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Mother’s milk, delayed solids: Food allergy prevention standards, but we can always learn from new data

Mother’s milk, delayed solids: Food allergy prevention standards, but we can always learn from new data

 This month’s issue of the Journal of Allergy and Clinical Immunology has a symposium on food allergy.

Until recently it has been recommended that a good strategy to reduce risk of children developing food allergy was to promote exclusive nursing as a food source, to have the mother avoid highly allergenic foods and to delay weaning with introduction of solid foods.

However, despite the implementation of this approach in a number of countries in Asia, Europe and North and South America, there has been no reduction in the incidence of food allergy. The recommendations were made based on individual facts that are true, but that unfortunately do not lead to the desired outcome.

It is definitely true that mother’s milk is the best and most complete of infant nutrition. It is also true that mother’s milk contains a host of proteins and immune globulins that provide protective immunity to the infant. It is also true that early exposure to foods other than mother’s milk can lead to the development of food allergy.

From all these facts it was assumed the feeding recommendations also would be the best course to follow.

Once the potential benefit of this dietary approach was actually studied however, it was quickly learned that it did not provide the desired results. As it turns out a crucial fact that was previously unknown makes a pivotal difference.

If infants have early exposure to non-breast milk foods through skin contact, this is what leads to allergic sensitization. This has been born out in animal model research. Paradoxically, the food allergy development through skin contact can actually be prevented by early oral exposure to the food, e.g., from parents’ hands, kisses, etc. A good example of this phenomenon has actually been recognized for quite some time and it has to do with nickel allergy.

If a child’s first exposure to nickel is from pierced ears (skin exposure), there is up to a 40 percent chance of the child developing nickel allergy. If, on the other hand the child has oral nickel exposure from placement of orthodontic braces prior to ear piercing, the risk of nickel allergy is almost zero.

At this point in time the American Academy of Allergy has no specific recommendation. There are, however, numerous randomized controlled studies that are being conducted comparing the early exposure to foods such as peanut, milk, wheat and egg versus strict avoidance of these foods. Such studies will lead to a new evidence-based recommendation on how to prevent food allergy.

Vaccine Research addresses serious worldwide uptick in food allergy

Vaccine Research addresses serious worldwide uptick in food allergy

Another part of the Journal of Allergy and Clinical Immunology’s food allergy symposium addressed European research on food vaccines. Impetus for this research is the worldwide increase in food allergy and also the increasing frequency of anaphylactic shock from food allergy.

Since vaccine therapy has proven successful in treating respiratory allergies and has also worked to prevent recurrent anaphylaxis from insects, it stands to reason that it could help eliminate food allergy and prevent food-related anaphylaxis.

Four types of vaccines for food allergy have been studied in Europe (and other countries): oral, sublingual, epicutaneous and subcutaneous.

All of these methods have proven to be of some benefit. Unfortunately, the ones that lead to the best improvement seem to have more side effects. Between the two ingestion vaccines (immunotherapy), oral immunotherapy leads to better reduction in allergy than sublingual.

The oral route commonly leads to GI side effects such as heartburn, nausea, vomiting, cramps and diarrhea. The sublingual route was much less likely to cause these symptoms, but did lead to itching and swelling in the mouth. Epinephrine shots had to be given twice as often for reactions in the oral group as compared to the sublingual group.

But patients who were successfully treated from both groups were able to ingest the implicated food – such as peanut – without going into allergic shock.

Subcutaneous immunotherapy, which is how traditional allergy shots are given, was more effective than epicutaneous immunotherapy. But once again, the more effective format led to more frequent vaccine reactions and to greater need for epinephrine to treat some of the reactions. When either of these techniques was successful, it again allowed the patient to safely ingest the offending food.

The European study group is conducting new and longer studies of these various forms of immunotherapy. The studies will include children, adolescents and adults. They also are adding studies to compare the use of pharmaceutical-grade food extracts versus the use of the entire native food as a vaccine substrate to see which works better and is safer.

Quick Tips – local honey

Quick Tips – local honey

The use of local honey has been recommended as a non-medicinal way of treating allergy.  As it turns out, it can either help or hurt. In order for “local honey” to actually help, it has to be taken in incrementally increasing doses, much the same way an allergy shot is built up. The benefit is extremely modest.  Remember, bees carry entomophilous pollen, whereas anemophilous (airborne) pollen accounts for most allergies. Just using regular amounts of honey on cereal or in tea can worsen allergy due to the random exposure to the pollen it contains.   

Vitamin E really not a ‘bad guy,’ but choose wisely

Vitamin E really not a ‘bad guy,’ but choose wisely

 Do you ever get confused over scientific advice about vitamins and supplements? Join the crowd.Vitamin E is probably a good example of good vitamins that have fallen into disfavor.Actually, vitamin E is still a very important vitamin and we should try to have replete dietary intakes of this vitamin. It turns out that the source of vitamin E is the confounding variable.

Vitamin E in supplements is mostly alpha-tocophenol, which blocks the effects of gamma-tocophenol. The alpha-tocophenol vitamin E is also a pro-oxidant, while the gamma form is a very potent anti-oxidant. It is found naturally in fruits, vegetables and other healthy foods.

Celiac disease control helps thyroid patients absorb meds

Celiac disease control helps thyroid patients absorb meds

 The American Journal of Medicine had an intriguing article about people with difficult-to-regulate thyroid disease.

