Lactose intolerance?

Lactose intolerance is the inability to digest significant amounts of lactose, the major sugar found in milk. Lactose intolerance is caused by a shortage of the enzyme lactase, which is produced by the cells that line the small intestine. Lactase breaks down milk sugar into two simpler forms of sugar called glucose and galactose, which are then absorbed into the bloodstream.

If you do not produce enough lactase, lactose skips the usual digestive process, only partially breaking down in the intestines. This fermentation causes the symptoms associated with lactose intolerance. The undigested lactose is sent along the intestinal tract, water is not removed from the faecal matter and results in diarrhea.

What causes lactose intolerance?

It is estimated that about 70% of the world's population and about 10% of Australians can not drink milk or eat dairy products without getting an upset stomach (3). Lactose Intolerance can be genetic and happens most often in people of African, Asian and Mediterranean descent (2). There is several different cause of lactose intolerance who are not of the above decent; Primary lactase intolerance is relatively common in adults and is cause by a slow decrease in the body’s production of lactase. Secondary lactase intolerance occurs when you injure your small intestines or have certain digestive diseases such as celiac disease, inflammatory bowel disease and Crohn’s diseases. These diseases tend to lower the amount of lactase you produce. Premature babies are also prone to lactose intolerance as lactase levels do not increase until the end of the third trimester (5).

What are the symptoms of lactose intolerance?

The following symptoms range form mild to severe depending on the degree of lactase deficiency, amount of lactose sugar consumed, age and ethnicity of the person. Symptoms begin anywhere from 30 minutes to two hours after consuming lactose and include:

• Nausea
• Abdominal pains and swelling
• Bloating
• Flatulence
• Diarrhea
• Vomiting
• Weight loss
• Malnutrition (especially in babies)

The above symptoms are often confused with either irritable bowel syndrome or milk allergies (5); hence it is essential if you think you are lactose intolerant to see your doctor for testing.

Diagnosis and tests for lactose intolerance

The most common tests used to measure the absorption of lactose in the digestive system are the lactose tolerance test, the hydrogen breath test and the stool acidity test. These tests can be completed at a doctor’s office or as an out patient at the hospital. You can also do a home self-test procedure, which involves removing foods with lactose to see if the symptoms improve. If your symptoms reappear when you re-introduce, then lactose intolerance is most likely the cause, however to be sure please consult with your doctor.

What is hidden lactose?

Even though milk and foods make from milk are the only natural sources of lactose, it is often added to manufactured foods, affecting people with a very low tolerance to lactose. These products include:

• bread and other baked goods
• processed breakfast cereals
• instant potatoes, soups, and breakfast drinks
• margarine
• lunch meats (other than kosher)
• salad dressings
• scrambled eggs
• lollies and other snacks
• mixes for pancakes, custards, cheese sauce, biscuits, and cookies
• powdered meal-replacement supplements
• muesli bars

Therefore it is important you read the ingredients list of all food products you consume, as even products labeled non-diary, such as powdered coffee creamers, may actually include ingredients derived from milk products. When reading food labels don’t only look for milk and lactose, also look for whey, curds, milk by-products, milk sugar, dry milk solids and non-fat dry milk powder. If any of the above words are present in the ingredient list, the product may contain lactose.

Treatments for lactose intolerance

Treatments vary from completely avoiding foods containing lactose (which is not easy) to buying treated food. Unfortunately no treatment can improve the body’s ability to produce lactase, but symptoms can be controlled through your diet.

They are currently doing experiments using gene therapy which are very successful. Scientist have discovered rats are able to digest lactose after been administered gene therapy orally in liquid form (5), however while we wait for human gene therapy people with lactose intolerance need to be able to manage this condition.

You may be surprised that even if you are lactose intolerant, you may be able to handle small amounts of lactose. Try not to give milk products up entirely as they are very nutritious and good sources of calcium. Yoghurt and cheese, especially cottage and swiss cheese, tend to be tolerated easier then milk and full fat milk is tolerated easier than low fat as the higher fat content slows down the journey of the milk through your intestines, allowing the lactase enzyme more time to break down the milk sugars. Spreading lactose containing foods over the day, instead of eating a lot in one meal should ease the symptoms and try consuming products in moderate quantities, as most people with this condition can tolerate the amount of lactose found in:

• Half a cup of full fat milk per day
• Three quarters of a cup of ice cream
• Three quarters of a cup of yogurt
• Three quarters of a cup of unripened cheese like cottage or ricotta (4)

It is important you find your limit, and the best way to achieve this is through trial an error. For those who react to small amounts of lactose, lactase enzymes are available from pharmacies. You can get liquid drops, such as Lact-easy drops which can be added to normal cow’s milk to reduce the lactose content. Alternatively there are chewable tablets, such as Lactaid tablets which you consume with the first bite or drink of lactose containing food or beverages. No prescription is required however I would recommend consulting your doctor or dietitian before using these above products.

A dietary concern with lactose intolerant people is there daily intake of calcium, as the human body needs this mineral every day. Calcium is not just used to keep your bones and teeth strong over time, it also ensures proper functioning of muscles and nerves; Calcium even helps your blood to clot. If you are unable to tolerate diary products, non-dairy foods high in calcium include:

• dark green vegetables, especially Asian greens
• fish with soft edible bones, for example salmon and sardines
• Soy milk fortified with calcium
• Fortified cereal and fruit juices
• Pinto beans
• Tahini and some brands of tofu
• Canned tuna
• Sesame seeds
• Brazil nuts and almonds

Using the table below to compare the calcium content of one cup of raw broccoli to one cup of plain yogurt, you can clearly see that you need to consume many cups of broccoli to obtain the recommended calcium intake of 800 mg per day (this daily figure is higher if you are a child, pregnant, lactating or post-menopausal).

Spinach and rhubarb also contain reasonable amounts of calcium, however they contain substances called oxalates, which inhibit the absorption of calcium; hence the body is unable to use calcium and it gets excreted in your urine (1). If you feel your daily calcium intake is inadequate, please consult with a doctor or health professional before consuming tablets, as taking vitamins and minerals of the wrong kind or in the wrong amounts can be very detrimental to your health.

Therefore even though Lactose intolerance is common, it is not a threat to good health. If you have trouble digesting lactose, you need to discover which diary products and other foods you can eat without side effects and which ones you need to avoid. A carefully chosen diet is the key to reducing symptoms.

For any further information don’t hesitate to contact the Rachel Clark, Nutritionist at Beleura Sports and Spinal Centre.