The World's Healthiest Foods

I think I am allergic to dairy products. How can I find out for sure?


Many people find that they are sensitive to dairy products, experiencing a host of symptoms including flatulence (gas), diarrhea, skin rash and fatigue when they consume milk and other dairy products. Yet, because adverse reactions to foods don't necessarily occur right after the consumption of these foods, sometimes occurring hours or even days after the food has been eaten, many people are uncertain as to which specific food may have triggered the unforeseen and unwanted symptoms. Additionally, there are so many "hidden" sources of dairy-derived ingredients that it takes a concerted effort to figure out whether you may be sensitive to dairy. Therefore, your concern that you may have a sensitivity to dairy products and your questioning as to how to be certain are both right on the mark. The following information should help to clarify this issue for you.

Dairy reaction aren't easy to identify

Finding out for sure about a dairy allergy is a lot more complicated than most people think! Since "dairy" is just another word for "cow's milk," anything made from cow's milk counts as dairy. Given this simple definition, it would seem fairly easy to identify foods that are made from cow's milk and foods that aren't. In today's marketplace, it isn't nearly so easy, at least when it comes to processed foods.

Lactose and casein found in many processed foods

The problem is that lactose, one of the primary sugars in cow's milk, and casein, one of the primary proteins in cow's milk, are both added to a wide variety of foods; lactose is added for flavor while casein is often added for emulsification, texture and protein supplementation. Table 1 contains a list of some of the foods where casein can be found. As you will note it is found in a variety of diverse food products. Therefore, the only way to tell for sure whether it is added to a food product is to read the food label.

Table 1

Processed foods that may contain casein
Bakery glazes

Breath mints

Coffee whiteners

Fortified cereals

High-protein beverage powders

Ice cream

Infant formulas

Nutrition bars

Processed meats

Salad dressings

Whipped toppings

Food allergy vs food intolerance

It is important to realize that sensitivity to certain foods may not always be caused by a food allergy, but may be the result of food intolerance. This differentiation is important since these two types of sensitivities occur as a result of two distinct physiological events. While their difference is worth briefly noting here, if you would like further detail please refer to the Food Sensitivity Q+A which gives a great overview of this subject.

Dairy allergy

Food allergies are reactions that involve the immune system. Typically reactions to the casein in dairy products will involve a full-fledged immune response, manifesting as specific as a skin rash, or as general as fatigue. What happens during an allergic reaction is that your immune system cells treat the certain "offending" molecules, casein for example, as if it were foreign and dangerous. Some immune system cells will bind to the offending molecule in the food, triggering a cascade of physiological events that will activate other components of the immune system. This would then harness chemical messengers such as histamine to 'alert' the body that there is 'danger'. Inflammation and the creation of immune complexes that disrupt normal physiological functioning may ensue as a result.

Dairy intolerance

Yet, as noted above, an allergy may not be the only culprit if you have a negative reaction to a certain food such as dairy. Unlike allergies, some adverse reactions to food do not involve the immune system. These types of responses are called food intolerances with lactose intolerance being the most common food intolerance in the United States, affecting as many as 30% of adult Americans. Individuals who have lactose intolerance are sensitive to the milk sugar lactose that is found in dairy products. This intolerance may occur because they do not produce enough of the digestive enzyme lactase, which functions to break down lactose in the small intestines. If the lactose does not get digested it makes its way into the large intestine, causing a host of symptoms, including flatulence and/or diarrhea.

Depending on the speed of a person's digestion, an allergic or intolerance reactions could take place anywhere from 30 minutes to 2 days after eating the dairy product. By that time of course, most people have eaten a variety of other foods which is one of the reasons that it is oftentimes not that simple to identify foods to which we are sensitive.

Hidden culprits: dairy in soy and meat products

There are two special areas in which dairy responses crop up quite often, even though most people would not expect them to; these areas involve soy foods and meats.

Dairy-based reactions to soy foods

As many consumers have chosen to replace some of their beef, chicken, and pork meals with soy-based products, manufacturers of soy-based products often try to place products in the marketplace that match up closely with meat-containing foods (soy hot dogs and sausages are two examples). When they do this protein content is sometimes a problem because unless the soy product is very concentrated in the soy itself, the protein content of the produce is often much lower than its meat-equivalent (this is because the parts of the animals that we eat are mostly muscles, and muscles are made primarily of protein). To boost up the protein content of their soy products, manufacturers often add dairy-based proteins with the most common of these proteins being casein. Casein, caseinates, and sodium caseinate are all words that you might see on a soy food label, and they always indicate the presence of a dairy-based component.

Dairy-based reactions to meat

A second common overlap between processed non-dairy foods and dairy components involves the processing of meat itself. Lactose - one of the key sugars that is found in cow's milk - is often included in processed meats for flavor, and just as occurs with soy products, sodium caseinate is often added as an emulsifier. Frankfurters, Vienna sausages, luncheon meats, chicken sausages and pates all fall victim to such practices. Caseinate is added to ham brine for improved slicing ability.

The research literature on adverse reactions to dairy-containing meats includes a case of near fatal anaphylaxis for a child served chicken soup in a hospital that included sodium caseinate. The bottom line: meat allergy may be dairy allergy in disguise, and meat servings in a single meal can include up to 60 milligrams of casein.

Contaminants in cow's milk

If you haven't already switched to organic dairy products in your meal plan, you'll definitely need to do so in order to determine if you have an adverse reaction to cow's milk. The reason is quite simple: about a dozen pesticide residues are commonly found in non-organic cow's milk. (The source of these pesticides, of course, is the food that the cows were given to eat.) Also commonly found are hormonal residues from hormones that were given to the cows prior to milking, as well as antibiotics. Finally, from cow's milk products like cheese, cream, or butter packaged in plastic containers, residues of the plastic itself are found in the dairy products. These residues are called packaging migrants, and they include the substances DEHP and DEHA (diethylhexyl phthalate and diethylhexyl adipate). Unless you switch over to organic dairy products when trying to determine a dairy reaction, you won't know whether your reaction is occurring due to components of the cow's milk itself, or to these contaminant residues.

Practical tips - how to test for dairy food reactions

For a two-week period, eliminate the following:

After the two-week period, begin to reintroducing dairy-containing foods into your meal plan. Start with organic low-fat cow's milk, organic skim cow's milk, or organic nonfat cow's milk, and just try about 4 ounces total at two different times during the day.

On the following two days, go back to your dairy-free meal plan, and wait and see if you experience any of the reactions you noticed before you removed dairy (the two day rule). If not, introduce another dairy-containing food that you would like to keep in your meal plan, for example, organic cow's milk yogurt. Stick with the highest quality and least complicated product when you conduct your test - for example, try 4 ounces of a plain, nonfat organic yogurt rather than a flavored product or a product containing fruit on the bottom. Follow the the two-day rule again. If you still experience no problematic reaction, you may want to go on and experiment with a non-dairy food that contains dairy protein, like a soymilk cheese that contains casein.

The process is time-consuming, and it takes a lot of patience! But it is still the best way to decide if dairy is a problem for you or not.