Lactose Intolerance


What is Lactose Intolerance? 

Lactose intolerance is a common digestive problem where the body is unable to digest lactose, a type of sugar mainly found in milk and dairy products. Lactose intolerance is the inability to absorb lactose – the predominant sugar in milk – into the digestive system. The common foods which contain lactose include the following 

  • Milk, butter, margarine, fermented milk products, yoghurt and cheese, ice cream etc. 
  • Milk powder.
  • Bread and other baked goods – read the label to check.
  • Prepared foods such as certain pizzas, certain soups – again, read the label.
  • Milk Chocolate 
  • Sour Cream, certain dressings, certain sauces containing milk - read the label. 


Lactose Intolerance Continued 

Lactose intolerance is when someone has difficulty absorbing and digesting lactose, a type of sugar found in milk. Lactose intolerance is associated with undiagnosed coeliac disease and is usually temporary. Most people with coeliac disease do not have a problem with lactose intolerance once they have been following the gluten-free diet for some time.

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What are the causes of lactose intolerance? 

The body digests lactose using a substance called lactase. This breaks down lactose into two sugars called glucose and galactose, which can be easily absorbed into the bloodstream. People with lactose intolerance don't produce enough lactase, so lactose stays in the digestive system where it's fermented by bacteria. This leads to the production of various gases, which cause the symptoms associated with lactose intolerance. Depending on the underlying reason why the body isn't producing enough lactase, lactose intolerance may be temporary or permanent. Most cases that develop in adults are inherited and tend to be lifelong, but cases in young children are often caused by an infection in the digestive system and may only last for a few weeks. 


What are the symptoms of lactose intolerance? 

Symptoms of lactose intolerance usually develop within a few hours of consuming food or drink that contains lactose. They may include:

  • flatulence (wind)
  • diarrhoea
  • bloated stomach
  • stomach cramps and pains
  • stomach rumbling
  • feeling sick/ nausea

The severity of your symptoms and when they appear depends on the amount of lactose you've consumed. 


When to seek medical advice for lactose intolerance 

The symptoms of lactose intolerance can be similar to several other conditions, so it's important to see your GP for a diagnosis before removing milk and dairy products from your diet.

For example, the symptoms above can also be caused by:

  • irritable bowel syndrome (IBS) – a long-term disorder that affects the digestive system
  • milk protein intolerance – an adverse reaction to the protein in milk from cows (not the same as a milk allergy)

If your GP thinks you have lactose intolerance, they may suggest avoiding foods and drinks containing lactose for two weeks to see if your symptoms improve. 


Health risks assosciated with lactose intolerance 

If you're lactose intolerant, getting the right amount of important vitamins and minerals can prove difficult. This may lead to unhealthy weight loss and put you at increased risk of developing the following conditions:

  • Osteopenia – where you have a very low bone-mineral density. If osteopenia is not treated, it can develop into osteoporosis.
  • Osteoporosis – where your bones become thin and weak. If you have osteoporosis, your risk of getting fractures and broken bones is increased.
  • Malnutrition – when the food you eat doesn't give you the nutrients essential for a healthy functioning body. If you're malnourished, wounds can take longer to heal and you may start to feel tired or depressed.


Lactose Intolerance Test 

In a lactose tolerance test, you'll be given a drink of lactose solution and a blood sample will be taken from your arm using a needle. The blood will be tested to see how much glucose (blood sugar) it contains. If you're lactose intolerant, your blood sugar levels will either rise slowly, or not at all. This is because your body is unable to break down the lactose into glucose.

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Milk Tolerance Test 

In a milk tolerance test, you'll be given a glass of milk (about 500ml) and your blood sugar levels will be tested. If your blood sugar levels don't rise after drinking the milk, you may be lactose intolerant. 


Lactose Free Foods And Drinks 

There are a number of alternative foods and drinks available in supermarkets to replace the milk and dairy products you need to avoid.

Food and drinks that don't usually contain lactose include:

  • soya milks, yoghurts and some cheeses
  • milks made from rice, oats, almonds, hazelnuts, coconut, quinoa, and potato
  • foods which carry the 'dairy-free' or 'suitable for vegans' signs
  • carob bars


Keywords related to lactose intolerance 

Lactose is the main carbohydrate in milk products, and comprises a disaccharide consisting of glucose and galactose.

Lactase is an enzyme located in the small intestine that hydrolyses lactose to its components: glucose and galactose.

Lactase deficiency or Lactase non-persistence is a decreased activity of lactase in the small intestine.

Lactose maldigestion occurs as a result of lactase deficiency or non-persistence. Lactose cannot be fully hydrolysed and absorbed into the portal circulation from the small intestine but passes into the colon.

Lactose intolerance comprises adverse gastrointestinal symptoms caused by lactose maldigestion.


What should I eat if i am lactose intolerant? 

  • Soy, almond, rice and coconut milk 
  • Sardines 
  • Salmon 
  • Collard greens 
  • Kale 
  • Broccoli 
  • Spinach 
  • Fatty fish such as tuna mackerel and salmon 
  • Fish liver oil 
  • Calcium fortified orange juice 
  • Almonds