lactose intolerance


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Related to lactose intolerance: irritable bowel syndrome, Gluten intolerance

Lactose Intolerance

 

Definition

Lactose intolerance refers to the inability of the body to digest lactose.

Description

Lactose is the form of sugar present in milk. The enzyme lactase, which is normally produced by cells lining the small intestine, breaks down lactose into substances that can be absorbed into the bloodstream. When dairy products are ingested, the lactose reaches the digestive system and is broken down by lactase into the simpler sugars glucose and galactose. The liver changes the galactose into glucose, which then enters the bloodstream and raises the blood glucose level. Lactose intolerance occurs when, due to a deficiency of lactase, lactose is not completely broken down and the glucose level does not rise. While not usually dangerous, lactose intolerance can cause severe discomfort.
From 30 to 50 million Americans suffer from the symptoms of lactose intolerance, but not everyone who is deficient in lactase experiences symptoms. Experts believe that 75% of the adult population worldwide does not produce enough lactase and is at risk for some or all of the symptoms of lactose intolerance.

Causes and symptoms

Lactose intolerance can be caused by some diseases of the digestive system and by injuries to the small intestine that result in a decreased production of lactase. While rare, some children are also born unable to produce the enzyme. For many, however, lactase deficiency develops naturally because, after about two years of age, the body produces less lactase.
Symptoms include nausea, cramps, diarrhea, bloating and gas. The symptoms usually occur between 30 minutes to two hours after eating or drinking lactose-containing foods.

Diagnosis

Usually, health care professionals measure the absorption of lactose in the digestive system by using the lactose tolerance test, hydrogen breath test or stool acidity test. Each of these can be performed outpatient, through a hospital, clinic or doctor's office.
People taking the lactose tolerance test must fast before being tested. They then drink a lactose-containing liquid for the test and medical personnel take blood samples during the next two hours to measure the patient's blood glucose level. The blood glucose level, or blood sugar level, indicates how well the body is digesting the lactose. A diagnosis of lactose intolerance is confirmed when blood glucose level does not rise. This test is not administered to infants and very young children because they are more prone to dehydration, which can result from diarrhea from the liquid.
Health care professionals measure the amount of hydrogen in the breath using the hydrogen breath test. Hydrogen is usually detected only in small amounts in the breath. However when undigested lactose found in the colon is fermented by bacteria, hydrogen in the breath is produced in greater quantities. The hydrogen is exhaled after being absorbed from the intestines and carried through the bloodstream to the lungs. The hydrogen breath test involves having the patient drink a lactose-containing beverage. Health care professionals monitor the breath at regular intervals to see if the hydrogen levels rise, which indicates improper lactose digestion. People taking the test who have had certain foods, medications or cigarettes before the test may get inaccurate results. While the test is available to children and adults, newborns and young children should not have it because of the risk of dehydration from drinking the beverage that can cause diarrhea in those who are lactose intolerant.
A stool acidity test measures the amount of acid in the stool. This is a safe test for newborns and young children. The test detects lactic acid and other short-chain fatty acids from undigested lactose fermented by bacteria in the colon. Glucose might also be in the stool sample, resulting form unabsorbed lactose in the colon.

Treatment

Pediatricians might recommend that parents of newborns and very young children who are suspected of having lactose intolerance simply change from cow's milk to a soya formula. Since there is no treatment that can improve the body's ability to produce lactase, lactose deficiency treatments instead, are focused on controlling the diet.
Most people affected by lactose intolerance do well if they limit their intake of lactose foods and drinks. People differ in the amounts they can handle before experiencing symptoms. Some have to stop lactose completely. People who are sensitive after ingesting small amounts of lactose can take lactase enzymes, which are available without a prescription. Using the liquid form, people can add a few drops in their milk, put the milk in the refrigerator and drink it after 24 hours, when the lactase enzymes have worked to reduce the lactose content by 70%. If the milk is heated first and double the amount of lactase liquid is added, the milk will be 90 percent lactose free. Recently, researchers have developed a chewable lactase enzyme tablet. By taking three to six tablets just before eating, the tablets help people digest lactose-containing solid foods. Supermarkets also carry lactose-reduced mild and other products, which contain the needed nutrients found in the regular products but without the lactose.
Foods that contain lactose are milk, low-fat milk, skim milk, chocolate milk, buttermilk, sweetened condensed milk, dried whole milk, instant nonfat dry milk, low-fat yogurts, frozen yogurts ice cream, ice milk, sherbet, cheese, cottage cheese, low-fat cottage cheese, cream and butter. Other foods that may contain hidden lactose are: nondairy creamers, powdered artificial sweeteners, foods containing milk power or nonfat milk solids, bread, cake, margarine, creamed soups, pancakes, waffles, processed breakfast cereals, salad dressings, lunch meats, puddings, custards, confections and some meat products.

