As a registered dietitian in Canada, I have concern about people questions regarding milk products for those who are lactose intolerant.

I have just been to your website. As a registered dietitian in Canada, I was interested in your Q & A site. I have a concern about people’s questions regarding milk products for those who are lactose intolerant or allergic to milk.

Those who are allergic to milk, are usually allergic to the protein, often casein, in milk. These individuals (between 2 – 8% of infants/children) should not have any cow or goat milk products. They must avoid all milk products.

In actual fact, it is the lactose intolerant individuals (unable to digest the lactose or sugar in milk) vary in the ability to digest various milk products. Foods such as aged cheese (cheddar) and yogurt (with live bacteria culture) may be reasonably well tolerated. Some may also tolerate small amounts of milk as long as they are eaten with a meal. Lactaid and lactase milk have the lactose already digested (99%) and are often well tolerated. Allergic patients should not drink Lactaid or lactase milk. Interestingly enough there is some good recent research that shows that individuals who have been lactose intolerant can actually improve this condition through continuing to drink small amounts of dairy products every day. Drops and pills can also assist in digesting lactose and hence allow individuals to continue to enjoy dairy products.

To summarize: Most individuals who are allergic to milk are allergic to the protein and therefore must avoid all milk. The symptoms may be anaphylaxis (note: difficulty breathing or swallowing), rashes and/or diarrhea. This should be diagnosed by a doctor.

Lactose intolerance can be diagnosed with a hydrogen breath test. The symptoms are usually diarrhea, bloating, gas and cramps. Patients can usually continue to drink or eat small amounts of dairy products, or use the lactose-reduced products.

Hope this helps your readers.

Thanks for your comments. I think the confusion may be over people’s use of the term milk allergy. Sometimes it’s a lactase deficiency and sometimes an allergic reaction to milk protein. The public, unfortunately, sees no difference, only feels symptoms and assume they are allergic to milk so they don’t drink it.

Infants and children are more often allergic to the protein and adults more often develop a lactase deficiency. People with lactose intolerance may tolerate small amounts of milk, but dietitians never recommended milk to persons with an allergy to milk protein. I also recommend using Lactaid reduced milk for the lactase deficient individual, but not for persons with a milk protein allergy.

I have read of the research that lactase deficient persons should continue to use dairy products as their tolerance of lactose may improve. I also encourage individuals who don’t drink milk because it causes symptoms to see their doctor for a diagnosis. Thanks for writing.