By Barbara McLaren

A person with Lactose Intolerance (LI) is unable to digest lactase, a natural sugar found in milk, causing lactose to remain undigested in the intestine.

What is happening?

Normally the Lactose enzyme breaks down lactose in the intestines to form the sugars glucose and galatose, which are easily absorbed through the intestine wall. If the enzyme is missing or reduced, unabsorbed lactose ferments in the large intestine, leading to the formation of gases, particularly methane gas, causing the symptoms of LI.

Dairy products from all mammals can cause LI, not just from cows. Buffalo and goats milk are a lot stronger than cows milk, which could explain the high incidence rate in some ethnic groups: up to 8 out of 10 Africans, Native Americans, Asian and Jewish people have LI. In this country 10% of the population are said to be sufferers.

Everyone with LI is affected differently, depending on the amount of the lactase enzyme they produce. This means that one person may be able to cope with a glass of milk in the morning before suffering any effects. Someone else may have LI so severely that even a lick of ice cream or a sip of milk causes major symptoms.

Symptoms

Symptoms often start very mild, but get gradually worse every time you have a reaction to dairy products. They include aggressive flatulence, nausea and/or vomiting, bloating gas, diarrhoea and stomach cramps causing severe pain. If you have undiagnosed lactase deficiency you may suffer from weight loss and malnutrition, caused be poor absorption of food (malabsorption). Malabsorption and malnutrition cause many health problems, too long to go into now, but I will write about them another time.

LI is another condition regularly misdiagnosed by the medical profession. People with the condition are wrongly classified as suffering from Irritable Bowel Syndrome (IBS). Many people suffer from symptoms without realising the actual cause of it. An intolerance to milk, a staple part of our diet is rarely suspected.

Many babies suffer from wind and colic. The cause of all the pain, crying and distress may be an inability to break down lactose (lactase deficiency). The fermentation of lactose in the bowels causes the formation of gases, including methane and carbon dioxide. These will cause the baby’s intestine to inflate, making it painful and very uncomfortable for him or her. Unfortunately, all too often LI remains undetected and the baby suffers unnecessarily.

There are two types of lactase deficiency

Primarily LI occurs when a child is born without the ability to produce lactase enzyme. It is congenital and very rare, making it permanent and lifelong. In Secondary LI damage to the mucous membrane of the small intestine is at fault, usually caused by another condition or illness. Young children suffering from gastro-intestinal infection or malnutrition are particularly vulnerable to this type of secondary deficiency. People with Coeliac Disease are also very vulnerable to Secondary LI as in both conditions the small intestine is damaged. An allergy to cow’s milk, certain drugs and gastro-intestinal surgery can also cause LI. It is Secondary LI that causes so many problems with people with ME.

Luckily LI is easy to treat, the symptoms being controlled by diet alone. Some milk products have been specially treated, having the lactose broken down. These are available over the counter, but tend to be very expensive. Some GP’s recommend taking lactase supplement in the form of liquid or capsules and can be added to drinks or taken before meals. They are reported to be very effective.

Barbara is a member of the ME North East Management Committee. She writes a regular column giving insights into various illnesses similar to and mixed up with ME. We get lots of positive feedback from these articles and we would like to thank Barbara for her continued efforts.

Information from Lactose Intolerance UK