Preventing Allergies: New Recommendations and Thoughts

Food allergies are on the rise in developed countries. It has become a significant source of fear for parents, who know that sometimes the smallest exposure to an allergen could kill their children in a matter of minutes. It has become a challenge for schools, daycares, and other institutions who want to ensure a safe environment for all children without being overly restrictive about the foods other children can bring with them. The implications of food allergies range from inconvenience to death. Parents of infants and young children, especially in families with a history of food allergies, want to do everything they can to protect their children. There is a lot of fear when introducing common allergens to high-risk infants and some families have even been known to go and sit in the parking lot of the Children's Hospital while introducing nuts or other allergens for the first time (even though Pediatrician Dr. Daniel Flanders noted to me on twitter that "ironically, the first introduction doesn't illicit a reaction. Only happens with subsequent exposures.").

Because of the high and ever-increasing prevalance of food allergies in Canada (7% among the general population, and >10% of one-year olds), the Canadian Paediatric Society (CPS) considers allergy prevention a key health goal. As a result of ongoing research, guidelines for health care providers has been updated in a number of countries including the United States, Europe and Australia in the past few years. In December 2013, CPS issued a joint statement along with the Canadian Society of Allergy and Clinical Immunology on Dietary Exposures and Allergy Prevention in High-Risk Infants. Their new recommendations are as follows (emphasis mine):

    Do not restrict maternal diet during pregnancy or lactation. There is no evidence that avoiding milk, egg, peanut or other potential allergens during pregnancy helps to prevent allergy, while the risks of maternal undernutrition and potential harm to the infant may be significant. (Evidence II-2B)
    Breastfeed exclusively for the first six months of life. Whether breastfeeding prevents allergy as well as providing optimal infant nutrition and other manifest benefits is not known. The total duration of breastfeeding (at least six months) may be more protective than exclusive breastfeeding for six months. (Evidence II-2B)
    Choose a hydrolyzed cow’s milk-based formula, if necessary. For mothers who cannot or choose not to breastfeed, there is limited evidence that hydrolyzed cow’s milk formula has a preventive effect against atopic dermatitis compared with intact cow’s milk formula. Extensively hydrolyzed casein formula is likely to be more effective than partially hydrolyzed whey formula in preventing atopic dermatitis. Amino acid-based formula has not been studied for allergy prevention, and there is no role for soy formula in allergy prevention. It is unclear whether any infant formula has a protective effect for allergic conditions other than atopic dermatitis. (Evidence IB)
    Do not delay the introduction of any specific solid food beyond six months of age. Later introduction of peanut, fish or egg does not prevent, and may even increase, the risk of developing food allergy. (Evidence II-2B)
    More research is needed on the early introduction of specific foods to prevent allergy. Inducing tolerance by introducing solid foods at four to six months of age is currently under investigation and cannot be recommended at this time. The benefits of this approach need to be confirmed in a rigorous prospective trial. (Evidence II-2B)
    Current research on immunological responses appears to suggest that the regular ingestion of newly introduced foods (eg, several times per week and with a soft mashed consistency to prevent choking) is important to maintain tolerance. However, routine skin or specific IgE blood testing before a first ingestion is discouraged due to the high risk of potentially confusing false-positive results. (Evidence II-2B)

I bolded some of the items that were of particular interest to me or that seemed to be different from things I've read in the media, in baby or pregnancy books, or heard as advice being passed down from one mother to another.

I think these recommendations are an important part of our individual management of allergy risk within our own families. At the same time, CPS notes that ongoing research is of course needed on the topic.

But beyond the timing of the introduction of foods, I was interested in what some of the other potential causes are for the increase in allergies. Like many other issues we are facing in our society, there must be systemic issues that are contributing to the trend. So I asked Dr. Edmond Chan, the co-author of the statement on Dietary Exposures and Allergy Prevention in High-Risk Infants for his thoughts on a couple of questions.

Q: Do we know what is causing food allergy to increase?

A: The CPS position statement is focused only on one potential contributing cause, i.e.) dietary exposures during early infancy and their potential impact on development of food allergy.  The “cause” of the food allergy increase is based on a variety of genetic and environmental factors all coming together, rather than one single cause.  In addition to delayed versus early exposure to foods, other environmental factors likely include:  ability to manage eczematous skin, the hygiene hypothesis, and other possible factors (such as the role of probiotics, omega 3 fatty acids, vitamin D, etc).

