Answers to Questions from Readers, part 6

Q. I have taken lactase several times now and gotten an upset stomach, cramping and bowel pain. I guess my question is: Is it possible to have too much of the enzyme in your system?

Q. Are the Ultra Lactaid pills constipating? Lactaid, by the way, denies any knowledge of this side effect. I called them a couple of years ago and asked.


Q. I now strongly suspect that some brands of pills can themselves cause diarrhea, especially in large doses. Do you have any information on this?

I've been getting an increasing number of complaints that lactase pills are causing problems. As you can see, though, each person seems to have a different complaint.

Giving advice on this issue is difficult, because except for some anecdotal complaints such as these, there is nothing in the medical literature about adverse reactions to lactase pills. Nothing. They are some of the most benign pills known to the pharmacopeia.

So what's going on?

One or two actual medical problems are known. There is one single case of a person being allergic, not to the lactase, but to the yeast that is used to manufacture the lactase. And a few brands of pills may contain mannitol, an artificial sugar substitute, as an ingredient. Susceptible people are known to get diarrhea from mannitol.

Other than that, the problem is compounded because people are taking the lactase with meals. So any reaction may come from the meal rather than from the pill. And to make things more complicated, when people try to relieve symptoms or cure a supposed food-based problem, they often make many changes to their regular diet simultaneously. The reaction could come from any or all of these, alone or in combination.

You might want to consider the possibility that if your system has been producing mild diarrhea for a long time from small quantities of lactose, you've come to think of this state as being "normal." Getting sufficient lactase into your system to eliminate the symptoms would feel much like constipation by comparison. Remember that doctors define a normal amount of bowel movements as anywhere from three times a day to three times a week.

Or you may be having a psychological reaction to knowing you're about to eat food that contains something you shouldn't have. (Don't scoff. Many studies have shown a strong psychological reaction to milk even in people who do not test out as being LI.)

It may even be something as simple as having a stomach flu and not realizing it.

Not very helpful, I admit. All I can say is that you should try several different brands of lactase. Some people simply react better to some brands than to others.

You might also look at my Lactase page in my LI Basics section. I gave lots of helpful hints as well as answers to what and when and how and how much lactase. You may find something useful there.

Q. I have read references to a lactose-tolerance test. What is that?

There are two basic types of lactose-tolerance test. Both start with a person drinking either a solution of lactose and water or a glass of milk.

The most common test is called the breath hydrogen test. If you do not digest lactose then the bacteria in your colon will ferment it, producing hydrogen gas. This gas is measured in your breath. Measurements are made at intervals for several hours to see what the peak is. If the peak is higher than a certain amount, you are said to be lactose intolerant.

Because the breath hydrogen test needs special equipment to measure the hydrogen, some places still use the older blood glucose test. The idea behind this one is that if you do digest lactose, your blood sugar will go up. Therefore blood samples are taken at intervals to measure the glucose level. If it goes up, then you are not lactose intolerant. This makes it an indirect test and so not as sensitive, besides which you get stuck by a lot of needles, both of which have caused it to go out of favor.

For more info, see my LI Tests page.

Q. How should a doctor diagnose lactose intolerance?

The symptoms of LI are diarrhea, gas, cramps, flatulence, and borborygmi (the rumbling of air through the intestines) after the ingestion of milk products. Any one of a number of tests can be given to a patient to confirm LI. The major tests are the breath hydrogen test (since the bacteria in our colons produce hydrogen gas when they ferment undigested lactose) or the blood glucose test (an indirect test measuring the lack of an increase in blood glucose from the failure to digest lactose). The patient drinks a lactose solution and then either a breath sample or a blood sample is taken at intervals thereafter.

The problem for a doctor is to determine when LI is the problem and when the symptoms may be coming from any number of other, more serious, diseases and disorders with similar symptoms that the patient may have instead of or in addition to LI. You'll have to ask a real doctor how that determination is made.