Prognosis

Lactose intolerance is easy to manage. People of all ages however, especially children, have to replace the calcium lost by cutting back on milk products by taking supplements and eating calcium-rich foods, such as broccoli, kale, canned salmon with bones, calcium-fortified foods and tofu. Many people who suffer with lactose intolerance will be able to continue eating some milk products. The condition is not considered dangerous.

Prevention

Often, lactose intolerance is a natural occurrence that cannot be avoided. However, people can prevent symptoms by managing the condition with diet and lactase supplements.

Key terms

Galactose — Simple sugar derived from milk sugar.
Glucose — A simple sugar and the chief energy source in the body.
Lactase enzyme — The enzyme produced by cells that line the small intestine which allows the body to break down lactose.
Lactose — The primary sugar in milk.

Resources

Organizations

American Dietetic Association. (800) 366-1655. 〈http://www.eatright.org/nfs/nfs43.html〉.

Other

"Lactose Intolerance." Onebody.com. 〈http://www.onebody.com〉.

intolerance

 [in-tol´er-ans]
inability to withstand or consume; inability to absorb or metabolize nutrients.
activity intolerance a nursing diagnosis accepted by the North American Nursing Diagnosis Association, defined as a state in which a person has insufficient physiological or psychological energy to endure or complete necessary or desired daily activities. Causes include generalized weakness, sedentary lifestyle, imbalance between oxygen supply and demand, and bed rest or immobility. Defining characteristics include verbal report of fatigue or weakness, abnormal heart rate or blood pressure response to activity, exertional discomfort, and dyspnea.
carbohydrate intolerance inability to properly metabolize one or more carbohydrate(s), such as glucose, fructose, or one of the disaccharides.
disaccharide intolerance inability to properly metabolize one or more disaccharide(s), usually due to deficiency of the corresponding disaccharidase(s), although it may have other causes such as impaired absorption. After ingestion of the disaccharide there may be abdominal symptoms such as diarrhea, flatulence, borborygmus, distention, and pain. One common type is lactose intolerance.
drug intolerance the state of reacting to the normal pharmacologic doses of a drug with the symptoms of overdosage.
exercise intolerance limitation of ability to perform work or exercise at normally accepted levels, as measured in exercise testing.
glucose intolerance inability to properly metabolize glucose, a type of carbohydrate intolerance; see diabetes mellitus.
lactose intolerance a disaccharide intolerance specific for lactose, usually due to an inherited deficiency of lactase activity in the intestinal mucosa.
risk for activity intolerance a nursing diagnosis accepted by the North American Nursing Diagnosis Association, defined as the state in which an individual is at risk of having insufficient physiological or psychological energy to endure or complete required daily activities. See also activity intolerance.
Patient Care. Nursing activities and interventions are aimed at identifying those factors that contribute to activity intolerance, providing evidence of the patient's progress to the higher level of activity possible for the patient, and reducing signs of physiologic intolerance to increased activity (blood pressure and respiratory and pulse rates). Once the contributing factors are identified, plans are made to avoid or minimize them. For example, if inadequate sleep or rest periods are a factor, the nurse plans with the patient scheduled periods of uninterrupted rest during the day. Inadequate sleep at night should be assessed and appropriate interventions planned and implemented. Making an objective record of the patient's progress toward increased activity tolerance can help alleviate depression or lack of incentive, both of which can be contributing factors. Such assessment data could include measurements of blood pressure, pulse, and respiratory rates before and after an activity, gradual increase in the distance walked, and gradual resumption of responsibility for activities of daily living.

lac·tose in·tol·er·ance

a disorder characterized by abdominal cramps and diarrhea after consumption of food that contains lactose (for example, milk, ice cream); believed to reflect a deficiency of intestinal lactase; may appear first in young adults who had tolerated milk well as infants.

lactose intolerance

A term that encompasses an array of adverse responses to consumption of non-human milk, in particular the inability to digest lactose, a sugar in milk and many dairy products. Up to 75% of adults have a decrease in lactase with age, which presents clinically as abdominal bloating, cramps, flatulence, diarrhea, nausea and/or vomiting, and borborygmi (a rumbling noise of the intestines).

