lactoseintollerence homefamily health Virgin Media

Many people will have come across the term "lactose intolerance", perhaps without realising that it affects the majority of the world's population. Even in the UK alone, lactose intolerance is a surprisingly widespread condition. It is estimated that between 2% and 15% of the UK's white population and a staggering 95% of Asians and 75% of Afro-Caribbeans in the country are lactose intolerant. So what exactly is it and how does it affect people?

Lactose is a type of sugar that is found in milk, making up to around 2% and 8% of its solids. Many common foodstuffs containing milk will therefore also contain some lactose. When we eat lactose, it is broken down by an essential enzyme called lactase during the digestive process. Lactase is normally found in the intestine but some people do not produce enough of it and therefore cannot break down and absorb the lactose - in other words, they have a lactose intolerance.

The undigested lactose remains in the large intestine and is fermented by bacteria creating very uncomfortable abdominal symptoms. The symptoms can include nausea, stomach cramps, bloating, gas and diarrhoea, and can occur up to two hours after drinking milk.

It should be pointed out that lactose intolerance is not the same as a milk allergy. With a milk allergy, it tends to be the protein in milk that causes the problem, whereas with lactose intolerance it is specifically the sugar in milk.

Although the symptoms affecting the digestive system are similar, milk allergy can also cause skin reactions and in very rare cases life-threatening anaphylactic attacks - this is not the case with lactose intolerance.

Lactose intolerance mostly tends to affect adults, since the production of the enzyme lactase slows down or even stops in adulthood. In some cases, it can also affect those who have had stomach surgery, those who are suffering coeliac's disease, or it can strike after a bout of diarrhoea, at least until the underlying condition has been treated. The severity of the symptoms can vary a great deal - whereas some people might be able to have a splash of milk in their tea, it may result in discomfort for others.