LACTOSE-CONTROLLED DIET

Description
The Lactose-Controlled Diet limits intake of milk and milk products to the amount tolerated by the individual.  Refer to Lactose Maldigestion medical nutrition therapy protocol for medical nutrition intervention strategies (1).

Indications
The Lactose-Controlled Diet is indicated in patients who are lactose intolerant; they are deficient in the enzyme lactase and are unable to tolerate ingested lactose.  Lactose maldigestion occurs when digestion of lactose is reduced as a result of low activity of the enzyme lactase, as determined by the breath hydrogen test (2). Interpretation of the terms used to describe lactose maldigestion varies.  For example, lactose intolerance refers to the gastrointestinal symptoms resulting from consumption of too much lactose relative to the body’s ability to break it down by the intestinal enzyme lactase (1). Lactose maldigestion or its symptoms (lactose intolerance) should not be confused with a milk allergy, which is an allergy to milk proteins, not lactose.  Lactose maldigestion is present in 70% of the world’s adults and 20% to 25% of the US population.  It is most prevalent among African-Americans, Asians, Hispanics, Native Americans, and people of Jewish descent.  Lactose not hydrolyzed by lactase in the small intestine passes into the large intestine, where it is broken down by bacteria.  The products of bacterial degradation can irritate the mucosa and raise the osmolality of the intestinal contents, causing a net secretion of fluid.  Symptoms include bloating, abdominal pain, flatulence, and diarrhea, usually within 30 minutes after ingestion of lactose-containing foods.

    Lactose maldigestion is not a disease, but a normal physiologic pattern (3).  Primary lactase deficiency is the most common type and occurs as a normal physiological process in which lactase production in the brush border of the small intestine is reduced (3).  Lactase deficiency may be secondary (secondary lactase deficiency) to significant protein-energy malnutrition, acquired immunodeficiency syndrome (AIDS), or iron deficiency anemia.  Secondary lactase deficiency has also been observed following the use of antibiotics and anti-inflammatory drugs for arthritis.  A transient secondary lactase deficiency may occur following viral gastroenteritis.  It has been observed following surgical resection of the stomach or small bowel when there is a decrease in the absorptive area, following radiation therapy to the gastric or pelvic area, and after prolonged disuse of the gastrointestinal tract (eg, with total parenteral nutrition).  However, the lactase activity may return to normal in the latter conditions over time.  In children, it is typically secondary to infections or other conditions, such as diarrhea, AIDS, or giardiasis.  Lactose intolerance may also be secondary to conditions that produce intestinal damage, such as celiac sprue, regional enteritis, Crohn’s disease, and gluten-sensitive enteropathy.

    Treatment is aimed at the underlying disorder in order to restore the patient’s tolerance to lactose and to eliminate lactose restrictions.  Evidence suggests that people with medically confirmed lactase maldigestion can include the recommended number of servings of milk and other dairy foods in their diet, which may actually improve their tolerance to lactose (1-3).

    In feeding malnourished hospitalized patients and other patients with lactose intolerance, intolerance to 12 g of lactose can be clinically relevant.  The following are used to determine the presence of lactose intolerance:

• A diet history can reveal symptoms of lactose intolerance following ingestion of lactose.  Relief of symptoms following trial of a reduced lactose intake also indicates lactose intolerance.
• A breath hydrogen analysis test is the gold standard, or method of choice, to diagnose lactose maldigestion, especially in children.  An increase in breath hydrogen concentration, generally 10 to 20 ppm above baseline, warrants a diagnosis of lactose maldigestion.
• A lactose tolerance test gives an oral dose of lactose equivalent to the amount of 1 quart of milk (50 g).  In the presence of lactose intolerance, the blood glucose level increases less than 25 mg/dL of serum above the fasting level, and gastrointestinal symptoms may appear.
• A biopsy of the intestinal mucosa to determine lactase activity.

