Lactose Intolerance

I have been reacting to all dairy except for mozzarella and yogurt for as long as I remember. Raised on organic Edensoy soymilk and frozen yogurt, I never felt the urge to consume dairy with high amounts of lactose, aside from cheese (hm, cheese) or the occasional ice cream treat. Lactose intolerance seems to have become more popular now than when I was growing up, so I would like to go over why some of us can tolerate dairy, whereas it can be quite the uncomfortable experience for others.

What is lactose intolerance?

Our ability to digest the carbohydrates of milk varies widely from person to person, with prevalence differing according to ethnicity. Lactase is the enzyme required to digest lactose, a milk sugar. When lactose comes into contact with its enzyme lactase, lactose is split into absorbable components: glucose and galactose. As we get older our ability to produce the enzyme lactase decreases in about 75 percent of people, resulting in high rates of lactose intolerance within the general population.

Without lactase (aka the enzyme required to absorb dairy) unabsorbed lactose in the gut draws water into the intestines, resulting in diarrhea, while intestinal bacteria use some of the lactose for their own energy producing gas and intestinal irritants. Other common symptoms of lactose intolerance after the consumption of dairy include nausea, pain, and excessive gas.

Degrees of intolerance to dairy varies widely between individuals. Some can tolerate a glass or two a day of milk until they get symptomatic, whereas others can feel the effects of undigested lactose after a little piece of cheese. In rare cases people are unable to tolerate any amount of dairy. Milk sensitivity can also be due to an allergic reaction to the dairy protein and, unlike the lactose intolerant, these individuals are typically unable to tolerate cheese or yogurt. This is a response of the immune system and is not the same thing as lactose intolerance.

Why can some people eat certain cheeses or yogurt?

 For some people intolerant to dairy, the consumption of yogurt, aged cheese, or mozzarella may produce minimal or no discomfort.  The production of these products involve the fermentation of milk, and percentage of lactose content in dairy product is significantly lower in fermented foods. The bacteria or molds used to ferment the dairy into yogurt digests lactose in the process. The bacteria in some yogurts may also find residence in the intestinal tract during digestion, thus further reducing the uncomfortable consequences of lactose intolerance. It is important to note that some yogurts do contain added milk solids and therefore also contain additional lactose, so make sure to read the labels on your yogurt.

How will I know if I’m lactose intolerant?

For some, the inability to digest the milk sugar lactose is obvious, due to the digestive consequences in their digest. For others, it is not quite so obvious, as the symptoms are minimal and they may have developed a tolerance to the milk. The most common lab test available for lactose intolerance is called the hydrogen breath test, the measurement of hydrogen in your breath after ingesting a certain amount of lactose. However, if you have any of the symptoms mentioned above (especially bloating), it may be worth it to eliminate dairy from the diet for a bit to see what happens. If you feel better there’s a good chance you’re lactose intolerant, but be aware that there are other reasons why dairy causes uncomfortable symptoms in someone, including sensitivity to proteins in diary like casein or whey.

Hope this provides some answers and clarity regarding the lactose intolerant. Remember there are other sources of dietary calcium, and you may be absorbing very little of the calcium from dairy if you are unable to properly digest milk products.

PLEASE NOTE: ALL MATERIAL AND INFORMATION CONTAINED ON THIS WEBSITE IS FOR EDUCATIONAL PURPOSES ONLY AND DOES NOT MEAN TO REPLACE OR AUGMENT ANY ADVICE OR CONSULTATION PROVIDED BY A LICENSED HEALTH CARE PRACTITIONER OR PHYSICIAN.

SOURCES

Alm, L (1982). Effect of fermentation on lactose, glucose, and galactose content in milk and suitability of fermented milk products for lactose intolerant individuals. Journal of Dairy Science, 65(3): 346-52.

Sizer, F., Whitney, El., Piche, L. (2009). Nutrition: Concepts and Controversies (1st Canadian ed). Toronto, Ontario: Nelson Education Ltd.