Does your stomach churn after you drink milk? Do you have
diarrhea soon afterward? If so, you may be lactose intolerant.
According to the National Institute of Diabetes and
Digestive and Kidney Diseases (NIDDK) of the National Institutes of Health (NIH),
30 to 50 million Americans are lactose intolerant.
Being lactose intolerant means you can't digest lactose the
natural sugar found in milk and other dairy products. People who cannot digest
lactose have a shortage, or deficiency, of an enzyme called lactase, which is
produced in the small intestine. Lactase breaks down milk sugar into two
simpler forms of sugar, which are then absorbed into the bloodstream.
Intolerance is Not Allergy
Lactose intolerance is not the same as a milk allergy, says
Kavita Dada, Pharm.D., a senior health promotion officer in the Food and Drug
Administration's (FDA's) Division of Drug Information. "For most people
with lactase deficiency, it's a discomfort."
But a food allergy is an abnormal response to a food triggered
by the immune system and can be life threatening. People with food allergies must
avoid certain foods altogether. People with food intolerances can often eat
small amounts of the offending foods without having symptoms.
Symptoms:
When there is not enough lactase to digest the lactose in
the foods a person eats or drinks, the person may have
- gas
- stomach cramps
- bloating
- nausea
- diarrhea
These symptoms occur within 30 minutes to two hours after
consuming food containing lactose. Some illnesses can cause these same
problems, but a health care professional can do tests to see if the problems
are caused by lactose intolerance or by another condition.
Who Becomes Lactose Intolerant?
Lactose intolerance is more common in some ethnic groups
than others. NIDDK estimates that up to 75% of all adult African Americans and
Native Americans and 90% of Asian Americans are lactose intolerant.
As people age, their bodies produce fewer lactase enzymes,
so most people don't have symptoms until they are adults.
Most people inherit the condition from their parents.
Lactose intolerance is not very common in children under two years of age,
unless the child has a lactase deficiency because of an injury to the small
intestine. If you think your infant or child may be lactose intolerant, talk to
your child's pediatrician.
Managing Lactose Intolerance
There is no treatment to make the body produce more lactase
enzyme, but the symptoms of lactose intolerance can be controlled through diet.
Most older children and adults do not have to avoid lactose
completely. People have different levels of tolerance to lactose. Some people
might be able to have a tablespoon of milk in a cup of coffee with little or no
discomfort. Others have reactions that are so bad they stop drinking milk
entirely. Some people who cannot drink milk may be able to eat ice cream and
yogurt both which have less lactose than milk without symptoms. They may also be
able to consume a lactose-containing product in smaller amounts at any one
time.
Common foods with lactose are:
- milks, including evaporated and condensed
- creams, including light, whipping, and sour
- ice creams
- sherbets
- yogurts
- some cheeses (including cottage cheese)
- butters
Lactose may also be added to some canned, frozen, boxed, and
other prepared foods such as
- breads and other baked goods
- cereals
- mixes for cakes, cookies, pancakes, and biscuits
- instant potatoes, soups, and breakfast drinks
- lunch meats (other than Kosher)
- frozen dinners
- salad dressings
- margarines
- candies and other snacks
Dietary supplements with lactase enzyme are available to
help people digest foods that contain lactose. However, the Food and Drug Administration (FDA) has not formally
evaluated the effectiveness of these products, and you may want to ask your
doctor if these supplements are right for you.
Look at Labels
"Lactose-free" or "lactose-reduced" milk
and other products are widely available in grocery stores. These products may
be fortified to provide the same nutrients as their lactose-containing
counterparts.
There is no FDA definition for the terms "lactose
free" or "lactose-reduced," but manufacturers must provide on
their food labels information that is truthful and not misleading. This means a
lactose-free product should not contain any lactose, and a lactose-reduced
product should be one with a meaningful reduction. Therefore, the terms
lactose-free and lactose-reduced have different meanings, and a lactose-reduced
product may still contain lactose that could cause symptoms.
Lactose-free or lactose-reduced products do not protect a
person who is allergic to dairy products from experiencing an allergic
reaction. People with milk allergies are allergic to the milk protein, which
remains when the lactose is removed.
Look at the ingredient label. If any of these words are
listed, the product probably contains lactose:
- milk
- cream
- butter
- evaporated milk
- condensed milk
- dried milk
- powdered milk
- milk solids
- margarine
- cheese
- whey
- curds
Beware of foods labeled "non-dairy," such as
powdered coffee creamers and whipped toppings. Some of these foods may contain an
ingredient called caseinate, which comes from milk and contains lactose. Look
for "caseinate" or "milk derivative" on the label if you
are trying to avoid milk products.
Testing for Lactose Intolerance
A doctor can usually determine if you are lactose intolerant
by taking a medical history. In some cases, the doctor may perform tests to
help confirm the diagnosis. A simple way to test at home is to exclude all
lactose-containing products from your diet for two weeks to see if the symptoms
go away, and then reintroduce them slowly. If the symptoms return, then you
most likely are lactose intolerant. But you may still want to see your doctor
to make sure that you are lactose intolerant and do not have a milk allergy or
another digestive problem.
Tips for Consumers
If you are lactose intolerant, try lactose-free milk or
dairy products lower in lactose, such as yogurt and cheese. You may be able to
consume dairy products in small amounts without symptoms.
Consume milk or other dairy products with other foods. This
helps slow down digestion, making it easier for your body to absorb lactose.
If you're eating few or no dairy products, ask your doctor
or dietitian if you are getting enough calcium in your diet. You may need to
take dietary supplements with calcium to keep your bones healthy.
Raw Milk and Lactose Intolerance
FDA warns consumers not to drink raw, or unpasteurized,
milk. "Raw milk advocates claim that pasteurized milk causes lactose
intolerance," says John Sheehan, Director of FDA's Division of Plant and
Dairy Food Safety. "This is simply not true. All milk, whether raw or
pasteurized, contains lactose, and pasteurization does not change the
concentration of lactose nor does it convert lactose from one form into
another."
Raw milk advocates also claim that raw milk prevents or
cures the symptoms of lactose intolerance. Arguing that raw milk contains
Bifidobacteria, they claim these microorganisms are beneficial (probiotic) and
create their own lactase, which helps people digest the milk.
"This is not true, either," says Sheehan. "Raw milk can contain Bifidobacteria, but when it does, the bacteria come
from fecal matter (animal manure) and are not considered probiotic, but instead
are regarded as contaminants."
Drinking raw milk will still cause uncomfortable symptoms in
people who are correctly diagnosed as being lactose intolerant. But worse
than this discomfort are the dangers of raw milk, which can harbor a host of
disease-causing germs, says Sheehan. "These microorganisms can cause very
serious, and sometimes even fatal, disease conditions in humans."
Source: FDA/Center for Food Safety & Applied Nutrition
Read more: National Institutes of Health (NIH) - Lactose Intolerance
