The challenge: Parents are often advised to limit their child’s exposure to things that can cause harm. Yet they are also warned against over-sanitizing their child’s environment because exposure to dirt and germs can help a child's immune system. What do scientists know about the developing immune system and the causes of allergies, asthma and chronic diseases like obesity, diabetes and cardiovascular diseases?
The response: The Canadian Healthy Infant Longitudinal Development (CHILD) Study, a birth cohort study of 3,500 Canadian children and their families, funded by AllerGen and the Canadian Institutes of Health Research, is identifying the early life exposures that affect a baby’s health and well-being down the road: breathing in traffic fumes during infancy can increase the risk of allergies; early introduction of potentially allergenic foods (eggs, peanut, milk) reduces the risk of developing allergies to these foods; consuming diet drinks in pregnancy may increase a baby’s risk of obesity; and consuming fruit while pregnant boosts a baby’s cognitive development.