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Month: January 2011

Allergy vs. lactose intolerance

Allergy vs. lactose intolerance

Dear Dr. K:  I’m pretty sure I’m allergic to milk because it always gives me gas and diarrhea, but my allergy test to milk was negative.  What gives?

In all likelihood you have lactose intolerance due to lactase deficiency.  Lactose is the carbohydrate milk sugar which is a disaccharide “two-sugar”.  It consists of the monosaccharide glucose bound to the mono-saccharide galactose.  Unlike the bovine intestinal track which can absorb disaccharides, the human intestines can only absorb monosaccharides. 

Lactase is the enzyme found on the brush border in the intestines where the two sugars split, and lactose intolerance occurs when there is a complete or partial absence of the lactase enzyme.

Later symptoms will occur when the amount of lactose ingested exceeds the amount of enzyme present. 

When sugars are not broken down and absorbed in the intestine they hit the bacteria-filled colon where they are fermented.  This process of fermentation leads to gas and intestinal irritability.

In most people lactase deficiency is partial and therefore they can tolerate modest amounts of lactose.  Also, lactase enzyme is available as an over-the-counter, self-help remedy to be taken with any cow milk product.  To be successful, the dose of “lactaid” has to be titrated to the lactose load present in the meal.

Probiotics can also help the healthy

Probiotics can also help the healthy

Dear Dr. K:  You’ve written about using probiotics to help eczema.  Is there any value for a completely healthy person to take probiotics?

The simple answer to your question is yes.  There are many reasons why the answer is yes, as research on human gut flora is one of the hottest fields in academia right now.

First, a few simple statistics:  The adult human body is composed of about 10-trillion cells, but is colonized by some 100-trillion bacterial cells.  There are about 30,000 bacterial species living in the human GI tract, about 300 species in the mouth, about 100 species living on the skin.

All told, there are only about 100 bacterial species in the world that actually cause disease in humans.  In other words, an overwhelming majority of bacteria are well-behaved and do not make us sick.  Moreover, they may actually help us against the renegade bacteria.  This is certainly true in the GI tract.

Unfortunately, the typical American diet can jeopardize the friendly bacteria.  Many of our food sources contain chemicals and antibiotics that kill the friendly bacteria.  The paucity of fresh fruits and vegetables in the typical American diet – and their replacement by processed foods high in sugars and fat – also negatively impact the gut flora.

Renegade bacteria can learn bad behavior from gut flora.  One example is how Legionella learned to live inside of amoeba.  This led to an adaptive change that allows Legionella to live inside human macrophanges, cells that kind of look like amoeba, but are normally responsible for engulfing and killing bacteria.

Another example is the bacteria H. pylori which causes stomach ulcers, and which, by “criminal association” with other unhealthy GI bacteria has learned to release an enzyme, urease, which blocks the stomach acid that would normally kill the H. pylori.  It also excretes a protein, CagA, that allows it to attach to and enter stomach cells, thus hiding from immune destruction.

However, H. pylori bacteria that haven’t associated with the “criminal element” don’t cause illness.

The bottom line is that the healthier the gut flora, the healthier the individual.  Probiotics are excellent means to this end.

Quick Tips – Sleep Apnea

Quick Tips – Sleep Apnea

Researchers in Brazil studied the benefit of oropharyngeal exercises for patients with sleep apnea.  The exercises were taught by a sleep pathologist.  They consisted of exercises for the soft palate, tongue, and facial muscles.  The treated patients reportedly experienced a 50 percent improvement in their sleep disorder.

Asthma study shows common airway barrier, adds to bank of asthma knowledge

Asthma study shows common airway barrier, adds to bank of asthma knowledge

Last month the lead article in the New England Journal of Medicine was titled “A Large-Scale, Consortium-Based Genome-Wide Association Study of Asthma”, and was from work done by the National Heart and Lung Institute in the U.K.

It was a detailed, in-depth study that led to two major findings: First, asthma is genetically heterogenous.  This fact accounts for the variability in the illness itself, and also to the variability in response to treatments.  That is, when an inhaler that works beautifully in one asthmatic fails to help a second person, the reason may well be that they have two different asthmatic illnesses based on genetics.

On thing in common for all the asthma genes is that they all seem to lead to a defect in the epithelial barrier of the airways.  This faulty barrier leads to damage from the adaptive immune system, and the resultant airway inflammation.  Reason?  Because viruses, bacteria and allergens can more easily invade these porous airways.

The second finding was that elevated levels of IgE are not the seminal cause for asthma, but rather occur in response to this airway porosity with resultant greater exposure to allergens.

Still, this finding does not negate the fact that therapies directed at elevated IgE are exceedingly helpful in treating asthma.

This research will lead to greater efforts at altering gene defects, and also at means to improve the airway epithelail barrier function.

Vaso-active amines can cause copy-cat allergy symptoms

Vaso-active amines can cause copy-cat allergy symptoms

The result of certain substances (tyramine and other amines) releasing epinephrine (adrenaline) from nerves in the human body can lead to a variety of symptoms which can mimic allergy.  These sometimes frightening symptoms can include: hypertension, sweating, chest fullness, flushing, headache and palpitations.

A number of popular foods contain these amines: cheeses (the “riper the worser”), herring, sausage, bologna, salami, pepperoni, wine, sherry, banana, avocado, figs, chocolate and fava beans.

Lyme or lime, rash no fun

Lyme or lime, rash no fun

Lyme disease from ticks starts with a rash.  Phytophotodermatitis is caused by limes of the citrus version.

Limes contain psoralen, a chemical that absorbs long-wave ultraviolet light.  The light waves excite the electrons in the psoralen to three times their normal energy state.  When they release this energy it literally burns the skin and results in a red, itchy rash with blistering.

Other foods that contain psoralen include lemons, parsley, celery, carrots, figs, fennel and parsnip.  In fact, another term for phytophotodermatitis is “grocery clerk’s hands”.

This name alludes to the fact that it is skin contact from handling or preparing the food that leads to the localized rash; not ingesting the food.

Quick Tips – Vitamin D

Quick Tips – Vitamin D

A study in Finland demonstrated reduced chance for winter respiratory infections by taking vitamin D supplements.  Because of its northern climate, vitamin D levels fall in winter in Finland.  Vitamin D is known to help a variety of immune functions in addition to its benefit for bones.

For sufferers of chronic hives Vitamin D scores again

For sufferers of chronic hives Vitamin D scores again

Researchers at Vanderbilt University have made some interesting findings in their patient population with chronic urticaria.

Urticaria is the medical term for hives.  It can occur as an acute problem or as a chronic one.  Acute hives are usually due to a medicine reaction, insect bite or a food allergy.  Chronic hives are more difficult to classify as to cause.  Sometimes the cause is readily identifiable, but sometimes it isn’t.

What the scientists at Vanderbilt have discovered is that there is a certain percentage of people with chronic hives, (urticaria), who are vitamin D deficient.  Moreover, their hives resolve when their Vitamin D is brought back into the normal range.

Vitamin D acts on cells through a nuclear receptor called the Vitamin D receptor (VDR), which controls the activity of more than 50 genes.

One of these is the gene that controls T regulatory cells, and thus, can have a profound effect on immune function.  Improving this gene function allows the “righting of the immune ship”, thus healing the chronic hives.