Lactose Intolerance Diet

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Lactose Intolerance Diet

Research and general acceptance

Resources

Definition

Lactose intolerance is a condition caused by the inability to digest lactose, a sugar found in milk. The lactose intolerance diet is a diet designed to treat the symptoms that result from undigested lactose.

Origins

No single person originated the lactose intolerance diet. Physicians treating symptoms of lactose intolerance have developed this diet through observation and trial and error by their patients.

Description

Lactose is the main sugar in milk. Normally when lactose reaches the small intestine, it is broken down into simpler sugars by the enzyme lactase. These simpler sugars are absorbed into the bloodstream and eventually are used as fuel for he body.

Lactase is made in the cells that line the small intestine. In some people, these cells do not make enough

Calcium and lactose in common foods

Foods	Calcium content (mg)	Lactose content(g)
Soymilk, fortified, 1 cup	200-300	0
Sardines, with edible bones, 3 oz	270	0
Salmon, canned, with edible bones, 3 oz	205	0
Broccoli, raw, 1 cup	90	0
Orange, 1 medium	50	0
Pinto beans, ½ cup	40	0
Tuna, canned, 3 oz	10	0
Lettuce greens, ½ cup	10	0
Dairy products
Yogurt, plain, low-fat, 1 cup	415	5
Milk, reduced fat, 1 cup	295	11
Swiss cheese, 1 oz	270	1
Ice cream, ½ cup	85	6
Cottage cheese, ½ cup	75	2-3

source: National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, U.S. Department of Health and Human Services.

(Illustration by GGS Information Services/Thomson Gale.)

lactase. In a few people, they do not make any at all. When people do not make enough lactase, they cannot digest some portion of the lactose they have eaten. Lactose that is not broken down cannot be absorbed into the blood. Instead, it remains in the large intestine (colon) where bacteria convert it into lactic acid. Lactic acid is a laxative and an irritant to the colon.

Symptoms of lactose intolerance include nausea, bloating, abdominal pain or cramps, abundant gas, and diarrhea. These symptoms usually begin anywhere from 30 minutes to 2 hours after eating a food that contains lactose. Symptoms of lactose intolerance can be uncomfortable enough to temporarily interfere with daily activities, however, they do not harm the digestive system and lactose intolerance does not progress to any other disease or disorder.

Lactose intolerance is an extremely common condition. It rarely develops before age six, and is due to a genetically programmed decline in lactase. This decline begins around age two, the age when most infants have finished the transition from breast milk to solid food. In some people this decline continues to the point where in late childhood or early adulthood they develop lactose intolerance symptoms. Lactose intolerance is strongly linked to race and ethnicity. People of Northern European ancestry have the lowest rate of lactose intolerance, about 5% In Hispanic, Jewish, and Southern European populations, the rate is about 70%, and it reaches 90% or more in Asian and African populations. Worldwide, in adults the inability to digest lactose is much more common

KEY TERMS

Enzyme —a protein that change the rate of a chemical reaction within the body without themselves being used up in the reaction

than the ability to digest it. Although the symptoms are similar, lactose intolerance is not the same as cow’s milk intolerance. Cow’s milk intolerance is a food allergy and causes an allergic reaction. Only about 3.4% of Americans have cow’s milk intolerance.

The degree to which people are lactose intolerant varies widely. Some people can drink a glass of milk daily without developing unpleasant symptoms. Others can drink only small amounts of milk at a time, and have fewer symptoms if milk is mixed with food. Some people can eat cheese, ice cream, or yogurt, but cannot drink milk. A few people are 100% lactose intolerant and even the smallest amount of lactose will produce unpleasant symptoms.

Although the greatest quantities of lactose are found in milk and dairy products, milk is used in the preparation of many processed foods such as chocolate bars, puddings, and soups. Food labels must list all the ingredients in processed foods. Lactose intolerant individuals should look for these words on the label that indicate the presence of lactose: milk, condensed milk, whey, curds, milk-by-products, dry milk solids.

Lactose is found in other unlikely places such as:

bread and baked goods and biscuit, pancake, and cookie mixes
processed breakfast cereals and breakfast drinks
instant mashed potatoes
lunch meats (except kosher meats which are lactose-free)
salad dressings
all chocolate candies, caramels, butterscotch, and many others
as filler in medications. As many as 6% of prescription and over-the-counter drugs contain lactose

The amount of lactose found in these hidden sources is not enough to affect most people, but for the severely lactose intolerant, it can be enough to cause symptoms and make meal planning a necessity and eating out difficult.

Many individuals diagnose themselves as lactose intolerant using an elimination diet. However people who think they may be lactose intolerant should see their physician because the symptoms of lactose intolerance can be quite similar to those of more serious and sometimes progressive diseases such as celiac disease (a gluten intolerance), Crohn’s disease, giardia (a parasitic infection of the bowel), and inflammatory bowel disease Lactose intolerance can be diagnosed by giving the individual lactose and then measuring changes in the sugar (glucose) level in their blood. In lactose intolerant individuals lactose is not broken down into sugars that can be absorbed from the intestine. Therefore, the level of glucose in the blood will be lower than expected. Lactose can also be diagnosed by a hydrogen breath test.

