Exploration Of Exposures Associated With Bedding That Are Risks For Childhood Allergy And Asthma Symptoms
Funder
National Health and Medical Research Council
Funding Amount
$263,500.00
Summary
Asthma prevalence in Australia has doubled in the last 20 years, with 1 in 4 children now affected. House dust mites are probably the single most important allergen associated with asthma. The prevalence of mite allergy is linked to exposure, and such allergy when combined with high exposure, is a potent risk factor for asthma exacerbations. The current international advice for managing mite-allergic asthma, strongly advocates the use of bedding encasings as the best way to reduce exposure. Howe ....Asthma prevalence in Australia has doubled in the last 20 years, with 1 in 4 children now affected. House dust mites are probably the single most important allergen associated with asthma. The prevalence of mite allergy is linked to exposure, and such allergy when combined with high exposure, is a potent risk factor for asthma exacerbations. The current international advice for managing mite-allergic asthma, strongly advocates the use of bedding encasings as the best way to reduce exposure. However, three recent major trials using encasings and a meta-analysis of earlier trials all fail to show a clinical benefit. One of the applicants (ET) recently showed, using expertise in measuring personal exposure, that these encasings, as used, fail to significantly reduce aeroallergen exposure. By contrast, 3 recent Australian studies, involving the applicants, AK, ALP and NG showed that feather bedding compared to synthetic bedding, was strongly protective for asthma - the opposite of public advice. The suggested mechanisms involve reduced exposure to mite allergens, or altered exposure to bacterial endotoxin, but persuasive experimental support is lacking. We also propose a novel hypothesis that feather exposure may induce allergic 'tolerance'. Currently there is a lack of certainty about valid approaches to prevent asthma, and the Global Initiative for Asthma has described the need to understand mechanisms and improve interventions as urgent. This project is an ideal opportunity to combine the expertise of the CIA (ET) in measuring airborne exposures (mite, endotoxin, proteins) with that of the others who have expertise in children's asthma, and who are already involved in two large clinical trails involving different bedding and allergen avoidance. Our measurements of these bedding exposures and their clinical outcomes will provide, for the first time, a quantitative basis to refine public health allergen-based interventions to prevent and manage asthma.Read moreRead less
Allergic disease affects more than one in five Australian children. What foods a mother eats during pregnancy and breastfeeding, as well as when to introduce solid foods to babies, is thought to be critical in reducing the increasing burden of allergies in our Australian community. I hope to use this fellowship to discover what dietary factors put children at risk of developing a food allergy, and ways we can reduce that risk.
Immunomodulatory Effects Of Omega-3 Polyunsaturated Fatty Acids : Role In Allergy Prevention In Infancy
Funder
National Health and Medical Research Council
Funding Amount
$537,600.00
Summary
The dramatic increase in asthma and allergic disease over the last 20-30 years has highlighted the urgent need to identify associated environmental changes that may also be logical targets for disease prevention. Although this is likely to be multifactorial, one significant change during this period has been a progressive decline in the intake of dietary anti-inflammatory n-3 polyunsaturated fats (PUFA) in Western diets, with a corresponding increase in n-6 PUFA fatty acids. We recently showed f ....The dramatic increase in asthma and allergic disease over the last 20-30 years has highlighted the urgent need to identify associated environmental changes that may also be logical targets for disease prevention. Although this is likely to be multifactorial, one significant change during this period has been a progressive decline in the intake of dietary anti-inflammatory n-3 polyunsaturated fats (PUFA) in Western diets, with a corresponding increase in n-6 PUFA fatty acids. We recently showed for the first time that n-3 PUFA may have more significant effects in very early life before immune responses are fully established. We confirmed that maternal fish oil supplementation (n-40) resulted in significantly higher n-3 PUFA levels in newborns (compared to those with no supplements, n-43), and this was related to reduced immune responses to allergens (such as house dust mite, cat and egg). These observations suggest that n-3 PUFA can modify early immune development. Although this previous study was designed to assess immune outcomes (rather than clinical outcomes) we collected preliminary clinical data for the purposes of this application. We observed a consistent trend for less allergic symptoms and sensitisation in the supplementation group. These observations clearly warrant this proposed study to confirm these clinical effects, and to assess the mechanisms of action in considerably more detail. In this proposed study we will compare the effects of fish oil (n-165) or placebo (n-165) in early infancy (from 0-6 months of age). This much larger population will allow us to determine if increasing dietary n-3 PUFA is a way of reducing the chance of allergy in families where there is a high genetic risk. Approximately 40% of infants in Australia will go on to develop asthma or allergies. Strategies such as this that reduce the risk (even slightly) or the severity of disease expression could have enormous impact in this global context at relatively little cost.Read moreRead less