Lactose intolerance: Foods to avoid and what to eat instead

Lactose intolerance is a disorder where people struggle to digest food that contains a sugar called lactose—commonly found in dairy products, like cow’s milk, cheese and cream. Around eight per cent of the population experience lactose intolerance in the UK.

Lactose intolerance happens when the small intestine does not produce enough lactase, the digestive enzyme that breaks down lactose so that your body can absorb it. 

Lactase deficiency is often genetic, and can be aggravated if you reduce dairy from your diet, as your body will become less reliant on and readily adapted to lactose. 

For some, lactose intolerance is one symptom of irritable bowel syndrome (IBS), where multiple foods, including dairy, spices, caffeine, alcohol and beans and pulses, irritate the stomach and intestines. 

One theory is that IBS is related to a sensitivity to FODMAPs, a group of short chain carbohydrates (sugars). Lactose is categorised under the D (disaccharides), meaning lactose is a high FODMAP food.

Lactose intolerance symptoms differ from person to person, and can vary from moderate to debilitating depending on the severity of your intolerance. 

Signs that you may be lactose intolerant include:

These symptoms will usually begin between 30 minutes and a few hours after consuming dairy. They will last as long as it takes for the lactose to leave your digestive system—usually up to 48 hours.

Other less common symptoms could be headaches, joint pain and eczema.

If you suspect that you have lactose intolerance, the obvious foods to avoid are anything that includes dairy.

That means cutting out:

Be mindful of foods that commonly include these ingredients, like chocolate, pasta sauces, curries, pizza and pastries. 

It is easy to be caught out by food products that include dairy as an additive. Some sliced breads use milk powder, as do some crisps. If you’re unsure, read the ingredients on the packet.

Ghee is an Indian butter that is often used in curry, but it may still be suitable for some lactose intolerant people because of its low lactose content. This will depend on how severe your intolerance is, and will take some trial and error to see if you can stomach it. 

Culturing, fermenting and ageing dairy to create end products like cheese and yoghurt naturally processes and depletes lactose, so some lactose intolerant people may find that they can still eat some dairy products. 

Hard cheeses like parmesan, for instance, contain only residual amounts of lactose. Blue cheese can have as little as 1.0g of lactose per serving. 

Some lactose intolerant people can still digest goats’ cheese and sheep's cheese (like feta and halloumi), and only need to avoid cheese made out of cows’ milk.

Goats’ cheese and sheep's cheese both contain lower amounts of lactose than cows’ cheese—though not by much. One study found that cows’ milk has a 4.93 per cent lactose content, where sheep's has 4.76 per cent and goats’ 4.33 per cent. 

Some researchers have suggested that lactose intolerant people can eat goats’ and sheep's milk because their fat globules are smaller, making them easier to digest and convert into energy. 

This is good news for people keeping an eye on their nutrition. Calcium deficiency can be a risk factor for lactose intolerant individuals who avoid dairy, which eating sheep's and goats’ cheese can prevent.

But, if you live in the UK, it is a good idea to be wary of halloumi, as commercial producers often bulk it out with cows’ milk. 

Some halloumi comprises as much as 95 per cent cows’ milk—Cypriots have taken to calling this industrial cheese “chewing gum cheese” to differentiate it from traditional halloumi.

Cutting out cows’ milk will help to reduce your symptoms, but it could also lead to deficiencies of vital vitamins and calcium.

The recommended daily intake of calcium for adults is around 700mg, which helps to improve bone health and stave off conditions like osteoporosis. 

Cows’ milk is a vital source of calcium for many, on top of vitamins A, B12 and D. In the absence of dairy, some may choose to take nutrient supplements instead. 

Eating other nutrient-rich food could be a more effective substitute though, as they have better bioavailability, meaning your body can absorb the nutrients more easily. 

Both goats’ cheese and sheep's cheese contain more calcium than cows’, and are also richer in vitamins A and B. 

If you are using alternative plant-based milks, like oat milk or almond milk, choose brands that fortify their drinks with calcium and vitamins. 

Other good sources of calcium include green leafy vegetables, like kale, or fish where you eat the bones, like sardines. 

Vitamin D, meanwhile, can be sourced from foods like oily fish (including salmon and mackerel), egg yolks and red meat.

Rather than cut out dairy altogether, some lactose intolerant people choose to take lactase supplements, which replace the lactase enzyme in your body.

Lactase supplements tend to come in pill form, and help to break down any lactose that you consume. It is generally recommended that you take one with the first bite of any meal that contains dairy.

While lactase can relieve your symptoms, it does not get rid of lactose intolerance completely. You may need to experiment with your dosage to work out how much you personally need to alleviate your reaction to dairy.

Lactose intolerance can be painful to experience, but it is not dangerous. It is important, however, to work out whether you are suffering from an intolerance or a milk allergy.

A milk allergy can trigger anaphylaxis, a severe reaction that is sometimes fatal if left untreated. It can also cause asthma-like respiratory symptoms, like:

You may also present with a rash or experience difficulty swallowing. This may accompany gastrointestinal problems similar to those suffered by lactose intolerant people, like stomach pain or diarrhoea. 

If you experience some of the symptoms above after eating dairy, you should seek medical attention immediately.