Nothing can get ahead of lactose load

Dear Dr. Roach: I am a 79-year-old woman in excellent health. Over the past year or two, I experience gas, loose bowel movements and occasionally explosive diarrhea. A colonoscopy and blood tests revealed no cause. A few months ago, I decided to monitor all dairy in my diet, and the symptoms have improved with the help of taking lactase tablets when I eat any dairy. I diligently read lists of ingredients and I’m surprised by all the foods which contain milk, such as bread. If I forget to take lactase, the symptoms reappear about 2 1/2 hours after eating the culprit food. Is there anything else I can take later at the onset of the symptoms to ward off the digestive distress? And is there any way to regain the missing intestinal enzyme that causes the problems to begin with?

J.A.T.

Answer: Lactose intolerance is caused by an inability to make the enzyme lactase, which breaks down lactose (a sugar found in milk). Without this enzyme, the sugar cannot be metabolized, and is digested by intestinal bacteria, creating hydrogen gas and shortchain fatty acids, which in turn cause symptoms. The “digestive distress” you delicately mention can include abdominal pain, gas, bloating and diarrhea.

Lactose intolerance is common, and people are more likely to develop it as they get older. The amount of lactose needed to cause symptoms varies greatly between one person and another, depending on the amount of lactase enzyme they make. Those with very little have the worst symptoms.

Treatment is to reduce lactose intake, and reading labels is certainly your best bet. People with milder disease can do fine just by eliminating milk and ice cream, which have the highest amount of lactose. The lactase enzyme replacement tablets, such as Lactaid, are effective for many and allow them to consume dairy products.

Once the lactose is in your system, you are out of luck if you haven’t taken the lactase enzyme. There’s no way to get the enzyme in ahead of the lactose load to your intestines. Sadly, gene therapy to replace the enzyme is not a reality.