What is Lactose Intolerance?
Lactose Intolerance, also now being called Lactose Maldigestion, is a condition that affects many millions of people in the US. It's basically the inability of the digestive system to properly digest milk products that contain lactose (also known as milk sugar). For more information on which milk products contain lactose, go to the Hidden Lactose page.
The body can only directly utilize the simple sugar glucose. Dextrose, or corn sugar, is glucose in dried form. Lactose is a complex sugar that is found in milk (all milk, not just cow's milk). When you are born, your body normally produces an enzyme called lactase that breaks the lactose sugar molecule down into glucose so the body can digest it. In the grand scheme of things, you are only meant to survive on your mother's milk for a relatively short time, so lactase is a very necessary enzyme for a child to have. But at some point you are weaned from mother's milk. If we didn't harvest the milk from other animals, the body would have no need for lactase once you were off the breast.
The body is genetically programmed to stop producing lactase at an early age. Most people still make some lactase though, usually enough to digest the milk and dairy products they ingest. Whether this ability to continue to produce lactase is the result of the continued intake of dairy products (fooling the body into the fact that we're still nursing), natural selection, or both, I don't know.
Some people stop producing lactase altogether, or at least don't produce enough to handle a normal intake of dairy products. These people cannot digest lactose, and are therefore lactose intolerant. All adults have lost some of the ability to produce lactase, but the amount they produce may still be sufficient. Some may produce borderline amounts, and the amount they may produce is related to stress and other factors. So if you are one of the borderline producers, you may have no problems with an ice cream cone on the weekend when you are relaxed, but have a problem with a slice or two of pizza at lunch at the office when you are stressed.
So what if I don't produce lactase? Why is that a problem?
Here's the issue: Lactase is usually produced in the intestines. It breaks the lactose down into glucose so the body can absorb it. When the lactose is not broken down into glucose, several things happen. The lactose itself interferes with the normal absorption of water from the food in the intestine - in fact it reverses the process putting more water into the intestines. This results in diarrhea and the onset can be very quick because the excess water also travels faster through the intestines. The bacteria that live in the intestines can digest lactose, but they're not supposed to ever see it. What happens when they do? They digest it but in the process they produce a lot of carbon dioxide and methane gas and other by-products. The result is you bloat up and usually have diarrhea.
What are the symptoms of Lactose Intolerance?
The primary symptom is an excess of intestinal gas. This can be minor and not always associated with the dairy products you ate. After all, a lot of food causes gas. When you get major amounts of gas, the result can be very painful. If the gas is trapped, you will bloat up to the point where sometimes it is difficult to breath due to the excess pressure on the diaphragm. Cramping is sure to occur. A major case of "the trots" is sure to follow. You will be in distress until the gas and loose stools pass. It can be several hours of agony.
How can I tell if I have Lactose Intolerance?
Your doctor can now perform a simple breath test to determine if you have Lactose Intolerance. You can also cut out all products from you diet that contain lactose and see if the symptoms abate. This is harder than you think, but that's the primary purpose of this website. See all the various sections on how to determine which food products contain lactose.