Abstract
Objective: In 1998, the Canadian government mandated folic acid fortification of white flour and enriched grain products to lower the prevalence of neural tube defects. There is now growing concern over the potential harmful effects of too much folic acid on some segments of the population. Given that the actual amount of folate in Canadian foods is unknown, the objective of this study was to measure the folate content in selected fortified foods.
Methods: Using data from the 2001 Food Expenditure Survey and the ACNielsen Company, 95 of the most commonly purchased folic acid-fortified foods in Canada were identified. Folate concentrations in these foods were determined using tri-enzyme digestion followed by microbiological assay. Analyzed values were compared to those in the Canadian Nutrient File (2007b, CNF) and to label values.
Results: The analyzed folate content of foods was, on average, 151% ± 63 of the CNF values. Analyzed values as a percent of CNF values ranged from 116% in the “rolls and buns” category to 188% in “ready-to-eat cereals”. Analyzed values were higher than label values for “breads”, “rolls and buns” and “ready-to-eat cereals” (141%, 118% and 237%, respectively [p<0.05]).
Conclusions: Ten years after folic acid fortification of the food supply, neither the CNF nor label values accurately reflect actual amounts of folate in foods. Further, overage differences by food category hinder the development of future strategies designed to strike the right balance between health benefits and risks; monitoring of fortified foods for their nutrient content is required.
Keywords: Folic acid, Canada, food supply, fortified foods
Résumé
Objectifs: En 1998, le gouvernement du Canada a exigé l’ajout d’acide folique à la farine blanche et aux produits de grains enrichis afin de réduire la prévalence d’anomalies du tube neural. Une nouvelle inquiétude prend de plus en de place concernant les effets nocifs d’une dose trop forte d’acide folique dans certains segments de la population. Étant donné que l’on ignore la quantité actuelle d’acide folique ajouté aux aliments canadiens, cette étude vise à mesurer le contenu d’acide folique à une sélection d’aliments enrichis.
Méthodes: Nous avons utilisé les données de l’Enquête sur les dépenses alimentaires des familles 2001 et de la société ACNielsen afin de déterminer 95 des aliments enrichis d’acide folique les plus vendus au Canada. Nous avons établi les concertations d’acide folique de ces aliments en utilisant la digestion tri-enzymes, suivie d’une épreuve microbiologique. Nous avons ensuite comparé les valeurs analysées à celles du Fichier canadien sur les éléments nutritifs (2007b, FCEN) et aux valeurs nutritionnelles affichées sur l’étiquette.
Résultats: Le contenu d’acide folique des aliments se situe en moyenne à 151 % ± 63 des valeurs du FCEN. Les valeurs analysées en tant que pourcentage des valeurs du FCEN varient de 116 % dans la catégorie «petits pains» à 188 % dans les «céréales prêtes à manger». Les valeurs analysées sont plus élevées que les valeurs affichées sur les étiquettes des «pains», «petits pains» et «céréales prêtes à manger» (141 %, 118 % et 237 % respectivement [p<0,05]).
Conclusions: Dix ans après avoir enrichi les aliments d’acide folique, ni les valeurs du FCEN ni celles des étiquettes ne reflètent précisément les quantités réelles d’acide folique que contiennent les aliments. En outre, les différences globales par catégorie d’aliment peuvent entraver l’élaboration de stratégies futures conçues pour trouver le bon équilibre entre les avantages et les risques pour la santé; il faut donc surveiller le contenu en nutriments des aliments enrichis.
Mots clés: acide folique, Canada, approvisionnement alimentaire, aliments enrichis
Footnotes
Acknowledgements of sources of support: The authors acknowledge the support of the Natural Sciences and Engineering Research Council of Canada. Yaseer Shakur was supported through a studentship, in part, by the Ontario Student Opportunity Trust Fund - Hospital for Sick Children Foundation Student Scholarship Program. Carly Rogenstein was supported in part through a Canada Graduate Scholarship Masters Award from the Canadian Institutes of Health Research.
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