Q: Do we know what makes food allergy more prevalent in some countries rather than others?

A: Studies suggest that food allergy is more prevalent in developed countries.  This aligns with the suspected causes listed above, as data suggests that developed countries are more likely to have the mix of environmental factors which promote development of food allergy:  i.e.) delayed introduction of foods, conditions which exacerbate eczematous skin, fewer germs to educate the immune system in a beneficial way, etc.

There is little that can be done about genes, but ongoing research, guidance and interventions on the other issues are particularly important in my mind. As an example, the "fewer germs" issue is one that gets raised in many other contexts as well. In addition to more allergies, there is also concern about the increased use of antibiotics (in humans and animals) and antibacterial products and the resulting increase in antibiotic resistence. On the NHS website in the UK, an article on food allergies references the rise in food allergies and notes:

    One theory is that the rise in cases is due to the changes in a typical child’s diet that has occurred over the last 30 to 40 years.

    Another theory is that children are increasingly growing up in "germ-free" environments. This means that their immune system may not receive sufficient early exposure to the germs it needs to develop properly. This is known as the hygiene hypothesis.

I've written before about how I'm more afraid of chemicals (in cleaning products) than germs and how my babies were healthy without Lysol (despite what the marketers of Lysol would like you to believe). I don't think that routine disinfecting is a good idea. I think it limits our children's exposure to the germs they need to be exposed to in order to develop healthy immune systems. But I wonder how we, as a society, can manage the combination of allergy risk and overdisinfecting risk? How do you ensure people who need to be exposed to germs are exposed to them while also limiting the exposure of those with developed allergies to allergens that are so dangerous to them?

I know that some of my smart readers have children with allergies and I know that many of them are also on the green/natural end of the spectrum. I'm interested in hearing from them and from all of you on the ways that we, as a society, can manage the very real risk of exposure to allergens for allergic children while also trying to prevent developing allergies in the population as a whole.




Courtesy:  http://www.phdinparenting.com/blog/2014/1/14/introducing-allergens-to-infants-and-preventing-allergies-ne.html

Food allergies are on the rise in developed countries. It has become a significant source of fear for parents, who know that sometimes the smallest exposure to an allergen could kill their children in a matter of minutes. It has become a challenge for schools, daycares, and other institutions who want to ensure a safe environment for all children without being overly restrictive about the foods other children can bring with them. The implications of food allergies range from inconvenience to death. Parents of infants and young children, especially in families with a history of food allergies, want to do everything they can to protect their children. There is a lot of fear when introducing common allergens to high-risk infants and some families have even been known to go and sit in the parking lot of the Children's Hospital while introducing nuts or other allergens for the first time (even though Pediatrician Dr. Daniel Flanders noted to me on twitter that "ironically, the first introduction doesn't illicit a reaction. Only happens with subsequent exposures.").

Because of the high and ever-increasing prevalance of food allergies in Canada (7% among the general population, and >10% of one-year olds), the Canadian Paediatric Society (CPS) considers allergy prevention a key health goal. As a result of ongoing research, guidelines for health care providers has been updated in a number of countries including the United States, Europe and Australia in the past few years. In December 2013, CPS issued a joint statement along with the Canadian Society of Allergy and Clinical Immunology on Dietary Exposures and Allergy Prevention in High-Risk Infants. Their new recommendations are as follows (emphasis mine):

