Lactose Intolerance and Milk Allergies

As part of the NHS’ Food Allergy and Intolerance Awareness Week, today we’re looking at lactose intolerance and milk allergies. People often wrongly assume that these are one and the same, but in reality they are quite different.


First, let’s look at lactose intolerance:

During digestion, your body produces an enzyme called ‘lactase’, which breaks down lactose into two simpler sugars – glucose and galactose. These two sugars, unlike lactose, are easily absorbed into the bloodstream.


Some people do not produce enough, if any, of the lactase enzyme and so they are unable to break down lactose efficiently. It then stays in the digestive system and is fermented by bacteria, causing the symptoms associated with lactose intolerance, such as:

  • flatulence (gas)
  •  bloating
  • stomach pains/cramps
  • diarrhoea (3 or more times a day)
  • nausea

The severity of these symptoms and how quickly they strike largely depend on the amount of lactose consumed. The amount of lactose it takes to instigate a reaction varies from person to person; in severe cases, just a drop of milk in coffee can cause a reaction.

Who is affected?

Lactose intolerance is generally considered an adult-onset condition as most cases first develop in people aged between 20 and 40 years old. In rare cases, the condition can be present from birth. Lactose intolerance equally affects both men and women. Interestingly, it is more common among some ethnic groups than others. For example, almost all people of Chinese descent are lactose intolerant, whereas only 1 in 50 people born of Swedish descent have some degree of lactose intolerance. In the UK, lactose intolerance is more common in people of Asian and African-Caribbean descent.


The main treatment for lactose intolerance is to limit your intake of lactose. Depending on the severity of the intolerance, additional calcium and vitamin D supplements may also be required in order to maintain healthy bones. Lactase substitutes are also available, which you can take to improve your digestion of lactose.

If you suspect you might be lactose intolerant, you should always consult your doctor to obtain an official diagnosis before making any changes to your diet. Lactose intolerance can be diagnosed with a simple breath or blood test.

Milk Allergies:


A true food allergy is far less common than food intolerance. Unlike lactose intolerance, a milk allergy is the body’s adverse immune response to the proteins found in milk. There are two main types of milk allergy:

1) IgE-mediated milk allergy

This type of allergy is an almost immediate reaction that can occur within a few minutes of having cow’s milk. It can cause severe reactions, but more often the symptoms are mild. Sometimes anaphylaxis can result – a life-threatening allergic reaction causing swelling of the lips or mouth, difficulty breathing and collapse.

Other symptoms include:

  • rashes (hives)
  • diarrhoea
  • vomiting
  • stomach cramps
  • wheezing
  • runny nose
  • watering eyes

If you think you may be allergic to milk, it is important to speak to a health professional about it before taking action, as milk and dairy foods are an important part of our diets. They provide our bodies with essential nutrients including vitamins, minerals and proteins to assist bone growth and our overall health. Undertaking a milk-free diet means also eliminating butter, margarine, cheese, cream, yoghurt and ice cream, as well as a number of processed foods which can contain milk such as soups, processed meats, ready made meals, cakes, biscuits, baked goods, crisps and chocolate.

2) Non IgE-mediated allergy

Formerly referred to as cow’s milk protein intolerance, this condition is now known as non-IgE-mediated cow’s milk protein allergy. This type of allergy is different to IgE-mediated milk allergy and lactose intolerance. Although adults can develop this allergy, it is more commonly found in babies and children – it affects approximately 1 in 50 infants. Children with this allergy can experience symptoms from the first time they drink cow’s milk, but usually grow out of it by the time they start school. In rare instances, it can persist into adulthood.

Unlike an IgE-mediated milk allergy, the symptoms can take between a few hours to a few days after having milk to appear. Because of this delay, the allergy may go undiscovered for some time. Unfortunately, there is no easy test for this type of milk allergy.

Symptoms include:

  • eczema
  • diarrhoea
  • stomach cramps
  • vomiting

Rashes (hives) and/or trouble breathing do not occur with this type of allergic reaction.

If you suspect that you or your child may have a milk allergy, you should make an appointment with your doctor or health professional to obtain an official diagnosis before making any dietary changes. This is especially important for babies and young children; it is best to see an Allergy Specialist in order to make sure that the allergy is managed appropriately and that a healthy diet is maintained.

For more information and advice food allergies and intolerance, visit Allergy UK:

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3 Responses to Lactose Intolerance and Milk Allergies

  1. Pingback: Intolerances | Gluten-free in Ghana

  2. maybe it’s me but it seems like the page layout is a bit off center. it might be my laptop though. anyway educational blog. thank you Omar Yasseen

  3. Pingback: Casein & Milk – Immunity Details Change Minds « CorePsych

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