Lactose
Intolerance
What is
lactose intolerance?
What are the symptoms of lactose intolerance?
Who is affected by lactose intolerance?
What causes lactose intolerance?
How is lactose intolerance diagnosed?
How can I treat the symptoms of lactose intolerance?
What kinds of foods besides diary products can
contain lactose?
How can I get enough calcium in my diet if I am
lactose intolerant?
Also
See:
Calcium
Intake
Osteoporosis
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What is lactose
intolerance?
Lactose intolerance
is a condition in which the body is not able to easily digest foods that
contain lactose, or the natural sugar that is found in dairy products.
Once lactose is in the body, it needs to be broken down into two simple
sugars, glucose and galactose, to be absorbed into the blood stream.
People who are lactose intolerant have a shortage of lactase enzymes that
break down lactose into these sugars.
What are the
symptoms of lactose intolerance?
Even though lactose
intolerance is not a dangerous health condition, the symptoms can be very
uncomfortable. Gas, bloating, stomach cramps, diarrhea, and nausea are the
most common symptoms. These symptoms may begin within as little as 30
minutes or up to two hours after eating or drinking foods that contain
lactose. The severity of symptoms is different for each person, and
depends on how much lactose a person can tolerate. Recent studies have
found that many people who have lactose intolerance can have one serving
of milk with a meal or two servings of milk per day, at separate times,
without experiencing symptoms. People also may be able to tolerate food
like aged cheese, which has less lactose, or yogurt, which has bacteria
that digests lactose. Some experts believe that people who are sensitive
to milk products, but can digest them in small quantities without
experiencing severe gastrointestinal symptoms, are not lactose intolerant,
but have lactose maldigestion. These people may produce lactase in very
small amounts, but enough to allow them to digest very small amounts of
dairy products.
Who is affected
by lactose intolerance?
An estimated 30 to
50 million Americans (about 25% of the United States population) are
affected by lactose intolerance. While this condition is least common
among Caucasians (about 15% of adults), it is widespread among other
ethnic groups. It is estimated that 70% of African-American, 74% of Native
American, 53% of Mexican-American, and 90% of Asian American adults are
affected.
What causes lactose
intolerance?
In most cases,
lactose intolerance develops slowly over time. In many people, the body
begins to produce less lactase beginning around two years old. As these
people become older, they lose the ability to produce lactase, but
symptoms of lactose intolerance may not appear until well after childhood.
No one knows why this occurs. In other cases, certain digestive diseases
or injuries to the small intestine can cause lactose intolerance. Both can
reduce the amount of lactase produced by the lining of the small
intestine. Another very rare cause is being born without the ability to
produce lactase.
How is lactose
intolerance diagnosed?
If you think that
you are lactose intolerant, it is important to have a doctor diagnose you
because your symptoms could be a sign of a different, or more serious,
illness. There are three tests used to determine if a person has lactose
intolerance: the lactose tolerance test; the hydrogen breath test; and the
stool acidity test. All of these tests are performed on an outpatient
basis.
The lactose
tolerance test is a blood test that measures the amount of glucose in the
blood before and after the patient drinks a large amount of liquid
containing lactase. The patient is required to fast before the test. The
hydrogen breath test measures the amount of hydrogen in the breath. The
patient has to fast overnight and again at regular intervals after taking
a dose of lactose. If the lactose is not digested, it produces hydrogen
and other gases in the stomach. These gases travel through the body to the
mouth and can be detected in the breath. The stool acidity test detects
acids created by undigested lactose.
How
can I treat the symptoms of lactose intolerance?
There are simple
ways a person can deal with the uncomfortable symptoms of lactose
intolerance. Although there is no known way to increase the amount of
lactase in a person's body, there are supplements people can take before
eating or drinking dairy products. These lactase supplements come in both
liquid and pill form and are available over-the-counter at pharmacies and
grocery stores. Lactose-reduced products also are available for most kinds
of diary products, including milk, cheese, and ice cream.
The easiest and
least expensive way to control symptoms is to avoid foods containing
lactase. Adults can test the kinds and quantities of foods their systems
are able to handle, then avoid the foods and amounts that produce
bothersome symptoms. Infants and children, on the other hand, should not
be given food that contains lactose if they have an allergy to milk
products. Studies show that for people who have at least some lactase,
they can increase tolerance to dairy products by introducing them
gradually into the diet. Again, they also can eat more easily digested
dairy products such as yogurt and aged cheese.
What
kinds of foods besides diary products can contain lactose?
It is important to
read the label of ingredients on foods since many foods other than those
made with milk may contain lactose. Examples of these include: bakery
products; cereals; instant potatoes, soups, and breakfast drinks;
margarine; non-Kosher lunch meats; salad dressings; candies; mixes for
pancakes, biscuits, and cookies; artificial sweeteners; hot chocolate
mixes; cream cheese and peanut butter with milk solid filler; omelets,
scrambled eggs and soufflés at restaurants; and gelatins made with an
ingredient called carageenan. Many prescription drugs also contain
lactose. A pharmacist can answer specific questions about which drugs
contain lactose, but some of them include birth control pills and tablets
for stomach acid and gas.
How can I get enough calcium in my diet if I am lactose intolerant?
Calcium is necessary
for strong and healthy bones throughout life. A lack of calcium in the
diet can lead to osteoporosis, or a condition of fragile, weakened bones
that can break easily. Dairy products, like low-fat milk, are the best
source of calcium. If you are lactose intolerant, it is important to have
a diet that includes other foods high in calcium to meet the recommended
daily amounts.
Other foods high in
calcium include dark, green leafy vegetables, like kale and broccoli, fish
like salmon, sardines, and oysters (or those with soft, edible bones), and
tofu. Although these foods are high in calcium, the body cannot absorb it
as easily as from milk. For instance, it takes 11-14 servings of kale a
day to get the same amount of calcium in three to four glasses of milk.
Click here for more information on calcium.
Eating foods
fortified with calcium, like certain cereals and orange juice, and taking
calcium supplements also can help you reach your optimal calcium intake.
Since there are several types of calcium supplements available, you should
discuss the choice of supplements with your doctor. Taking lactase
supplements before meals and eating lactose-free products high in calcium
are other options.
from
The Office On Women's Health - US Department of Health and Human Services
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