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Lactose Intolerance

What is lactose intolerance?
Lactose intolerance is the inability to digest lactose, the sugar found in milk. The majority of people who are not of Northern European ancestry or who do not customarily include dairy products in their diets are affected. In the United States, up to 75 percent of all adult African Americans and Native Americans, and 90 percent of Asian Americans, are prone to develop lactose intolerance.

What are the symptoms?
Consuming lactose causes bloating, abdominal pain and, often, diarrhea. Symptoms usually develop between 30 minutes to two hours after ingesting milk products and can be mild or severe depending in part on how much lactose is consumed and the severity of the intolerance. However, many people who are lactose intolerant can comfortably consume cultured dairy products, including yogurt, buttermilk and cheese, in which the lactose has been broken down by bacterial action.

What are the causes?
The cause stems from a deficiency of lactase, an enzyme produced in the lining of the small intestine. Lactase is needed to help digest milk sugar. Without it, lactose in incompletely broken down. When lactose is not digested, water is retained in the bowel. This results in bloating and watery diarrhea. Lactose that passes into the large intestine is then fermented by bacteria. This produces carbon dioxide, hydrogen, and methane. Bloating, cramping, and flatulence, or passing gas results. Although rare, babies can be born with lactose intolerance (it occurs most often among premature infants because lactase increases in the fetus late in development) or you may become intolerant as you get older if your diet does not contain much milk. Lactose intolerance can also occur as a result of intestinal disorders, such as celiac disease, gastroenteritis or an inflammatory bowel disease such as Crohn’s disease. Sometimes, a disease-related intolerance is temporary, but if it is caused by a long-term illness, it is likely to become permanent.

What is the conventional treatment?
No current medical treatment can correct the underlying enzyme deficiency, so the only way to prevent symptoms is to avoid milk, or consume it only in small quantities. However, lactose enzyme tablets are available and can help break down any milk sugar you do consume. The pills are typically taken before eating foods that contain milk or milk products. This strategy doesn’t work well for everyone but often can be very helpful. You also can buy lactose-free milk or milk that contains reduced amounts of lactose. Because milk sugars are found as ingredients in many foods, be sure to check the labels of prepared foods for lactose, which is sometimes added to cereals, instant soups, salad dressings, chocolate and baking mixes. In addition to "lactose," words to look for include whey, milk byproducts, fat-free dry milk powder, malted milk, buttermilk and dry milk solids, all of which may contain lactose. If you have a severe intolerance, make sure that any medications you take, prescription or over-the-counter, do not contain lactose.

What therapies does Dr. Weil recommend for lactose intolerance?
Dr. Weil emphasizes that lactose intolerance is not a disease, just a variation in the genetic makeup of human beings. Milk is not necessary for the health of human beings once they are weaned as infants. Indeed, the inhabitants of Asian countries including Japan – in which animal milk is seldom consumed – tend to perform better than Americans on virtually every measure of health, including longevity and freedom from cardiovascular disease.

If you are lactose intolerant, avoid milk and milk products, other than cultured foods such as yogurt, buttermilk and cheese. If you miss the taste of dairy products, look into lactose-free, vegetarian alternatives such as milk and cheese made from soy, rice or almonds. Once available only in health food stores, these are now carried by virtually all grocery stores.

To ensure that you get sufficient calcium for bone strength explore such non-dairy sources as dark green, leafy vegetables (these may, in fact, be better ways to get calcium, as they also contain abundant vitamins and minerals, significant amounts of fiber, and no fat) and calcium-fortified foods and beverages.

Women who need to supplement their dietary sources of calcium should take 500 to 700 mg of calcium citrate in two divided doses with meals, for a total daily intake of 1,000-1,200 mg from all sources. Men need 500 mg from all sources, and probably do not need to supplement (higher amounts of calcium in men have been linked to increased risks of prostate cancer). And because most people don’t get enough vitamin D, which is needed for calcium absorption, both men and women should take a daily supplement of 2,000 IU of vitamin D3.