Download LACTOSE INTOLERANCE Lactose intolerance is defined as the

LACTOSE INTOLERANCE
Lactose intolerance is defined as the development of gastrointestinal
symptoms associated with incomplete digestion of the milk sugar, lactose.
Lactose intolerance is caused by a relative deficiency of lactase, an
enzyme normally found in the brush border of the mucosal cells of the
proximal small intestine that hydrolyzes lactose into its monosaccharide
constituents, glucose and galactose. The condition can be congenital or
acquired, lifelong or transient.
SYMPTOMS OF LACTASE DEFICIENCY
Symptoms include bloating, cramps, diarrhea and flatulence, occuring 30
minutes to 4 hours after ingesting lactose-containing foods. The
symptoms are caused by the fermentation of unabsorbed lactose by colonic
bacteria to produce hydrogen gas and lactic acid.
The severity of symptoms is dependent on the degree of enzyme deficiency,
the amount of lactose ingested, and the presence of superimposed bowel
disease.
Acquired Lactose Deficiency Acquired lactose deficiency accounts for
most cases of lactose intolerance. The condition is found in most adult
populations throughtout the world. (50 million Americans)
Population
Prevalence of Lactose
Deficiency in Adults
Thias
97%
Filipinos
95%
Chinese
90%
Japanese
90%
Greeks
85%
Arabs
80%
Ashkenazic Jews
80%
Mexicans
75%
Black Americans
70%
Israeli Jews
60%
African Bantus
50%
White Americans
5-20%
British
5-8%
West Europeans (Danes, Swiss)
2-8%
In genetically predisposed persons, intestinal lactase begins to decline
at about age 4 to 5 years of age. Most susceptible individuals become
symptomatic by early adulthood.
DIETARY MANAGEMENT OF LACTOSE INTOLERANCE
In most cases, symptoms can be controlled easily by avoiding large
amounts of lactose-containing foods. Enlisting the aid of a dietitian
can be helpful in determining each individual's particular tolerance
level. Most adults with acquired lactase deficiency are able to tolerate
3-8 gm of lactose at a given time.
The lactose restricted diet limits intake of lactose to 8-10 gms/day.
The diet limits the qualities of milk and milk products consumes.
Lactose-Containing Food
Serving Size
Lactose Content
Whole milk
1 cup
11 gm
Low fat, skim milk
1 cup
9-14gm
Yogurt (plain)
1 cup
12 gm
Cottage cheese
1 cup
5-6 gm
Ice cream
1 cup
9 gm
Ice milk
1 cup
10 gm
Sherbet
1 cup
4 gm
Whipped cream
1 tbls
.4gm
Sour cream
4 oz
5 gm
Cheeses
1 oz
.5-1 gm
Butter
1 tbls
.15 gm
Food labels should be read carefully. The following ingredients signal
lactose-containing foods: milk, milk products, milk sugar, lactose, whey,
curds, caseinate. Lactose is also used as a base in certain prescription
and over-the-counter drugs. In very sensitive individuals, a pharmacist
should be consulted.
Hidden sources of lactose may be found in a variety of foods, including:
bread and other baked goods, processed breakfast cereals, instant
potatoes, soups, breakfast drinks, margarine, luncheon meats, salad
dressings, candies and other snacks, mixes for pancakes, biscuits and
cookies.
NUTRITIONAL CONSIDERATIONS
Lactose restricted diets may be deficient in calcium, vitamin D, and
riboflavin, particularly in persons with increased nutritional
requirements (children, adolescents, pregnant and lactating women).
The RDA for calcium can usually be met by consuming low-lactose foods
that are high in calcium, by eating cultured yogurt (contains both
lactose and lactase, the latter produced by bacterial cultures), by
taking calcium supplements, or by eating specially prepared dairy
products to which lactase is added.
Examples of foods with high calcium but no lactose include broccoli,
kale, turnip greens and other green vegetables, tofu, molasses, shrimp,
salmon and oysters.
Vitamin D and riboflavin replacement are not necessary in persons who
otherwise are exposed to the sun and who are eating otherwise wellbalanced diets.
LACTASE ADDITIVES
Lactase enzyme can be added to milk to predigest the lactose. The
contents from 1 or 2 lactase capsules (e.g., Lactrase) or 5 drops of
"Lactaid" liquid can be added to one quart of milk and stored in the
refrigerator for 24 hours. This can reduce the lactose content by 70%
without lowering its nutrient value. More complete breakdown can be
achieved with 2 to 4 Lactrase capsules or 15 drops of Lactaid.
Lactase supplements can also be ingested with meals containing lactose.
One to two Lactrase capsules, or 1/2 to 3 Lactaid caplets can be taken
just befor meals or snacks.
In most supermarkets, there are also availabe specially prepared lowlactose foods. Lactaid Milk is 70% lactose reduced. Other pretreated
foods include lactose-reduced ice cream, cottage cheese, and American
process cheese food. The milk may be slightly sweeter than untreated
milk but is palatable and well tolerated. Unpasturized cultured yogurt,
is high in lactose content, but also contains sufficient lactase produced
by the bacterial cultures. Pasturized yogurt is poorly tolerated because
the lactase is inactivated by the pasturization process.