    Congenital lactose intolerance is a rare condition.  It is commonly diagnosed during the newborn period by intestinal biopsy and enzyme assay.  Congenital lactose intolerance can cause life-threatening diarrhea and dehydration in the newborn.  A lactose-free formula is indicated as soon as the diagnosis is made.

The Low-Lactose Diet can be planned to meet the Dietary Reference Intakes (DRIs) as outlined in the Statement on Nutritional Adequacy.  Adequate calcium can be obtained through the inclusion of dairy products, including cheese, yogurt, and milk or lactose-hydrolyzed milk.

    When dairy products are limited, adequate intake of calcium, phosphorus, vitamins A and D, and riboflavin may be difficult to obtain.  Because of the increased importance of calcium and its relationship to various diseases (eg, osteoporosis, hypertension) maintaining calcium intake of 1000 to 1300 mg/day for adults is a primary goal (4). Vitamin D fortified milk is the most dependable source of vitamin D.  A vitamin D supplement may be indicated if exposure to sunlight is not ensured and if other foods fortified with vitamin D are not included in the diet.

How to Order the Diet
Order as “ Lactose-Controlled Diet”.

Planning the Diet
The important consideration is how much lactose can be tolerated without developing intestinal symptoms. 

    Between 80% and 100% of people with lactase deficiency experience the symptoms described if they drink 1 quart of milk a day.  Research indicates that most people with low levels of lactase can comfortably ingest at least 1 cup (8 oz) of milk (12 g of lactose) with a meal and even 2 cups of milk in a day (5,6).  One study has found that people with lactose maldigestion can consume 1500 mg of calcium per day if the dairy products are distributed between the three meals and provided partially in the form of yogurt and cheese (2 cups of milk, 2 oz of cheese, and 8 oz of yogurt) (7).  Tolerance to milk products is greater when they are consumed with other foods and spaced throughout the day.  Whole milk is better tolerated than lower fat milk, and chocolate milk is better tolerated than unflavored milk (8,9).  Generally, cheeses and ice cream are better tolerated than milk because of its lower lactose content.  Adults with lactose intolerance can usually tolerate the amounts of milk in many prepared foods, such as breads, luncheon meats, and creamed foods, if these foods are given at intervals throughout the day.

    Milk contributes a number of important nutrients to the diet, and dairy products are a major source of calcium, protein, and riboflavin.  The maximum amount of milk products that can be taken without adverse effects should be included in the diet of persons with lactose maldigestion.  Tolerance to lactose can be improved by gradually increasing intake of lactose-containing foods such as dairy products (3).

    Commercial lactase enzyme preparations (eg, Lactaid® and Dairy Ease®) will hydrolyze 70% to 90% of the lactose in milk depending on the amount added.  Lactose-reduced milks (reduced-fat, nonfat, calcium-fortified, and chocolate) with 70% to 100% of their lactose hydrolyzed are available.  Lactose-reduced cottage cheese, pasteurized processed cheese, and some ice creams are available in some markets.  Lactaid® caplets and Dairy Ease® tablets, which can be taken before ingestion of milk or milk products, are also available.  Products made from soy, eg, tofu, calcium and vitamin fortified soy milk, tofu-based ice cream substitutes, and pasta entrees, are also available.

    The following ingredients contain lactose and can be identified on the product’s food label: (dry) milk solids/curds, casein, whey (solids), and lactose.

    Other compounds that may appear on the food label but do not contain lactose are calcium compounds, kosher foods marked “pareve” or “parve,” lactate, and lactic acid.

LACTOSE CONTENT OF MILK PRODUCTS

 a These foods are processed with small amounts of milk, milk products, milk solids, or lactose and can be considered to have minimal to undetectable amounts of lactose.
b Only yogurt with active cultures is well tolerated by persons with a lactase deficiency.  Yogurt with active cultures is labeled “live and active culture.”

FOOD GUIDE — LACTOSE-CONTROLLED

a Only yogurt with active cultures is well tolerated by persons with a lactase deficiency.  Yogurt with active cultures is labeled “live and active culture.”

