.
• Congenital lactase deficiency is rare, and means little or no lactase is made from birth.

Lactose intolerance is not the same as a milk allergy. A milk allergy is an immune reaction to milk proteins and can be serious. If that applies to you, lactose-free products are not a safe swap. Our guide to lactose-free vs dairy-free walks through the difference.

Symptoms usually start within a few hours of eating lactose and can include bloating, diarrhea, gas, nausea, stomach pain and rumbling. The amount of lactose matters: more lactose generally means stronger symptoms. If symptoms are new, changing or severe, talk with your doctor. Testing, such as a hydrogen breath test, can be arranged by a clinician, and the NHS advises against cutting foods out without advice from a doctor or dietitian.

Lactose is not only in obvious dairy. It turns up in many packaged foods. NIDDK suggests checking ingredient lists for these words:

• Milk
• Lactose
• Whey
• Curds
• Milk by-products
• Dry milk solids
• Nonfat dry milk powder

Foods that often contain lactose include:

• Baked goods: bread, cakes, cookies, pastry and crackers
• Processed foods: breakfast cereals, instant potatoes, soups, margarine, salad dressings and flavored snacks
• Processed meats, such as some sausages and deli meats
• Meal replacements, smoothies, protein powders and bars
• Nondairy creamers and whipped toppings, which can still contain milk ingredients
• Sauces and milk chocolate, including creamy sauces

Some prescription and over-the-counter medicines also contain small amounts of lactose. If you are concerned, ask your pharmacist. Never stop or change a medicine on your own.

Dairy is not all the same. NIDDK notes that yogurt and hard cheeses, such as cheddar or Swiss, are lower in lactose than other milk products. Monash University, which researches FODMAPs, lists hard cheeses and butter among foods naturally low in lactose, while milk, soft cheeses, yogurt, custard and ice cream are listed as higher in lactose.

Yogurt sits in the middle. It still contains lactose, but many people find it easier than a glass of milk. Whether it works for you depends on the type, the amount and your own tolerance. A small serving with a meal is a gentler way to find out than a large bowl on its own.

A few habits can make dairy easier to tolerate, based on NIDDK guidance and Monash University’s advice on lactose:

• Have small amounts of milk at a time, with meals rather than on their own.
• Spread lactose-containing foods across the day instead of having them all at once.
• Add milk products back gradually and notice how you feel.
• Choose hard cheeses and yogurt when you want regular dairy.

Monash also notes that some research suggests gradually building up daily lactose intake may improve tolerance over time. This is worth discussing with a dietitian, especially if you have IBS or another digestive condition.

Lactose-free milk and dairy have the lactose broken down, so they are easier to digest while keeping nutrients such as calcium and protein. NIDDK says lactose-free and lactose-reduced products are widely available and are as nutritious as regular versions. They do tend to cost more, and Monash points out that they will not help build tolerance.

Lactase products are enzyme drops or tablets sold at pharmacies. Taken with lactose-containing food or drink, they help break lactose down. The NHS notes that a lactase supplement taken just before eating or drinking lactose may reduce or prevent symptoms for some people. Follow the product’s dosing instructions and check with your doctor or pharmacist if you take other medicines.

Plant-based drinks such as soy, oat or almond contain no lactose. They differ a lot in protein and calcium, and Monash notes that not all of them are low in other FODMAPs. If you use them in place of milk, check the label for added calcium.

Milk and milk products are the most common sources of calcium in many people’s eating, and NIDDK notes that lactose intolerance can lead to too little calcium and vitamin D, which may raise the risk of osteoporosis. Keeping dairy you tolerate, or choosing lactose-free versions, is one of the simplest ways to protect these nutrients.

Non-dairy sources of calcium listed by NIDDK include:

• Canned salmon or sardines with soft bones
• Broccoli and leafy greens
• Oranges
• Almonds and Brazil nuts
• Dried beans
• Tofu
• Foods and drinks with added calcium

Vitamin D helps your body absorb and use calcium. Sources include eggs, fish such as salmon, some cereals, orange juice and milk products with added vitamin D. Sunlight also helps your body make vitamin D.

Talk with your doctor or a registered dietitian before making big changes to how you eat, and before taking supplements. They can help you meet your needs in a way that suits your tastes, budget and any other conditions you manage.

Because tolerance varies so much, a personalized approach usually works better than avoiding all dairy. Here is a gentle way to work it out with your care team:

1. Talk with your doctor about your symptoms first, so other causes such as celiac disease or IBD can be considered. Lactose problems can sometimes be secondary to these.
2. Keep a simple food and symptom diary for a week or two, noting what you ate, how much, and how you felt.
3. With your doctor or dietitian, try reducing the highest-lactose foods for a short period and notice whether symptoms change.
4. Reintroduce dairy step by step, starting with hard cheese or a small amount of yogurt with a meal, then small amounts of milk.
5. Keep the foods that work for you, and use lactose-free products or lactase enzymes where they help.

If you have IBS, lactose is only one possible trigger. Garlic, onion and certain fruits can cause similar symptoms, so it helps to look at the bigger picture. See high-FODMAP foods and swaps and our guide to fructose malabsorption for related triggers.