• Do not restrict maternal diet during pregnancy or lactation. There is no evidence that avoiding milk, egg, peanut or other potential allergens during pregnancy helps to prevent allergy, while the risks of maternal undernutrition and potential harm to the infant may be significant. (Evidence II-2B)
• Breastfeed exclusively for the first six months of life. Whether breastfeeding prevents allergy as well as providing optimal infant nutrition and other manifest benefits is not known. The total duration of breastfeeding (at least six months) may be more protective than exclusive breastfeeding for six months. (Evidence II-2B)
• Choose a hydrolyzed cow’s milk-based formula, if necessary. For mothers who cannot or choose not to breastfeed, there is limited evidence that hydrolyzed cow’s milk formula has a preventive effect against atopic dermatitis compared with intact cow’s milk formula. Extensively hydrolyzed casein formula is likely to be more effective than partially hydrolyzed whey formula in preventing atopic dermatitis. Amino acid-based formula has not been studied for allergy prevention, and there is no role for soy formula in allergy prevention. It is unclear whether any infant formula has a protective effect for allergic conditions other than atopic dermatitis. (Evidence IB)
• Do not delay the introduction of any specific solid food beyond six months of age. Later introduction of peanut, fish or egg does not prevent, and may even increase, the risk of developing food allergy. (Evidence II-2B)
• More research is needed on the early introduction of specific foods to prevent allergy. Inducing tolerance by introducing solid foods at four to six months of age is currently under investigation and cannot be recommended at this time. The benefits of this approach need to be confirmed in a rigorous prospective trial. (Evidence II-2B)
• Current research on immunological responses appears to suggest that the regular ingestion of newly introduced foods (eg, several times per week and with a soft mashed consistency to prevent choking) is important to maintain tolerance. However, routine skin or specific IgE blood testing before a first ingestion is discouraged due to the high risk of potentially confusing false-positive results. (Evidence II-2B)

I bolded some of the items that were of particular interest to me or that seemed to be different from things I've read in the media, in baby or pregnancy books, or heard as advice being passed down from one mother to another.
I think these recommendations are an important part of our individual management of allergy risk within our own families. At the same time, CPS notes that ongoing research is of course needed on the topic.
But beyond the timing of the introduction of foods, I was interested in what some of the other potential causes are for the increase in allergies. Like many other issues we are facing in our society, there must be systemic issues that are contributing to the trend. So I asked Dr. Edmond Chan, the co-author of the statement on Dietary Exposures and Allergy Prevention in High-Risk Infants for his thoughts on a couple of questions.

Q: Do we know what is causing food allergy to increase? 

A: The CPS position statement is focused only on one potential contributing cause, i.e.) dietary exposures during early infancy and their potential impact on development of food allergy.  The “cause” of the food allergy increase is based on a variety of genetic and environmental factors all coming together, rather than one single cause.  In addition to delayed versus early exposure to foods, other environmental factors likely include:  ability to manage eczematous skin, the hygiene hypothesis, and other possible factors (such as the role of probiotics, omega 3 fatty acids, vitamin D, etc).

Q: Do we know what makes food allergy more prevalent in some countries rather than others? 

A: Studies suggest that food allergy is more prevalent in developed countries.  This aligns with the suspected causes listed above, as data suggests that developed countries are more likely to have the mix of environmental factors which promote development of food allergy:  i.e.) delayed introduction of foods, conditions which exacerbate eczematous skin, fewer germs to educate the immune system in a beneficial way, etc.

There is little that can be done about genes, but ongoing research, guidance and interventions on the other issues are particularly important in my mind. As an example, the "fewer germs" issue is one that gets raised in many other contexts as well. In addition to more allergies, there is also concern about the increased use of antibiotics (in humans and animals) and antibacterial products and the resulting increase in antibiotic resistence. On the NHS website in the UK, an article on food allergies references the rise in food allergies and notes:

One theory is that the rise in cases is due to the changes in a typical child’s diet that has occurred over the last 30 to 40 years.
Another theory is that children are increasingly growing up in "germ-free" environments. This means that their immune system may not receive sufficient early exposure to the germs it needs to develop properly. This is known as the hygiene hypothesis.

I've written before about how I'm more afraid of chemicals (in cleaning products) than germs and how my babies were healthy without Lysol (despite what the marketers of Lysol would like you to believe). I don't think that routine disinfecting is a good idea. I think it limits our children's exposure to the germs they need to be exposed to in order to develop healthy immune systems. But I wonder how we, as a society, can manage the combination of allergy risk and overdisinfecting risk? How do you ensure people who need to be exposed to germs are exposed to them while also limiting the exposure of those with developed allergies to allergens that are so dangerous to them?
I know that some of my smart readers have children with allergies and I know that many of them are also on the green/natural end of the spectrum. I'm interested in hearing from them and from all of you on the ways that we, as a society, can manage the very real risk of exposure to allergens for allergic children while also trying to prevent developing allergies in the population as a whole.
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