When we eat, we expect to have nourishment and satisfaction, to nullify the hunger pangs. There are a lot of food allergies. In this piece, we will focus on lactose intolerance, distinguishing it from milk allergy.
Cow’s milk allergy and lactose intolerance are often confused with each other, but they are not the same. Cow’s milk is made up of lots of different components, for example proteins (such as casein and whey), milk sugar (called lactose) and fat. The allergic reaction happens because the immune system mistakes the proteins in cow’s milk to be a threat, when in fact they should be harmless. It then releases chemicals such as histamines and others – it’s these chemicals that trigger the signs and symptoms of an allergic reaction.
Lactose intolerance is triggered by the lactose sugar in cow’s milk. In people with lactose intolerance, the digestive system can’t fully digest this milk sugar, because it doesn’t make enough of the lactase enzyme. So instead of being digested and absorbed, the lactose stays in the gut and feeds the gut bacteria, which release acids and gases that cause the symptoms of lactose intolerance. In some cases, people can develop lactose intolerance when their gut becomes damaged through illness, surgery or certain medications (this is called secondary lactase deficiency). In these cases, the lactose intolerance can be temporary or permanent. It can sometimes develop after an episode of gastroenteritis.
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. Symptoms of lactose intolerance usually develop within a few hours of consuming food or drink that contains lactose. They may include:
• flatulence (wind)
• bloated stomach
• stomach cramps and pains
• stomach rumbling
• feeling sick
The severity of your symptoms and when they appear depends on the amount of lactose you’ve consumed. Some people may still be able to drink a small glass of milk without triggering any symptoms, while others may not even be able to have milk in their tea or coffee.
The symptoms may be similar to the following, and it is always best for you to see your doctor, as soon as possible, to give an accurate diagnosis.
• 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 doctor thinks you have lactose intolerance, they may suggest avoiding foods and drinks containing lactose for two weeks to see if your symptoms improve.
It’s important to visit your doctor , if you think you or your child may have lactose intolerance, as the symptoms can be similar to other conditions. Keep a diary of what you eat and drink, and what symptoms you experience. Let your doctor know if you notice any patterns, or if there are any foods you seem particularly sensitive to. Your doctor may suggest trying to remove lactose from your diet for two weeks to see if it helps to relieve your symptoms. This will provide further evidence of whether you’re lactose intolerant.
Some of the main tests that may be used are described below.
Hydrogen breath test
A hydrogen breath test is a simple way of determining if you may be lactose intolerant. You’ll be asked to avoid eating or drinking during the night before the test. When you arrive for the test, you’ll be asked to blow up a balloon-like bag. This sample of your breath will be tested to find out how much hydrogen is present, measured in parts per million (ppm).
You’ll then be given a drink of lactose solution and your breath will be tested every 15 minutes over the next few hours to see if the level of hydrogen changes. If your breath contains a large amount of hydrogen (more than 20ppm above your baseline) after consuming the lactose solution, it’s likely that you’re lactose intolerant. This is because lactose intolerance can cause the bacteria in the colon (large intestine) to produce more hydrogen than normal.
Lactose tolerance 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.
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.
Small bowel biopsy
A small bowel biopsy is rarely used to diagnose lactose intolerance. However, it may be carried out to see if your symptoms are being caused by another condition, such as coeliac disease.
What causes 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 life long, but cases in young children are often caused by an infection in the digestive system and may only last for a few weeks.
Lactose intolerance is usually the result of your body not producing enough lactase.
Lactase is an enzyme (a protein that causes a chemical reaction to occur) normally produced in your small intestine that’s used to digest lactose. If you have a lactase deficiency, it means your body doesn’t produce enough lactase.
After eating or drinking something containing lactose, it passes down your oesophagus (gullet) into your stomach, where it’s digested. The digested food then passes into your small intestine. The lactase in your small intestine should break lactose down into glucose and galactose (other types of sugar), which are then absorbed into your bloodstream. If there isn’t enough lactase, the unabsorbed lactose moves through your digestive system to your colon (large intestine). Bacteria in the colon ferment (break down) the lactose, producing fatty acids and gases such as carbon dioxide, hydrogen and methane. The breakdown of the lactose in the colon, and the resulting acids and gases that are produced, cause the symptoms of lactose intolerance such as flatulence and bloating.
lactose intolerance is more common in people of Asian or African-Caribbean descent.
Lactose intolerance can develop at any age. Many cases first develop in people aged 20 to 40, although babies and young children can also be affected.
Is it an allergy?
Lactose intolerance isn’t the same as a milk or dairy allergy. Food allergies are caused by your immune system reacting to a certain type of food. This causes symptoms such as a rash, wheezing and itching.
If you’re allergic to something, even a tiny particle can be enough to trigger a reaction, while most people with lactose intolerance can still consume small amounts of lactose without experiencing any problems (although this varies from person to person).
Treating lactose intolerance
There’s no cure for lactose intolerance, but limiting your intake of food and drink containing lactose usually helps to control the symptoms. Depending on what dairy products you’re able to eat, you may also require additional calcium and vitamin D supplements to keep your bones strong and healthy. In some cases, your GP may refer you to a dietitian for further advice. In addition to dietary changes, lactase substitutes may also be helpful. These are drops or tablets you can take with your meals or drinks to improve your digestion of lactose.
Complications of lactose intolerance
Milk and other dairy products contain calcium, protein and vitamins such as A, B12 and D. Lactose also helps your body absorb a number of other minerals, such as magnesium and zinc. These vitamins and minerals are important for the development of strong, healthy bones. 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.