The Hygiene Hypothesis explained

Over the last 50 years, there has been an alarming rise in the Western world in the prevalence of allergic disorders such as hay fever, atopic dermatitis (or eczema), and asthma. One theory regarding the reason behind this is in the “Hygiene Hypothesis”.

During the first year of life, a child’s immune system is being educated about how to defend itself against LIFETIME of pathogens. It is normal for a child to develop mild respiratory symptoms, as part of the immune system’s ‘training’. Exposure to common pathogens initiates this training in order to develop a healthy immune system which can differentiate ‘self’ from ‘non-self’.The “Hygiene Hypothesis” suggests that without this exposure, the immune system can become hypersensitive to many common allergens, predisposing the child to allergic disorders such as asthma, allergies, and eczema. Basically, excessive cleanliness in our environment may lead to faulty and inadequate immune system training due to lack of pathogenic stimuli. For example, evidence shows that children with more than two infections during the first year of life have less risk of developing allergic disorders by age five.

Who has the lowest incidence of atopy (asthma, allergies, eczema)?

• Children who are raised on farms (especially those who are exposed to the barnyard environment in utero)
• Children who minimise/ avoid the use of antibiotics early in life. Early antibiotic use has consistently been associated with asthma and allergy by 6 years of age.
• Children who drink unpasteurised milk
• Children who have larger numbers of older siblings
• Children who attend group day care at an earlier age
• Children who are exposed to pets

What do all these have in common? These little ones are exposed to a larger number of microbes!!As with everything, simply exposing your children to the great outdoors isn’t the ONLY way to ensure a healthy immune system. Adequate nutrition, a healthy diet during pregnancy, and a reduction of toxin exposure (before and after birth) can also go a long way towards ensuring your kids have healthy immune responses.I’ll leave you with a great quote I heard earlier this year… “Early management of the immune system is simply the most efficient and cost-effective approach in terms of reducing a lifetime of problems and healthcare costs”. How very true that is!References:Illi S et al 2001, ‘Early childhood infectious disease and the development of asthma up to school age: a birth cohort study’ BMJ, Feb 17; 332(7283): 390-5Bock K 2011, ‘The Epidemics of Childhood – Autism, ADHA, Asthma and Allergies’ Speaker at the 2011International Congress on Natural Medicine, Metagenics, June 11th-13th, Melbourne.Risnes KR, Belanger K, Murk W, Bracken MB 2011, ‘Antibiotic exposure by 6 months and asthma and allergy at 6 years: Findings in a cohort of 1,401 US children’ Am J Epidemiol. Feb 1;173(3):310-8