Symptoms usually appear within one to two hours after eating or drinking foods containing lactose. The severity of the symptoms varies depending upon the amount of lactose ingested and the amount of lactose that each person can tolerate. Symptoms may include gas and bloating, abdominal cramps, nausea, and diarrhea. Lactose intolerance should be distinguished from a milk allergy. With an allergy to cow milk protein, there is usually rhinitis and dermatitis, as well as the abdominal distress and gas. The milk allergy normally occurs in the first few months of life and may disappear by age three.
Children after the age of 2 years may produce insufficient lactase for digestion of lactose. Among adults in North America, some measure of lactose maldigestion occurs in about one-fifth of whites, one-half of Hispanics, four-fifths of African Americans, and over 80 percent of Asian Americans.
Milk and other dairy products are not the only food sources of lactose. It is often added to prepared foods, sometimes in amounts that are not insignificant. Food products that may contain lactose include breads and other bakery products, candies and some snacks, processed breakfast cereals, instant potatoes, soups, sauces, and breakfast drinks, margarine, mayonnaise and salad dressings, pancake mix, biscuits, cakes and cookies. Some products such as nondairy creamers and nondairy whipped toppings often contain whey, or dry milk solids and other ingredients derived from milk, so that these products will also contain lactose. Persons who are intolerant to even small amounts of lactose should learn to carefully read food labels to identify all products that contain lactose. Lactose is also used as a base for more than 20 percent of prescription drugs and six percent of over-the-counter medicines. Lactose may also be used as a carrier for vitamin pills.
Lactose intolerance is fairly easy to treat. Children and adults should cut down the use of lactose-containing foods or try to avoid dairy foods altogether. The degree of lactose avoidance will depend upon the level of lactose tolerance of the person, since individuals differ in the amounts of lactose they are able to handle before experiencing symptoms.
Different dairy products may also vary in their ability to cause symptoms. Whole milk is better tolerated than skim milk, since the fat delays gastric emptying. Milk is usually better tolerated when consumed with a meal. Cheese and ice cream have less lactose than milk and hence cause fewer symptoms. Normally, aged cheeses (such as Swiss and cheddar cheese) are handled better than softer cheeses. Yogurt, but not frozen yogurt (or ice-cream), can normally be tolerated by many persons with lactose intolerance. Fruit- flavored yogurt is not tolerated as well as plain yogurt. Enzyme preparations that help digest lactose are available today to enable a person to consume dairy foods without symptoms.
Non-dairy products are also growing in popularity amongst those wishing to cut down on their saturated fat and cholesterol intake and those who have a fear of milk-borne diseases. Acceptability of a non-dairy beverage (made from soy, rice, oats, almond or potato) is usually determined by the color, taste, consistency and price of the product. However, many of these beverages have little, if any, fortification. It is well to remember that only those fortified with substantial levels of calcium, and vitamins D, B2 and B12 (at least 20-30% of the daily values) should be considered a reasonable substitute for milk. Label reading is important since formulas change with time.
A few points should be noted by those using non-dairy beverages for cooking purposes. Soy beverages and others that are highly fortified with calcium carbonate tend to curdle at high temperatures. Consistency may be unpredictable. Most instant puddings do not set when a non-dairy beverage is substituted for dairy milk. When making gravies, a higher percentage of thickening agent (starch) needs to be used. As a general rule, soy-based beverages have a thicker, richer, and creamier texture than grain or nut based beverages. Rice-based beverages have a lighter, sweeter flavor, and for many people, more closely imitate the flavor of dairy milk. Nut-based beverages are better for desserts of all kinds.
Winston J. Craig is Professor of Nutrition at Andrews University, Berrien Springs, Michigan. All rights reserved © 2011 AnswersForMe.org. Click here for content usage information.