Lactose and diet

Lactose intolerance is treated by eliminating lactose from the diet beyond the level where it produces symptoms. Alternately, enzymes such as LACTAID or Dairy Ease can be added to milk 24 hours before drinking. These enzymes pre-digest lactose and can eliminate 70-99% of it. Lactose-reduced milk is available at many supermarkets. All LACTAID and Dairy Ease milk is 70% lactose-free except for non-fat LACTAID, which contains no lactose. When eating other foods that contain lactose, LACTAID and Dairy Ease capsules are taken at the same time that an individual begins eating. These capsules contain enzymes to help digest lactose.

Since dairy products are the main source of calcium in the standard American diet, people who eliminate milk, cheese, yogurt, and other dairy products must adjust their diet to get enough calcium. Calcium is critical to building and maintaining strong bones and teeth and is needed for metabolic processes such as muscle contraction and nerve impulse transmission.

The United States Institute of Medicine (IOM) of the National Academy of Sciences has developed values for the adequate intake (AI) of calcium. These values are based on age and gender. Some nutritionists and researchers believe that they are too low. The AI values for calcium are listed below.

children birth-6 months: AI 210 mg
children 7-12 months: AI 270 mg
children 1-3 years: AI 500 mg
children 4-8 years: AI 800 mg
children 9-13 years: IA 1,300 mg
adolescents 14-18 years: IA 1,300 mg
adults age 19-50:IA 1,000 mg
adults over age 50: IA 1,200 mg
pregnant women 18 years and younger: IA 1,300 mg
pregnant women over age 18:IA 1,000 mg
breastfeeding women 18 years and younger: IA 1,300 mg
breastfeeding women over age 18: IA 1,000 mg

Some good sources of calcium that do not contain lactose are:

sardines with bones, canned in oil, 3 ounces: 270-325 mg
salmon with bones, canned, 3 ounces: 180-205 mg
tofu, firm, made with calcium sulfate added, 1/2 cup: 204 mg
pinto or red beans, cooked, 1/2 cup: 43 mg
white beans, cooked, 1/2 cup: 113 mg
bok choy, 1/2 cup cooked: 61 mg
bread, whole wheat, 1 slice: 20 mg
orange juice, fortified with calcium, 6 ounces: 200-260 mg
soymilk, 1 cup: 200-300 mg

A dietitian can help the severely lactose intolerant person develop a meal plan that will meet their dietary need for calcium and/or recommend a calcium supplement. Calcium supplements are available over-the-counter at pharmacies and supermarkets.

Function

Lactose intolerance cannot be cured. The purpose of the lactose intolerance diet is to bring the symptoms of bloating, gas, abdominal discomfort, and diarrhea under control so that the individual is comfortable, and the symptoms do not disrupt his or her daily activities.

Benefits

The benefit of a lactose intolerant diet is that the uncomfortable symptoms of bloating, nausea, stomach cramps, and diarrhea are controlled.

Precautions

Lactose intolerance is variable. Individuals must work out through trial and error how much and which lactose-containing foods then can eat without stimulating symptoms. During trial and error experimentation, there will be moments of misjudgment when symptoms develop.

Risks

The greatest risk to this diet is that the individual will not get enough calcium.

QUESTIONS TO ASK THE DOCTOR

Why do you think my symptoms are caused by lactose intolerance and not another gastrointestinal disorder
Do you recommend using lactose-reduced milk or enzyme pre-treatment of milk, or is it better to simply eliminate milk from my diet?
Should I take a calcium supplement? If so, how much and how often?
Can my children inherit this condition?

Research and general acceptance

The lactose intolerant diet is accepted by medical professionals as a standard treatment for this condition. The diet has existed for many years and is not controversial.

Resources

BOOKS

Field, Tamara. The Milk Soy Protein Intolerance (MSPI) Guidebook/Cookbook New York: Vantage Press, 2001. .

Joneja , Janice V. Dealing With Food Allergies: A Practical Guide to Detecting Culprit Foods and Eating a Healthy, Enjoyable Diet Boulder, CO: Bull Pub., 2003. .

Rockwell, Sally. Calcium Rich & Dairy Free: How to Get Calcium Without the Cow Pomeroy, WA: Health Research Books, 2005. .

Schroeder, Florence E. Cooking Without Milk: Milk-Free and Lactose-Free Recipes. Nashville, TN: Cumberland House Pub., 2002.

ORGANIZATIONS

American Gastroenterological Association. 4930 Del Ray Avenue, Bethesda, MD 20814, Telephone: (301) 654-2089. Website: <http://www.gastro.org>

International Foundation for Functional Gastrointestinal Disorders. P. O. Box 170864, Milwaukee, WI 53217, Telephone: (888) 964-2001. Fax: (414) 964-7176. Website: <http://www.iffgd.org>

National Digestive Diseases Information Clearinghouse (NDDIC). 2 Information Way Bethesda, MD 20892-3570. Telephone: (800) 891-5389. Fax: (703) 738-4929. Website: <http://digestive.niddk.nih.gov>