Lactose Intolerance is a Global Problem

More adults are lactose intolerant than lactase persistent

/ Author:  / Reviewed by: Robert Carlson, M.D

Adding milk to your coffee may seem normal, but it's not. Most adults globally cannot tolerate milk and its main sugar, lactose.

Drinking milk as an adult may seem like a common practice but or most of the world, it is not. The reason is due to most adults stop producing the enzyme lactase which breaks down lactose.

Milk can be quite beneficial and is a source of Vitamin D and calcium. A milk allergy or lactose intolerance can lead to some serious health consequences but there are ways to get past this common problem.

Lactose Intolerance is More Common than Uncommon

According to a 2009 study from the University College London, the ability for adults to break down lactose follows the history of dairy production in Europe. The domestication of cows which led to the cultivation of milk occurred approximately 7,500 years ago. Through natural selection, lactase persistence became common among Europeans.

Lactase persistence is the ability to produce the enzyme lactase throughout one's life. Most individuals stop producing lactase after a child is weaned off of their mother's milk. Because of this, most adults around the world are lactose intolerant.

According to the National Institute of Child Health and Human Development (NICHD), between 30 to 50 million Americans are lactose intolerant. That may seem like a large number, but it is actually quite small compared to stats across the globe.

Lactose intolerance affects approximately 95 percent of Asians, 50 to 80 percent of Hispanics, nearly 100 percent of Native Americans and 60 to 80 percent of African Americans. Lactose intolerance only affects approximately two percent of individuals of Northern European descent.

That means that the ability to break down lactose is not normal rather than the inability to break down lactose. Next time you are drinking milk, think about how strange that is compared to the rest of the world.

Dealing with Lactose Intolerance

Lactose intolerance can lead to stomach pain, gas, cramps, diarrhea or vomiting. The symptoms are not life threatening but can quite problematic which will lead to people avoiding dairy products.

Avoiding dairy products means losing a valuable source of riboflavin, phosphorus, calcium and vitamins A and D. Calcium deficiency can lead to an increased risk of bone fractures in older individuals and osteoporosis.

Vitamin D aides in the absorption of calcium. There have been many studies linking vitamin D to a variety of diseases.

Recent studies have shown vitamin D to possibly slow down prostate cancer, improve hay fever symptoms and reducing menstrual cramps.

Low levels of vitamin D were also associated with depression. Vitamin D deficiency in children causes rickets.

Aside from dairy products, vitamin D can be had for free. Spending time outdoors in the sun will provide you with vitamin D. Be careful about overexposure and wear sunscreen if you are out in the sun for extended periods of time. Just 10 to 15 minutes three times a week will produce enough vitamin D.

The easiest thing to do to avoid lactose intolerance is to take any one of the many over-the-counter pills that contain lactase. This can ease symptoms while eating dairy products.

Other ways to minimize lactose intolerance symptoms include drinking low-fat or fat free milk or combining milk consumption with other food. Low-fat or fat free hard cheeses, cottage cheese, ice cream or yogurt have lower lactose levels than milk which will help reduce symptoms.

Difference Between an Allergy and Intolerance

While many individuals have lactose intolerance, that is not the same as a milk allergy.

A milk allergy is a response to a protein and not lactose, which is a sugar. The protein in question is casein and the body reacts much the same way it would to other allergens such as dust mites, grass pollen or tree pollen. Milk allergy may trigger hives, stomach pain, vomiting, wheezing, itchy eyes and anaphylaxis.

Approximately two to five percent of all infants have a milk allergy. Luckily, most grow out of this by the age of three however some children may have a lifelong allergic reaction to milk.

For children with a milk allergy, there are ways to treat the allergy and reduce the symptoms. One approach is through immunotherapy which exposes the allergy sufferer to a small dose of the allergen, gradually increasing the dose over time. This causes the immune system to alter its response to the allergen and reducing symptoms. 

A small study conducted by the Johns Hopkins Children’s Center showed the benefits of dry milk powder to reduce allergy symptoms. The study involved 30 children, 10 children received liquid drops of milk extract under the tongue, 10 children received one gram of milk protein a day and 10 children received two grams of milk protein a day.

Over the course of two years, 14 out of the 20 children who took milk protein as a dry powder passed a food challenge test which exposed the child to eight ounces of milk. While the dry milk powder was effective, there were side effects associated with the treatment including difficulty breathing and abdominal pain.

For most Europeans and Americans, lactose intolerance is more a nuisance than a crippling disease. While many people have severe reactions to dairy products, medication to eliminate those symptoms are available in any pharmacy. 

Review Date: 
April 23, 2012