In The Allergy Epidemic: A Mystery of Modern Life, Dr Susan Prescott, an internationally renowned specialist in childhood allergy and immunology, takes us on a journey into the allergy epidemic.
As the number of those affected by allergies escalates around the globe, Dr Prescott gives explanations about this mysterious disease.
As both an allergy specialist working in a busy children's hospital and as a cutting edge researcher Susan Prescott is perfectly placed to explore how and why we are experiencing an epidemic rise in allergic diseases as well as the practical side of dealing with these potentially life-threatening conditions. Drawing on the latest research, The Allergy Epidemic provides clear, no-nonsense explanations that Dr Prescott is renowned for with her clients.
Just how big is this problem? The World Allergy Organisation (WAO) now estimates that up to 40% of the world's population now suffer from one or more allergic disease (such as asthma, eczema, food allergy and allergic rhinitis). This translates to many hundreds of millions, making this a global public health problem of major proportions. Australia has one of the highest allergy rates in the world and annual health spend in this area is over $8 billion. In just 10 years there has been a 5-fold rise in serious (anaphylactic) food allergies in preschoolers. As these younger generations reach adulthood, the burden of allergic diseases is expected to increase even more.
Why is this happening? Allergy is part of an even bigger problem of a global rise in virtually all immune diseases. We see this pattern in every region of the world as they adopt the modern lifestyle. This is very clear evidence that our immune systems are highly vulnerable to modern environmental changes.
What is going wrong with the immune system? The immune system is a complex and intricate network which achieves a fine balance between 'protection' from threats (such as infection) and 'tolerance' to harmless things. Allergies and other immune diseases occur when the 'balance' is disrupted, so that we are more likely to make misdirected responses to harmless things. In essence, we have disturbed the natural balance of our environment and we are now experiencing the impact on our own health.
What are the environmental factors driving this? Our modern lifestyles differ in so many ways from traditional environments that it is hard to pin the blame on any one factor. Increasing 'hygiene' has been a lead candidate, but many other factors are known to have immune effects, such as modern environmental pollutants, reduced sunlight exposure (more screen-time and indoor activities lower vitamin D levels) and modern dietary patterns (with less fresh fruits, vegetables, fibre, and omega 3 fats) which may promote inflammation. It is likely that a combination of these modern lifestyle changes is promoting many modern diseases, not just allergy.
Why is allergy increasing so rapidly in very young infants? The latest Australian data indicate that around 10% of 1 year old infants now have food allergy and even more have other symptoms such as eczema. The fact that first symptoms can occur within weeks of life, and that changes in the immune 'balance' can be detected at birth is clear evidence that the effects of environmental change begin very early in life, even in pregnancy.
What is epigenetics? Epigenetics is a new frontier of medicine that explains how gene expression is controlled, and how environmental exposures can change epigenetic control of gene expression to alter the risk of disease. Harnessing this 'plasticity' may also hold the key to reversing the problem through prevention strategies in early life.
What are the latest treatments and can allergy be cured? There have been significant advances in the treatment of all allergic diseases and the latest approaches are all outlined in The Allergy Epidemic. (start at pp112). In some patients immunotherapy (treatment of disease by inducing, enhancing, or suppressing an immune response) provides a solution to allergic disease, and there is intensive research to make this a safe option in a wider range of allergic conditions.
Where is the research heading? Better understanding of the molecular processes in allergy is aimed at providing more effective targeted treatments for people with established allergic disease. But the ultimate goal is to reverse the epidemic and prevent allergies in the first place. To do this we need to define environmental strategies that restore an optimal 'immune balance' during early development. It is hoped that reducing early environmental risk factors may ultimately reduce the risk of many modern diseases.
Dr Susan Prescott is a Paediatric Allergist and Immunologist at Princess Margaret Hospital for Children in Perth. She is internationally recognised for her research in the area of allergy and early immune development.
The Allergy Epidemic
Author: Dr Susan Prescott
Question: What inspired you to write The Allergy Epidemic?
Dr. Susan Prescott: We have had an increase in allergies with each generation and everybody I meet (whether in the clinic or on the street) are so full of questions including: Why is it happening? and What is going on with the immune system. We are busy dealing with the practicalities everyday that we don't have time to explain the bigger questions.
Firstly, I really wanted to inform and educate people but on the other hand I really wanted to raise awareness of the scale and the impact of allergic illnesses because I think that it is fair to say that large sections of the community and our profession have been a bit slow to take this seriously.
I also wanted to engage people on this subject and inspire them to get behind the cause because we need to a lot more research.
Question: Why did you decide to donate all the profits from The Allergy Epidemic?
Dr. Susan Prescott: I am donating all my proceeds to allergy research, just by buying a copy readers are making a direct contribution. I want to promote awareness of the allergy problem because it is huge and at the same time I hoped to put a positive spin on it and really leave people with optimism and a sense of hope for discovery. We are on the way to try and solve the allergy epidemic. One important aspect is to make people aware of the issue, in the first place and with the current crisis there has never been a better time to share with people what we do know about allergies.
Question: Why are we seeing allergies escalate, worldwide?
Dr. Susan Prescott: The first point to make is that it is part of a bigger problem, allergy is only one immune disease but it is the most common. We are seeing a rise in all immune diseases including insulin diabetes, inflammatory bowel disease and the rheumatic conditions. This rise is telling us that our immune systems are vulnerable to the environment and changes that have occurred in the last 40 to 50 years, this is clearly environmental. It cannot be explained by our genes but the environment may be influencing how our genes are expressed, in other words making us more prone to making the wrong immune decisions.
In terms of environmental factors there are so many differences between our modern environment and a traditional environment; which means it's hard to blame one factor, it will be a combination. The leading suspects include hygiene (our relationship with bacteria has changed and we may not be getting the same kick start to the immune system) secondly we have very different dietary patterns, we have much less fresh fruit and vegetables, fibre and all of the protective things such as omega-3 which means we may be more inflammation prone, from that.
Thirdly, the modern pollutants and fourthly the changes in our behaviour including that we are more likely to be indoors and out of natural light including the concern that our vitamin D levels are dropping. The big picture is understanding what the optimal environment is and how we can restore the balance and that will have flow on affects for allergies and other modern diseases that have risen during the same period, which shows they may have the same risk factors.
Question: Can allergies be cured?
Dr. Susan Prescott: The only curative strategy available at the moment is immunotherapy which includes allergy shots, drops and tablets that retrain the immune system to no longer react to allergens and reduce the severity of asthma and hayfever, the best examples of immunotherapy are to dust mites and pollen. What we are trying to look at is rolling out immunotherapy so that it can be used widely in a broader range of conditions because at the moment it is not appropriate for everybody.
In food allergy immunotherapy is quite experimental and dangerous and at the moment it is not used as a curative strategy for food allergy except for in research studies. In research studies there is evidence that if you start with tiny doses of the food and build up a reasonable serve size you may be able to repress the response and switch it off permanently; this is a very dangerous procedure that is reserved for research purposes, only. These studies are showing some promise although there are still concerns as to how effective it is and how we can improve its safety.
Question: How can parents help prevent their children from developing allergies?
Dr. Susan Prescott: We would love to be able to prevent allergies occurring and there has been some research promise especially with the diet is for a mother's omega-3 status during pregnancy. We know that things like probiotics including dietary fibre and soluble fibre may have anti-inflammatory affects and reduce the risk of allergies. The probiotics are under research because so far it is a little bit vague as some probiotics seem to have an effect and others don't. Smoking is also something we strongly recommend people don't do, that is a definitely risk factor.
Interview by Brooke Hunter