As many of you guessed in our Facebook trivia giveaway, food allergies in the US have increased by 50% between 1997 and 2011, according to a 2013 study published by the Centers for Disease Control and Prevention. Researchers estimate that up to 15 million Americans currently have food allergies, and 1 in every 13 children is affected. That’s roughly two in every classroom!
And that’s just food allergies. There are a lot more people that have food intolerances, a number which is hard to measure accurately. What’s the difference? While both may produce similar symptoms such as stomach pain, bloating, and fatigue, a food allergy is an abnormal response to a food that is triggered by the immune system. The immune system is not responsible for the symptoms of a food intolerance. In addition, food allergic reactions may be caused by exposure to microscopic amounts, including touching or inhaling the food, and can cause additional symptoms such as skin rashes, difficulty breathing, and in the most severe cases, anaphylaxis. A 2010 study published by The Journal of the American Medical Association showed that nearly a third of Americans think they have a food allergy, whether or not they have the actual immune system response to the culprit food – could this be a measure of how many of us have food intolerances?
The next natural question is WHY? How can something so basic as the food we eat be causing some of us extreme discomfort, pain and in some cases, the risk of death? Apparently basic does not necessarily mean simple. There currently is no definitive research that proves the cause of this dramatic increase in food allergies in the US. But there are a few theories, many that draw on the theme that food allergies are increasing only in developed countries and in modern times. (Please note that I am NOT a doctor – I have just tried to summarize below the information out there that has been produced by medical professionals)
1) The Hygiene Hypothesis – the idea that modern hygiene, with its antibiotics, vaccinations and cleanly lifestyles, has disrupted the normal development of our immune systems. Our immune systems have been shielded from having to fight off many of the germs and minor infections that would normally help them become stronger. This is the “boy in the bubble” theory.
2) Pesticides and genetically modified foods – A recent study by the American College of Allergy, Asthma & Immunology indicates that people exposed to higher levels of certain germ- and weed-killing chemicals may be more likely to develop food allergies. There are also theories that genetically modified soy may lead to increased soy allergies due to the change in the protein structure of the soybean. The consumption of genetically modified foods may damage our digestive tracts such that it creates a malfunction in the way our food gets absorbed.
Contrary to popular belief, wheat is currently not genetically modified in the US. It is, however, hybridized, meaning scientists breed wheat crops to reinforce particular characteristics that might lead to higher yields. The theory is that these changes in the structure of wheat have contributed to the rise of gluten sensitivity.
3) Form of food – different forms of the same food appear to be more likely to provoke an allergic response, for example roasting peanuts rather than boiling them makes them much more likely to cause an allergic reaction. Also, many people with milk or egg allergy can tolerate baked forms of these foods.
4) Lack of Vitamin D – people are spending more and more time indoors and therefore not getting enough exposure to sunlight. An Australian study by the Murdoch Children’s Research Institute found that children deficient in vitamin D are three times more likely to have a food allergy. They are also more likely to have multiple food allergies. The study says that Vitamin D is integral to the development of a healthy immune system in early life, especially in helping the gut to develop a healthy defense system.
5) Increased awareness and reporting – heightened awareness among doctors, parents, teachers and the general public about the symptoms and potential consequences of food allergies may contribute the reason we are meeting more people with food allergies. Also, with the trend towards eating healthier, people are being more conscious of what they put in their bodies and how it makes them feel. What people may have written off before as just normal discomfort that comes with eating now may be setting off alarms of something being wrong.
These seem to be the most prevalent theories out there about why food allergies are increasing, in particular the Hygiene Hypothesis seems to be the most popular theory. However I would like to stress that these are just theories, and while some medical research has been done on the cause of increasing food allergies, none of the research is definitive, and some studies contradict others. One other theory that I have is also that as a society our levels of stress and speediness have been increasing, and from personal experience, I know this triggers my digestive problems. While this may not be creating food allergies, it may contribute to symptoms of food allergies and intolerances being triggered more frequently now than before….something to think about.
Sources: http://fooddrugallergy.ucla.edu/body.cfm?id=40, http://www.annallergy.org/article/S1081-1206(12)00671-0/abstract, http://www.foodallergy.org/facts-and-stats, http://www.abc.net.au/health/features/stories/2013/03/07/3710140.htm, http://www.webmd.com/allergies/features/food-allergy-myths, http://www.medicaldaily.com/pesticide-exposure-linked-rising-rate-food-allergies-among-us-children-246533, http://celiacdisease.about.com/od/celiacdiseasefaqs/f/Genetically-Modified-Wheat.htm