A normal function of the digestive system is to break down the food we eat into smaller pieces. This is achieved with the use of enzymes that are present in our saliva, stomach and intestines. This process of breaking down the food aids the body in absorbing essential nutrients, proteins and carbohydrates.

One such enzyme is called lactase. This enzyme is needed to breakdown lactose, which is the sugar in milk. Lactose is actually made up of two different sugars, which are chemically joined together. One separated, these sugars, which are called glucose and galaxies, can be absorbed into the bloodstream. Lactase enzymes are generally found in the jejunum, which in normal terms is the beginning of the small intestine. These enzymes perform but one function – breaking down lactose.

People with a condition known as lactose intolerance have a shortage of the enzyme lactase. As there is a shortage of lactase, the digestive system is unable to properly separate these sugars, which effectively means that some milk remains undigested inside the intestines, causing discomfort, bloating, wind and even diarrhea. Lactose intolerance is said to be among the most common disorders in the world, with nearly 50% of all humans developing some degree of intolerance at some point in their lives.

Although one of the most important nutrients for infants, supplying up to half of the total energy requirement of a newborn baby, it is believed that lactose has no special function or importance for adults. This had led some people to suggest that humans were never designed to drink milk after being weaned.

Many babies suffer from sensitivity to lactose at one time or another, and are subsequently given lactose free formula. Due to the importance of lactose in the supply of energy to infants, any newborn baby that is fed using a lactose free formula must also receive extra energy to replace that lost by the omission of lactose in the lactose free formula.

Lactose has excellent physiological properties such as good texture and an ability to bind water. For this reason it is used extensively in the food industry and can be found in bread, sausages, and even sweets. The next time you are in the supermarket, stop and read the ingredients in the sweets aisle. I’m sure you’ll see many products containing lactose.

For this reason people with intolerance to lactose must be very selective in their diet as lactose is found in some of the most unlikely foods.

There have been some scientific studies carried out in search of a treatment for sensitivity to lactose, however to date these treatments vary in effectiveness from patient to patient and no definite solution has been discovered.

Lactose is a sugar or carbohydrate found in milk and other dairy products. A person is intolerant to lactose when they have difficulty digesting milks sugars from dairy products. Normally, enzymes called lactase found in a person’s digestive system are able to break down these sugars in to simpler components. However when insufficient lactase is produced, the body is unable to break down these sugars, causing digestive problems which may result in abdominal pain and diarrhoea. This is what is known as lactose intolerance of lactase deficiency.

The majority of mammals cease to produce lactase after they are weaned; however humans continue to produce it throughout life.

Many babies who have irritability to some foods are wrongly diagnosed and are subsequently weaned onto a lactose free formula, however true lactose intolerance in babies is actually very rare.

The more common variety of lactose intolerance develops after weaning. This is known as secondary lactose intolerance, and may be brought about by such things as a bout of gastroenteritis, where the lining of the stomach is weakened. This is usually a temporary condition that will improve as the lining of the gut strengthens and heals.

Interestingly, it is rare for Caucasian people to suffer from this condition. It is far more common in people from Africa, Asia and the Middle East. According to one study “up to five per cent of Caucasians and up to 75 per cent of non-Caucasians living in Australia are lactose intolerant”.

The basic symptoms of lactose intolerance are abdominal pain and swelling, flatulence and diarrhoea. Many people who have a lactose intolerance do in fact have some degree of tolerance, meaning they are able to eat some foods containing lactose. It is when these foods are consumed to an excess that the digestive system cannot cope and the symptoms appear.

The wind, bloating and pain associated with intolerance to lactose is actually due to a fermentation process which takes place in the intestines. The enzyme lactase breaks down the lactose (milk sugar). This changes the sugar into glucose and galactose – compounds which the intestine is able to absorb.

If there is not enough lactase in the system to break down these milk sugars, bacteria in the system begin to break down the excess, which is where the fermentation process commences. Undigested lactose is pushed along the intestines without water being removed, which results in diarrhoea.

There are four main causes of intolerance to lactose. These are:

• Congential – The main cause. Your genes dictate that you produce less lactase than normal.
• Iron deficiency – A diet lacking in iron may interfere with lactose digestion and absorption.
• Gastroenteritis – If you have Gastro, your intestines my be stripped of lactase for a while. As the lining repairs itself, your lactase levels should return to normal.
• Parasitic infection – May reduce lactase levels temporarily.

In summary, lactose is a milk sugar which is broken down by lactase in the small intestine. Lactose intolerance is caused by an inability to digest these milk sugars, as a result of a depleted amount of the enzyme lactase. Symptoms of lactose intolerance include bloating, gas and diarrhoea.