Researchers at the University of Vermont studied patients with hypothyroidism (low-functioning thyroid) who were on thyroid replacement therapy. In many people it is easy to dial in the proper thyroid hormone regimen, but in some this can be very difficult.

When the Vermont researchers looked at this latter group they discovered a large number had previously undiagnosed celiac disease.

Since celiac disease alters absorption of nutrients it can also lead to poor absorption of medications.

Once the celiac disease was treated, the patients’ thyroid condition came under smooth control.

Dear Doc: Conference topics relate environment to children’s allergies, plus’ traffic cop Tregs’

Dear Doc: Conference topics relate environment to children’s allergies, plus’ traffic cop Tregs’

Dr. Patrick Klemawesch had the opportunity to attend the annual meeting of the American Academy of Allergy Asthma and Immunology (AAAAI) this month. This is the largest annual allergy conference — four days of lectures, seminars, and presentation of data from researchers and clinicians around the world.

Some of the most interesting research presented came from the Cincinnati Allergy and Air Pollution Study. Many studies are currently looking at the effects of people’s surroundings on their development of allergies and asthma. This is a unique project, because rather than starting with allergic kids and looking backward in time to try to root out causes, the study started following children at birth. “High-risk” kids (those with allergic and asthmatic parents) were enrolled in the study at birth and assessed annually.

One significant finding was that children of all ages had more frequent wheezing when exposed to diesel exhaust, and that the exposure was highest within 400 meters of a “stop-and-go” thoroughfare with bus and trucking routes. However, these effects did not imply higher risk of developing asthma. In fact, no environmental effect on the development of asthma was demonstrated. Re-analysis of the data did show one striking finding, though: obese children were more than twice as likely to develop asthma by age 7.

Another focus of the conference was on regulatory T cells, also called “Tregs.” These are the “traffic cops” of the immune system that act as brakes on inflammatory reactions. Since recent research has failed to show a correlation between a mother’s diet during pregnancy/ breastfeeding and the development of food allergy in her child (what the child is exposed to), researchers are shifting focus to other things that affect how the developing immune system responds to foods.

One hypothesis regarding the development of allergy is that the fundamental problem is a lack of appropriate Treg activity. Both Tregs and allergic-type T cells develop in the thymus, and the balance between the two can determine whether a person becomes allergic.

Mice allergic to egg protein can be given large amounts of egg without any reactivity if they are given infusions of Treg cells prior to an allergic challenge. Also, researchers have tried to stimulate mice to make higher levels of their own Tregs instead of infusing them.

One promising idea is the use of stem cells with allergy particles that come from our own body combined with the cell membrane. Peanut-allergic mice that were given “peanut-labeled” stem cells developed Tregs specific for the peanut protein and then tolerated peanut exposure without anaphylaxis. Furthermore, their levels of peanut-specific IgE (allergic antibody) seem to have been driven down significantly by the Tregs that they developed.

Preliminary research is being done on other things that affect levels of Tregs in a developing baby. Cigarette smoke, viral infections and certain pollutants can all affect the developing thymus. Interestingly, fatty acid and fiber content of the maternal diet may play a significant role in the allergic/Treg balance in the developing thymus. It is too early to recommend fish oil supplements to all pregnant or nursing moms, but the research is ongoing.

Food choices vs. kids’ allergy/asthma:

Food choices vs. kids’ allergy/asthma:

The British Medical Journal recently published the results of a huge international study on allergy termed ISAAC (International Study of Allergies and Asthma in Children). The study was undertaken to evaluate the effects of dietary choices on asthma and allergy. The findings were rather startling.

Basically, a healthy diet prevented problems and an unhealthy diet led to problems. There was a very strong preventive benefit from regular consumption of fruits and green vegetables. Both are a rich source of antioxidants which are known to have a beneficial effect on the immune system. Regular fish consumption was also associated with lower incidence of allergy and asthma.

On the other hand, diets rich in fat led to allergy and asthma. Especially bad in this regard were fast foods such as burgers, fries and sodas. Saturated fatty acids destabilize the immune system, whereas N-3-polyunsaturated fatty acids (found in fish) have natural anti-inflammatory properties.  

The investigators concluded that the “Mediterranean diet” is a model diet for general and allergic health. The Mediterranean diet is high in fruits, vegetables, fish, olive oil, tomatoes, grape/raisin products, and nuts.

Bird Flu Research

Bird Flu Research

Maelstrom in scientific media prompts concernwith precipitous release of bird flu research   Despite warnings from many medical and scientific groups, “New Scientist” recently published the article, “Five easy mutations to make bird flu a lethal pandemic.”

Two different research groups have engineered the H5N1 virus which is highly communicable between ferrets (the most reliable animal surrogate for human flu). Should this avian virus “get loose,” it would probably kill 20 percent of the world’s population.

Medical and scientific groups had lobbied to withhold precise details on the experimental work, but sadly, these cautions were not heeded.

Hopefully the same global restraint that has prevented post-WWII use of nuclear weapons will prevail with regard to this new discovery.

Quick Tips – Pollen and dogs

Quick Tips – Pollen and dogs

Remember that if you open your windows, even briefly, during our clement spring days, it takes 24-36 hours of HVAC circulation to filter the air back to “indoor quality.”

To reduce the tracking in of pollen on dog feet, have them dip their paws in a pan of water and dry them off as they return from their “potty sorties.”