Some people cannot drink or eat milk or milk products because they cannot tolerate lactose, the main sugar in milk. (In fact, milk sugar is another term for lactose.) The reason some people cannot tolerate lactose is that their bodies are unable to break it down into a form that can be absorbed by the small intestine. This inability is due to insufficient lactase, the enzyme which breaks down lactose in their intestines. As a result, undigested lactose is left in the intestines, where it comes into contact with the bacteria naturally present there. This can cause a number of unpleasant digestive symptoms.
People at Risk
Children are at risk for developing lactose intolerance at an early age; roughly 70 percent of the world’s population of children begins to lose the ability to make the enzyme lactase after being weaned. The prevalence of the condition in the general population, on the other hand, is unknown. However, it is considered to be overestimated. Only one out of every five people who suspect they have lactose intolerance actually have symptoms after drinking a single glass of milk.
Symptoms Of Lactose Intolerance
Lactose intolerance is characterized by:
- abdominal bloating
- stomach cramps
The frequency and severity of the symptoms seem to be dose-related. In general, the larger the amount of lactose consumed, the greater the risk of more frequent and severe symptoms.
The biggest concern about lactose intolerance is not the condition itself so much as the risk that people will stop consuming milk and milk products in order to avoid unpleasant symptoms. Stopping milk consumption would jeopardize the intake of essential nutrients that milk and milk products supply, such as:
- vitamin A
- vitamin D
Many people with lactose intolerance can manage to consume enough products that are rich in these nutrients to meet recommended requirements, through various dietary strategies such as consuming lactose-containing foods in smaller amounts or using lactose-reduced products.
If you are one of the few people who truly cannot tolerate any dairy products at all, it is very important to make sure you get enough calcium from other sources, such as calcium supplements and non-dairy, calcium-rich foods. The following are all good sources of calcium.
- salmon with bones
Just about any ordinary diet contains lactose intolerance “triggers” that people with this condition need to watch out for. Keep in mind, however, that some lactose-containing foods have more lactose in them than others. If you know the lactose content of various foods, you will find it much easier to make decisions about whether you can consume any of them, and in what amounts, without suffering adverse effects.
Lactose Content of Selected Foods
|Whey, dry||1 oz.||19-21|
|Yogurt, low-fat||8 oz. (1 cup)||5-19|
|Milk||8 oz. (1 cup)||9-14|
|Yogurt, whole-milk||8 oz. (1 cup)||10-12|
|Buttermilk||8 oz. (1 cup)||9-12|
|Milk, acidophilus skim||8 oz. (1 cup)||11|
|Ice milk||6 oz. (3/4 cup)||8|
|Ice cream||6 oz. (3/4 cup)||3-8|
|American pasteurized processed cheese||1.5 oz.||0-6|
|Ricotta cheese||4 oz. (1/2 cup)||0-6|
|Velveeta cheese||1.5 oz.||4|
|Cottage cheese||4 oz. (1/2 cup)||0-4|
|Orange sherbet||6 oz. (3/4 cup)||1-2|
|Half and half||2 Tbsp.||1|
|Sour cream||2 Tbsp.||1|
|Hard cheese (most)||1.5 oz||1|
|Cream cheese||1.5 oz.||0-1|
|Butter or margarine||1 Tbsp||0|
The presence of lactose in certain foods is not always clear-cut. When reading food labels, watch for these words and phrases. They may indicate the presence of lactose in the product.
- milk solids
- nonfat milk solids
- sweet cream
- sour cream
- malted milk
The following are foods that may contain lactose.
- chocolate drink mixes
- cold cuts
- cream soups
- dry cereals
- frozen breaded fish and chicken
- hot dogs
- prepared and processed foods
- salad dressing containing milk or cheese
- sugar substitutes
Dietary Management For Lactose Intolerance
Even though low lactase levels generally will persist in people who have them, problems with lactose intolerance often can be avoided through dietary strategies. For some people, drinking or eating smaller amounts of lactose-containing foods may prevent symptoms. For others, gradually increasing the intake of lactose may improve tolerance. Many people find that simply consuming lactose with a meal or solid food minimizes problems.
Here are some important facts that can help you establish effective dietary strategies for specific kinds of foods.
- Whole milk is better tolerated than lower-fat milk.
- 1 percent chocolate milk may be better tolerated than regular low-fat milk.
- Cheese may be better tolerated than milk due to a lower lactose content.
- Cheese is also well-tolerated because during the cheese-making process, most of the whey is removed (and the lactose with it). In mature, ripened cheese, lactose disappears entirely within three to four weeks.
- Specific kinds of cheese which you can reasonably expect to tolerate fairly well include cheddar, Colby, Swiss, Parmesan and cottage cheese.
- Like cheese, ice cream has less lactose than milk and may therefore be tolerated better.
- Yogurt that is labeled “active yogurt culture” or “live and active cultures” is generally well tolerated.
- Most U.S. yogurt has an appreciable amount of lactose in it, but it seems to be better digested than the lactose in milk.
- Frozen yogurt, as well as yogurt containing fruits, sweeteners or flavorings, will generally not be digested as well as plain yogurt.
- Frozen yogurt and ice cream, because of their solids and fat content, are tolerated to about the same degree.
- Lactose-reduced milks (low-fat, skim, nonfat and calcium-fortified chocolate) with 70-100 percent of their lactose hydrolyzed are widely available today.
- Lactose-reduced cottage cheese, pasteurized processed cheese and ice cream are also available in some markets.
- These products increase the cost of milk or milk products and may not be necessary for persons who can tolerate the lactose equivalent of a cup of milk per serving.
- If you cannot tolerate a small serving of milk at all, you can make lactose-reduced milk at home by incubating it with a lactase preparation overnight. Adding 5-10 drops of a liquid lactase preparation to a cup of milk hydrolyzes 70-100 percent of the lactose.
Oral enzyme replacements
- Taking an oral enzyme replacement tablet at the beginning of a meal improves tolerance to lactose in milk or foods. Dairy Ease, Lactaid and Lactrase are names of some of the capsules available.
- Be sure that any oral enzyme replacement you take has sufficient acid stability to withstand digestion by the stomach.
- If you can tolerate the lactose equivalent of a cup of milk per serving, you may find it more convenient and less expensive to just drink a small amount of milk with your meals than to take an enzyme replacement.