lactose intolerance

β-d-galactosidase deficiency, lactase deficiency Internal medicine An acquired, or AR condition characterized by an inability to digest lactose–often due to lactase deficiency, which may ↑ with age; LI is more common in African Americans, Native Americans, Mediterraneans, Asians, due to deficiency of lactase on intestinal brush borders Etiology GI disease–celiac sprue, viral or bacterial gastroenteritis, post-gastroduodenal surgery Clinical Abdominal bloating, nausea, cramps, flatulence, inability to metabolize disaccharides, resulting in osmotic diuresis, diarrhea, acidic stools Management Lactose restriction in diet unless pretreated with lactase; cultured milk products–eg, yogurt, buttermilk may be well tolerated. See Lactose, Lactose tolerance test.

a·dult lac·tase de·fi·cien·cy

(ă-dŭlt' lak'tās dĕ-fish'ĕn-sē)
A disorder involving onset of difficulties of ingesting lactase, with resulting milk intolerance and malabsorption, in adulthood. Inherited forms may not be manifested until adulthood; any process that damages the intestinal lining cells can cause lactase deficiency in adults.
Synonym(s): lactose intolerance.

lactose intolerance

The result of an insufficiency of the lactose-splitting enzyme lactase (beta-galacosidase) in the lining of the small intestine. Lactose in milk is acted on by gas-forming intestinal bacteria, causing abdominal discomfort, colicky pain and diarrhoea. Asian and African people who have undergone a change of diet to one with a higher lactose content are often affected in this way.

lac·tose in·tol·er·ance

(lak'tōs in-tol'ĕr-ăns)
Disorder characterized by abdominal cramps and diarrhea after consumption of food that contains lactose (e.g., milk, ice cream).

Patient discussion about lactose intolerance

Q. can you be lactose intolerant just in the morning? if i drink milk or eat a dairy product in the morning i get nausous, vomit and have diarehha. but i eat dairy products in the evening and im fine. is it possible to be lactose intolerant just in the morning?

A. Not that I'm aware of.. You are either lactose intolerant or you're not. However, it depends on how much dairy products you eat, and perhaps you consume more dairy products in the morning, on an empty stomach, where it all absorbs, where as in the evening you might eat less and combine it with other food. I would suggest you dicrease the total amount of dairy you eat, in order to get rid of these symptms.

Q. lactose intolerant If you are lactose intolerant and you consume a dairy related product can it cause a fever?

A. No
Lactose Intolerance means you lack the enzyme to digest milk.
You get diarrhea NOT fever
DrMDK

Q. I am lactose intolerant. Can I have any other dairy food?

A. If you are lactose intolerant then you must avoid all lactose containing foods like milk, yoghurt & cheese. You can consume these dairy products If your intolerance is less or else you can have cultured yoghurt and lactobacillus milk as a better dairy option.

More discussions about lactose intolerance
References in periodicals archive ?
Possible explanation for this was the other possible causes of infant colic apart from lactose intolerance. This trial only investigated infant colic due to transient lactose intolerance caused by lactase enzyme deficiency.
A reduction of at least 50% of enzyme activity is required to trigger the symptoms resulting from the primary deficiency of lactase, which explains part of the variation in tolerance to small doses of lactose by individuals with lactose intolerance. Another possible explanation is the adaptation of the intestinal microbiota (11).
Lactose intolerance occurs frequently in children with nontyphoidal Salmonella gastroenteritis.
RP-G28 has the potential to become the first US FDA-approved drug for lactose intolerance, which affects more than one billion people worldwide.
CAUSES OF LACTOSE INTOLERANCE. Lactase deficiency is largely inherited (congenital and familial deficiency), though a condition known as secondary lactase deficiency can result from inadequate lactase production and can be caused by a problem with the small intestine, such as surgery, or another condition, such as Crohn's disease, ulcerative colitis, chemotherapy, celiac disease, or gastroenteritis.
Short-term and long-term ingestion of lactose and bacteria in the fermented milk product may affect the intestinal pH and other variables of the intestinal milieu, the intestinal micro flora, lactose fermentation, or the sensitivity of the subject to gastrointestinal disorders and may thus alleviate symptoms of lactose intolerance or other gastrointestinal disorders.
That is, if she really enjoys it and can tolerate it without developing signs of lactose intolerance. Of course, making sure she gets enough exercise and is receiving the correct amount of balanced food is also very important in avoiding obesity.
Additionally, in societies where milk consumption is continuous, people do not develop lactose intolerance despite their genetic predisposition.
People with lactose intolerance have to carefully avoid milk products to prevent diarrhea, gas, nausea, abdominal bloating, and cramps.
The Question: Does consumption of raw milk lessen the symptoms of lactose intolerance?
In fact, the National Institutes of Health (NIH), in their most recent consensus statement on the subject, specifically recommends that milk and milk products not be avoided by those with lactose intolerance as they provide important nutrients and confer several health benefits.
Lactose intolerance is an example of a food intolerance where the body struggles to digest lactose.