What If I've Tested Negative for Lactose Malabsorption?

If you've tested negative for lactose intolerance, how does that fit into the FODMAPS picture?

First of all, let's review the test for lactose intolerance. The patient consumes a known amount of lactose. If the lactose is poorly digested and absorbed in the small intestine, it continues "down the line" to the large intestine, where it is fermented by the resident bacteria. They produce hydrogen gas as they ferment the lactose. Some of this gas is absorbed into the patients blood stream, where it travels to the lungs and is exhaled. If there is a sharp rise in the amount of hydrogen exhaled after the patient consumes the lactose, that is considered "positive" for lactose malabsorption. One thing to keep in mind is the fact that approximately 20% of us are not colonized by hydrogen-producing bacteria; instead, our resident bacteria many produce other types of gas such as methane or hydrogen sulfide (bad breath, anyone?).  Lactose-malabsorbing individuals in this category will falsely test negative for lactose intolerance on a hydrogen breath test alone, but might be positive if tested for both hydrogen and methane exhalation. The results of the lactose test really need to be viewed together with the patient's history of symptoms after consuming lactose, both during the test and at other times.

If someone has tested negative for lactose malabsorption AND doesn't particularly have a history of symptoms after ingesting milk products, it is pretty safe to say that individual is not lactose-intolerant.

However, even adults who tolerate lactose well in general do have limits to how much lactose they can handle. Because the effects of FODMAPS carbohydrates are additive, excessive lactose intake could put you over the top, and contribute to symptoms mostly caused by the other FODMAPS.

How much lactose is "excessive"? The answer to that question varies from one person to the next, but to put things in perspective, check out these generalizations about the lactose content of milk products:

Fluid milk: 11-14 grams per cup

Lactose-free milk: 0 grams per cup

Evaporated milk: 24 grams per cup

Yogurt: 5 grams per cup

Ice cream: 12 grams per cup

Butter: trace per 1 tsp

Most cheeses: 0-2 grams per ounce

Whey protein concentrate: varies

Whey protein isolate: trace per serving

To learn more about lactose intolerance and the FODMAPS elimination diet, visit www.ibsfree.net

Comments

[Nutrition to kitchen]

Wow, I had no idea evaporated milk had so much lactose in it. Thanks for the info!

[Julie]

Really interesting! You know I learn something new every time I come to your site. Well done!