Sunday, September 12, 2010

Allergies, Lactose Intolerance

Lactose Intolerance (hypolactasia)

he healthy small intestine is a barrier that separates the outside world environment from the body's internal environment. Its function is to selectively absorb healthy nutrients across the intestinal wall into the portal system, or the lacteal, into the intestinal lymphatic.

Four factors determine the small intestine's function:

1. Motility of the intestine is composed of two types of motilities: the gross motility of the intestine and the motility of the micro-villi. Motility helps nutrients to maintain contact with the epithelial cells of the intestine, influence absorption of such nutrients, and maintain one direction flow to prevent back up, (down gradient absorption), of the nutrients from portal system into the intestine.

2. Flora of the intestine is of great importance, not only for nutrient digestion but for nutrient

absorption.

3. Production of specific digestive enzymes which hydrolyse nutrients into smaller nutritional units, facilitate its absorption.

4. pH level of the intestinal acidity may determine whether absorption will take place or not.

The small intestine is imbalanced when one of its functions is disturbed.

Definition:

Lactose is a disaccharide, (two sugars), which is split into two monosaccharides, (single sugar), namely glucose and galactose, in order to be absorbed across the intestinal wall. An intestinal enzyme found in the brush borders of the microvilli of the epithelial cells is responsible for lactose hydrolysis into two single sugars. The enzyme is called Alpha-galactosidase, which is commonly known as lactase. Unlike other disaccharides which are hydrolyzed in the small intestine at a fast rate, lactose is hydrolyzed at a slower rate; therefore lactose production in the small intestine is governed by its hydrolysis rate. The byproducts of lactose hydrolysis, (glucose and galactose), are absorbed across the intestinal wall by active transport mechanism. This mechanism requires the body to spend energy because it moves the resultant two sugars uphill against concentration gradient. This means that the body must spend energy every time the individual uses dairy products.

Symptoms:

Within one hour of ingesting milk, the patient may produce one or more of the following symptoms:

flatulence, bloating, cramps, and/or diarrhea.

Deficiency of lactase:

The body may be deficient in lactase due to the following reasons:

1. Genetic factors permanently prevents the body from lactase synthesis. It is a genuine lactase deficient patient who needs to utilize exogenous lactase when ingesting dairy products. The alternative treatment to exogenous supplementation of lactase is to completely abstain from the usage of dairy products. Abstaining from dairy products consumption is the answer, not exogenous supplementation. Despite exogenous supplementation, repeated introduction of undigestible food would set the stage for the immune system to be triggered every time the individual eats such food. Some form of allergies would settle in the body sooner or later.

2. Inability of the intestinal brush borders of the epithelial cells to synthesis lactase. This is due to one of the following reasons:

a) poor dietary intake preventing the body from efficiently synthesizing lactase and;

b) bleaching the enzyme from the intestine due to excessive and prolonged use of dairy products.

This use would tax the body with high demand for lactase and reduce supply of nutrients to manufacture the enzyme. Many children in our society suffer from this problem.

3. Gastrointestinal diseases which result in intestinal mucosa damage such as:

- giardiasis

- cystic fibrosis

- regional enteritis

- ulcerative colitis

- tropical sprue

- nontropical sprue

- a beta lipoproteinemia

- viral and bacterial infections

4. Drug interactions: Some patients are using several medications for several ailments. Few of these drugs may interact producing an antagonistic factor that may hinder or stop the production of certain enzymes and hormones. Drug interactions are studied and listed individually; however, two or three drug interactions in the human body have not yet been studied.

Diagnosis:

Blood tests, stool tests, food elimination or food rotation are not a diagnostic tool to diagnose lactose deficiency. The only factor that can determine a patient's lactose deficiency is the patient's history of symptoms, duration of symptoms, and periodicity of symptoms. Proper symptoms and history taking are the keys to successful diagnosis and, consequently, a successful treatment. Any lab test is utilized to confirm the physician's suspicion.

Laboratory work:

1. Observation of symptoms

The patient ingests 200 ml of milk which contains approximately 10 g of lactose. Shortly thereafter, the patient presents symptoms such as flatulence, bloating and cramps, but no diarrhea. There is a strong probability that this patient is lactose intolerant.

2. Serum testing

The patient ingests an amount of lactose proportional to the patient's weight (1 g per kg of body weight). Shortly after ingestion, several blood samples are obtained from the patient at constant intervals to measure the rise in the total amount of glucose. In a positive case, the patient would produce flatulence, bloating, cramps, diarrhea and an increase in blood glucose greater than 20 mg/dl above the fasting level within 1 hour following milk ingestion.

3. Urine dipstick

A urine dipstick impregnated with galactose oxidase is used to test the patient's urine after ingesting 100 g of milk. A positive case would change the colour of the strip.

4. Breath test

The patient ingests 50 g of lactose. Shortly thereafter, the patient is given a container to blow in. In a positive case, hydrogen is released from the fermentation of unabsorbed lactose by colonic bacteria leading to intestinal symptoms and increase in hydrogen production.

5. Gallbladder integrity

It is very essential to check the integrity of the gall bladder as a possible cause of hypolactasia.

This test is reliable due to the following factors:

1. Sensitivity

2. Non-invasiveness

3. Independence from gastric emptying

4. Independence of metabolic factors

A study in 1978 by AD Newcomer, SF Hodgson, DB McGill, PJ Thomas was done to determine prevalence in osteoporosis and lactase deficiency. This test was utilized to study the link between idiopathic postmenopausal osteoporosis and lactase deficiency in females. The test indicated that approximately 25% of females in the study who were deficient in lactate had developed osteoporosis.

False negative results could be due to:

- Ascites

- Renal insufficiency

- Intestinal bacteria overgrowth.

- Drug administration such as aspirin and indomethacin

Genetic Prevalence:

High prevalence of lactase deficiency occurs in African Americans, Orientals, Jews and Native Americans

Treatment:

Lactase deficiency is treated according to its cause, not its symptoms. Dairy products are not mandatory for a healthy life. Other natural products such as vegetables and fruits may substitute for dairy product use.

On the other hand, for those who choose to take lactase supplementation without proper diagnosis it may not be in their best interest. Those patients whose bodies can not synthesize lactase due to genetic reasons are advised to abstain from dairy products. On the other hand, those who choose to play some tricks with their bodies may use supervised exogenous supplementation. Patients who have abused their bodies over the years with excessive dairy product consumption should abstain from dairy product consumption to rebuild their bodies reserve of lactase. Proper diet is mandatory for any patient who suffers with lactase imbalance.

In closing: Many patients claim that they have some allergies to dairy products. Simply, they base their statement on the fact that they react to dairy consumption by flatulence, bloating, cramps, and diarrhea.

Lactase deficiency is not an allergy.

Dr. Fateh Srajeldin N.D., B.Sc. 416-207-0207


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