Allergy Awareness Week
Fact of the week: UK hospital admissions for food allergies have increased by 500% since 1990 (Gupta, 2007)
So what is an Allergy?
An allergy is a response from the body’s immune system to a normally harmless substances from foods, pollens to dust mites. Normally these substances are harmless to people but people who have an allergy towards them as their immune identifies them as a threat and gives and inappropriate response.
Allergies can be classed into two categories IgE mediated and non IgE mediated allergies. With IgE mediated allergies the immune system produces exaggerated amounts of a distinct class of antibodies known as IgE antibodies that are specific to the offending allergies.
These antibodies bind to cells called mast cells which become sensitised so they can react the next time the body comes in contact with the allergen.
When these mast cells come in contact with an allergen once they have been sensitized to it they can give identify it as an intruder or threat and produce histamine and other chemicals to combat the threat. These cells are normally found in areas of the body which come into contact with the outside environment such as the nose, mouth, throat, eyes, skin and stomach. You may have spotted these are the areas of the body you have symptoms when you suffer form an illness or cold.
An IgE mediated allergy can cause a wide spectrum of symptoms, some not to serious like a runny nose to much more serious such as breathing problems from the throat swelling, severe asthma and blood pressure drops. Severe allergic reactions are known as anaphylaxis which can be life threatening.
Non IgE meditated allergies are much less well understood and occur without the IgE antibody, it is thought that the reactions involve multiple cells reacting inappropriately to the allergen, sysmtoms are not always immediate as with IgE mediated and so much harder to identify and treat.
Allergies are increasing
An increase in allergies was initially seen in Europe and the USA however now it is occurring in most developed countries. There are a number of hypothesis as to why this is, perhaps more than one of these factors are contributing towards the increase;
The Hygiene Hypothesis
In developed countries we have developed ‘cleaner’ environments using cleaning agents and disinfectants. This change has reduced the natural variation in the types and quantity of germs our immune systems need for it to develop enough to recognise the genuine threats over non threatening allergens. To compare life in a developed country to a developing country shows many factors which could potentially lead to a very different environment. In developing countries there are usually large family sizes, more rural living, contact with livestock, lower antibiotic use, poorer sanitation. In a developed country you are more likely to be an only child, living in an affluent urban environment with good sanitation and higher use of antibiotics and more accessible medical services and treatments.
The food we eat
It is undeniable that our diets have changed beyond all recognition in the last 60 years. Evolution takes place over a very long period and so our bodies have evolved to live in a very different environment to where we live no and have a very different diet. Our diets tend to include more processed foods and less fruit and vegetables however we now have far broader range of foods available to us than our grandparents had, in your own lifetime you can probably see how things have changed and the choice available now but at the same time a huge jump in the amount of processed food.
Changes in how we are exposed to allergens
Many cosmetic products which simply did not exist 50 years ago contain ingredients derived from potentially allergenic food. It has been suggested exposing the body to potential allergens through skin creams may cause the development of allergy in people who are potentially at risk. The evidence is unclear for this as it is difficult to test.
The environment is also very different to what it was, there is evidence that pollutants can exacerbate existing airway allergy but it isn’t known if it can cause it. On the one had there are more potentially harmful man-made agents in the environment but there is also less exposure to germs as outlined with the Hygiene Hypothesis
Allergies in the Home
Click the image to go to the Allergy UK site and see which areas of the home can be hotspots for allergens.
We have a range of Allergy UK certified products which give you confidence that the product has been fully tested and certified as safe to use.