• [Show abstract] [Hide abstract]
    ABSTRACT: A consensus has been reached that the development of allergic disorders is strongly influenced by early life exposures. An overview of several prenatal and early life factors that have been investigated for their associations with development of childhood allergy is presented. Delivery mode, the gut microbiome, vitamin D, folate, breastfeeding, pets, antibiotics, environmental tobacco smoke, and airborne traffic pollutants are discussed. Although many studies suggest an effect, overall, no risk factors clearly increase or reduce the risk of allergic outcomes. Copyright © 2015 Elsevier Inc. All rights reserved.
    Immunology and Allergy Clinics of North America 02/2015; 35(1):1-17. DOI:10.1016/j.iac.2014.09.002 · 2.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Findings from experimental studies and animal models led to the hypothesis that folic acid supplementation during pregnancy confers an increased risk of asthma. This review provides a critical examination of current experimental and epidemiologic evidence of a causal association between folate status and asthma. In industrialized nations, the prevalence of asthma was rising before widespread fortification of foodstuff with folic acid or folate supplementation before or during pregnancy, thus suggesting that changes in folate status are an unlikely explanation for "the asthma epidemic". Consistent with this ecologic observation, evidence from human studies does not support moderate or strong effects of folate status on asthma. Given known protective effects against neural tube and cardiac defects, there is no reason to alter current recommendations for folic acid supplementation during conception or pregnancy based on findings for folate and asthma. While we believe that there are inadequate data to exclude a weak effect of maternal folate status on asthma or asthma symptoms, such effect could be examined within the context of very large (and ongoing) birth cohort studies. At this time, there is no justification for funding new studies of folate and asthma.
    American Journal of Respiratory and Critical Care Medicine 05/2013; 188(1). DOI:10.1164/rccm.201302-0317PP · 11.99 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: After a brief period of stabilization, recent data have shown that the prevalence of asthma and allergic diseases continues to increase. Atopic diseases are major public health problems resulting in significant disability and resource use globally. Although environmental factors influence the development of atopic disease, dietary changes might partially explain the high burden of atopic disease. Potential mechanisms through which diet is suspected to effect asthma and allergy susceptibility are through epigenetic changes, including DNA methylation. Dietary methyl donors are important in the one-carbon metabolic pathway that is essential for DNA methylation. Findings from both observational studies and interventional trials of dietary methyl donor supplementation on the development and treatment of asthma and allergy have produced mixed results. Although issues related to the differences in study design partially explain the heterogeneous results, 2 other issues have been largely overlooked in these studies. First, these nutrients affect one of many pathways and occur in many of the same foods. Second, it is now becoming clear that the human intestinal microbiome is involved in the metabolism and production of the B vitamins and other methyl donor nutrients. Future studies will need to account for both the interrelationships between these nutrients and the effects of the microbiome.
    The Journal of allergy and clinical immunology 12/2013; 133(5). DOI:10.1016/j.jaci.2013.10.039 · 11.25 Impact Factor