SAMPLE MENU

References

1. Inman-Felton A. Overview of lactose maldigestion (lactose nonpersistence). J Am Diet Assoc. 1999;99:481-489.
2. Lactose Intolerance. Washington, DC: National Digestive Disease Information Clearinghouse; 1994. NIH Publication No. 94-2751.
3. McBean LD, Miller GD. Allaying fears and fallacies about lactose intolerance. J Am Diet Assoc. 1998;98:671-676.
4. Yates AA, Schlicker SA, Suitor CW. Dietary Reference Intake: The new basis for recommendations for calcium and related nutrients, B vitamins and choline. J Am Diet Assoc. 1998;98:699-706.
5. Suarez F, Savaiano D, Levitt MD.  A comparison of symptoms after the consumption of milk or lactose-hydrolyzed milk by people with self-reported severe lactose intolerance. N Engl J Med. 1995;333:1-4.
6. Suarez F, Savaiano D, Arbisi P, Levitt MD. Tolerance to the daily ingestion of two cups of milk by individuals claiming lactose intolerance. Am J Clin Nutr. 1997;65:1502-1506.
7. Suarez F, Adshead J, Furne J. Levitt MD. Can lactose maldigesters tolerate the ingestion of a dairy-rich diet containing approximately 1500 mg calcium/day? New Orleans, La: American Gastroenterological Association Digestive Disease Week Syllabus. 1998;A-520, #2086.
8. Dehkordi N, Rao DR, Warren AP, Chawan CB. Lactose malabsorption as influenced by chocolate milk, skim milk, sucrose, whole milk, and lactose cultures. J Am Diet Assoc. 1995;95:484-486.
9. Hertzler SR, Levitt MD, Savaiono PA. Colonic adaptation in the daily lactose feeding in lactose maldigesters reduces lactose intolerance. J Am Clin Nutr. 1996;64:1232-1236.

Bibliography

Escott-Stump S. Nutrition and Diagnosis-Related Care. 5th ed. Baltimore, Md: Lippincott Williams & Wilkins; 2002. 
Hermans MM, Brummer RJ, Ruijgers AM, Stockbrugger RW. The relationship between lactose tolerance test results and symptoms of lactose intolerance.  Am J Gastroenterol 1997;92:981-984.
Hetzler S, Huynh BL, Savaiano DA. How much lactose is low lactose? J Am Diet Assoc. 1996;96:243-246.
Lactose-controlled diet. Manual of Clinical Dietetics. Chicago, Ill: American Dietetic Association; 1996.
Lactaid. Available at: http://www.jnj.merck.com. Accessed April 28, 1998.
Lee MF, Krasinsk SD. Human adult-onset lactase decline: an update. Nutr Rev. 1998;98:1-8.
Lin MY, Yen CI, Chen SH. Management of lactose maldigestion by consuming milk containing lactobacilli. Dig Dis Sci. 1998;43:133-137.
Beyer PL. Medical nutrition therapy for lower gastrointestinal tract disorders. In: Mahan KL, Escott-Stump S, eds. Krause’s Food, Nutrition and Diet Therapy. 10th ed. Philadelphia, Pa: WB Saunders; 2000:679-680. 
National Digestive Diseases Information Clearinghouse. Lactose intolerance. Available at: http://www.gastro.com. Accessed April 28, 1998.
Ramirez FC, Lee K, Graham DY.  All lactase preparations are not the same: results of a prospective, randomized, placebo-controlled trial. Am J Gastroenterol. 1994;89:566-570. 
Savaiano DA, Abou A, Anouar EI, Smith DE, Levitt MD. Lactose malabsorption from yogurt, pasteurized yogurt, sweet acidophilus milk, and cultured milk in lactase-deficient individuals. Am J Clin Nutr. 1984;40:1219-1223.
Vesa TH, Korpela RA, Sahi T. Tolerance to small amounts of lactose in lactose maldigesters. Am J Clin Nutr. 1996;64:197-201.

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