Tuesday, 26 November 2013

Food allergies driving you nuts?

We were talking to a mum the other day who said that during her first pregnancy she ate plenty of eggs and her child was born with an egg allergy. Yes, may be a coincidence... but during her second pregnancy she took fish oil supplements and her baby was born with an allergy to fish. Yes, this may still be a coincidence but it did prompt lots of talk in the office about food allergies. 


"4.1 million Australasians have at least one allergic disease."

This is a frightening statistic by the Australasian Society of Clinical Immunology and Allergy (ASCIA) this year. An allergy is the immune system's response to a particular substance, which is mistakenly identified as toxic. This can literally be anything such as food, airborne particles, skin care products, medications or insect venom. The 2013 ASCIA report found that food allergies, particularly among children, are on the rise. Here are some other interesting facts released by the organisation: 

  • Allergy and immune diseases are 2 of the most rapidly growing chronic conditions in Australia 
  • 10% of infants in Australia have a food allergy 
  • Over the past 20 years, hospital admissions for anaphylaxis (most severe and potentially life threatening type of allergic reaction) have increased 4-fold 
  • ASCIA predicts that by 2050, the number of Australians with an allergy will increase by 70% (to 7.7 million people) as seen in the below chart


Is this rise in allergies thanks to a better healthcare system and easier methods of detecting allergies, OR is there more to it? There are so many interesting different food allergy theories floating around which I thought I'd share. 



Hygiene theory 

The base of this theory is that food allergies have come about due to a lack of microbial exposure ... in simpler terms we have become too clean for our own good. It was founded by David Strachan. 

Over the years, humans have worked to live in a sterile, clean environment and thanks to modern hygiene tools, we have done just that. Next time you walk through the detergent aisle of the supermarket, take a look at how many products say "Cleans 99% of germs." This theory suggests that by living in such an environment, we aren't exposing infants and toddlers (whose immune systems are still developing) to bad bacteria and germs. This means their immune systems aren't being taught what to attack and what is good and healthy. It then mistakes harmless things as invaders which need to be attacked and viola they are left with an allergy. 

Now this is not to say we should be living in a pig sty. But Strachan suggests we shouldn't sit in the other extreme either and allow children to 'explore' nature sometimes. Probiotics can be a way to introduce the body's immune system to a broad range of friendly bacteria. 

** Did you know? There are more bacteria cells in your body than human ones.


Lack of exposure to allergens AKA 'peanut allergy theory'

This was a theory mentioned to me by a doctor I know which suggests that allergies develop by not exposing infants to common allergens from an early age. Early consumption of peanuts in infancy is associated with a low prevalence of peanut allergy compared peanut allergies in UK Jewish children and Israeli children. In Israel, children consume peanuts from their first year of life whereas in the UK, it is recommended parents avoid giving children peanuts until later on in life as they are such a common allergen (this is also the case for North America and Australia). However, the study found that peanut allergies were actually more prevalent in Jewish children from the UK compared to Israeli children. 


Interestingly, this 2008 study looked at whether or not peanut allergies in children has anything to do with whether or not the mother consumed peanuts, or foods containing peanuts, during pregnancy or lactation. It found that a child was more likely to develop a peanut allergy if their mother consumed peanuts more than once a week throughout pregnancy compared to those whose mothers only consumed peanuts less than once a week during pregnancy. The study states "[Peanut allergy] is more likely to occur if mothers eat peanuts more frequently during pregnancy and introduce it early to the infant's diet."

This goes to show that our knowledge of what triggers allergies is still incomplete. 


The Western diet theory 

As the name implies, this theory suggests the Western diet is to blame for the rise in food allergies in first world countries. This diet, which is largely compromised of sugars, animal fats and calorie-dense foods, has resulted in less diversity of gut flora and good bacteria in the stomach. A study from the Proceedings of the National Academy of Sciences of the United States of America compared the Western diets of European children to those of children from a rural African village where the diet was very similar to that of early human settlement hundreds of years ago. They found vast differences in the gut flora and bacteria between the two groups. In European children that consumed a Western diet, where diversity of gut flora and bacteria was minimal, there was also a higher prevalence of food allergies compared to the rural African village. 


The vitamin D theory 

Research is beginning to unveil a link between a lack of vitamin D and food allergies among children. Along with strengthening our bones, vitamin D is also known for boosting the immune system too. According to a study by Murdoch Children's Research Institute, Australian infants that are vitamin D deficient were 3 times more likely to have a food allergy. The odd thing about this was it is only relevant for Australian infants. It also found that those living further from the equator had a higher chance of developing a food allergy. What makes researchers even more convinced with this theory is that over the years, Australians have become more conscious of sun protection (staying indoors, wearing sunscreen and hats, etc.) which has led to a deficiency in vitamin D. This decline in vitamin D exposure is paralleled to a rise in allergies across Australia. 


Antibiotics and allergies 

Long courses of antibiotics can kill good gut flora and allow an over proliferation of bad gut flora. These can produce toxins and make us more prone to allergies. Antibiotics are essential tools to manage disease, but must be taken with care (as advised by your doctor). Apparently, the use of antibiotics in early childhood is linked to higher chances of developing allergies or asthma (according to this 2000 study). This is partly to do with the young immune system not being given the chance to determine what to attack and what is good and healthy as the antibiotics kill off the 'invaders' as well as the good bacteria. 

There are so many food allergy theories out there and I could literally go on for ages. These are the ones that I found the most interesting but if you know of any theories, please share them in the comments below. :) 

By Daniella De Azevedo 

2 comments:

  1. No mention of the fact that our minerals are completely imbalanced. Most people have a completely wrong ratio of calcium to magnesium for example. Also no mention of the toxins we pump ourselves full of at a very young age, i.e. vaccines and medicines.

    ReplyDelete
  2. Impressive diet related information.. kind of weird though, I've never been the clean type, but suspect I may be allergic to some sort of food... oh well

    Thanks heaps
    http://www.mickowar.com

    ReplyDelete