Overview:
Dairy allergy, or milk allergy, refers to any allergic reaction caused by a component of cow's milk. The three components of cow's milk that cause dietary reactions are casein protein, whey protein, and lactose sugar. Casein and whey are considered more likely to cause true allergies, while lactose causes a well-known intolerance in many adults (and some children) due to the body's lack of an enzyme known as lactase.
Cross-Reactions:
Similar components to cow's milk are found in the milk of other ruminants, including goats and sheep, so any patient with a dairy allergy who is considering using other animal milk as a substitute for cow's milk should talk to their allergist before proceeding.
Symptoms:
Dairy allergies may appear with a wide variety of symptoms, including hives (urticaria), eczema, chronic congestion, and diarrhea. Lactose intolerance, like many other dietary intolerances, causes gastrointestinal symptoms, such as bloating, cramping, and diarrhea. As always, if you suspect you or your child has a food allergy, contact your physician.
Preventing Dairy Allergies:
Because dairy allergies are especially prevalent among babies, parents with atopic families - that is, families with a history of severe allergies - should discuss feeding options with their pediatricians before delivery, if at all possible. There is some evidence that nursing exclusively until six months and delaying the introduction of solid foods until that time can help prevent the development of allergies.
Special Concerns for Formula-Feeding Infants:
Bottle-feeding families have a few options for feeding infants who either have dairy allergies or are considered to be at high-risk for developing them. The preferred option, especially in families with a history of eczema, is formula that is hydrolyzed, meaning that the proteins have been processed to break them down. These formulas are often preferred to soy because soy itself is a common allergen and hydrolyzed formula is tolerated by more babies. Your doctor will help you select the appropriate formula. Insurance can help defray the high costs of hydrolyzed formula. Some types are only available by prescription.
Preventing Lactose Intolerance Symptoms:
Lactose intolerance symptoms can be prevented, at least temporarily, by replacing the lactase enzyme the body lacks. This is done in one of two ways: through dietary supplements, which are available over-the-counter, or by adding lactase directly to dairy products. The latter is how lactose-free milk is made. When lactase is added to milk, it breaks down the lactose in the milk into the simple sugars glucose and galactose, which are easier to digest. Lactose-free milk tastes a little sweeter because of this process (your body tastes the simple sugars more strongly), but is otherwise identical to any other milk.
Foods Containing Dairy Products:
Cheese, butter, yogurt, cream, kefir, sour cream, and ice cream, unless specifically formulated to be dairy-free, always contain milk. Milk is also present in many types of processed food. Processed foods that are likely to contain dairy products include chocolate, salad dressings, pastries, snack foods with butter or cheese flavorings (even if they're artificial), soups, and even canned tuna and deli meats. As with any food allergy, never eat any processed food unless you have read the label, and always be aware of cross-contamination risks from utensils or surfaces where dairy products may have been prepared.
Dairy Products and Labeling Laws:
Dairy is one of the eight most common allergens in the United States, and as such, current food labeling laws require that the presence of milk be clearly marked on ingredient labels. However, it's best to learn the myriad names dairy products appear on in labels. While FDA laws require that the presence of milk be marked in plain English, it's safest to rely on that in conjunction with your own knowledge of dairy-containing ingredients. This wallet-sized list includes both a collection of aliases for milk and a partial list of foods that are particularly likely to include dairy products.
Living with Dairy Allergies and Lactose Intolerance:
You'll find substitutes for milk products in many supermarkets and health-food stores. Always check these for the presence of dairy, however; some may include traces of milk and thus be unsuitable for someone with allergies. With that caveat, try the many milk substitutes on the market for baking, drinking, and cooking. Soy milk, rice milk, and nut milks are but a few of the varieties available, and each has different properties. Rice milk is low in protein (so it acts quite differently than cow's milk in baking) but has a mild taste; in its vanilla flavor it is delicious on cereal and good for drinking plain. Soy milk and nut milks have a stronger flavor and can work well in baked goods.
Milk has a somewhat outsized reputation as a nutritional powerhouse. However, with planning, you can easily replace the nutrients in milk. Be especially aware of calcium, protein, and vitamins A, D, E, and K, which are found in abundance in dairy products.
Other dairy-free products (as of this writing; check labels in case recipes have changed) you're likely to find at your local supermarket include:
- Tofutti Sour Supreme, Better than Cream Cheese, and Nondairy Frozen Desserts
- Imagine Creamy Soups, all of which are nondairy (their seafood bisques, however, do contain dairy)
- Amy's Kitchen frozen and ready-to-eat foods, which include over seventy dairy-free entrees and snacks, from pizza to pot pies
- Cherrybrook Kitchen baking mixes
You'll find an even wider variety of dairy-free products at natural foods stores, co-ops, and specialty chains like Whole Foods Market and Fresh Market. There are also online dairy-free retailers like The Wheat- and Dairy-Free Supermarket.
Sources:
Crittenden R.G., Bennett L.E. "Cow's Milk Allergy: A Complex Disorder." J Am Coll Nutr. 2005 Dec;24(6 Suppl):582S-91S. (Note: link is to abstract only.}
Groenewald, M. Allergy Society of South Africa.
Høst, A., Halken, S. Allergy. 2004 Aug;59 Suppl 78:45-52.
McGee, Harold. "Milk Biology and Chemistry." On Food and Cooking: The Science and Lore of the Kitchen. First revised ed. New York: Scribner, 2004. 14-21.
