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.
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.
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References
Food and Nutrition Board. Dietary Reference Intakes for thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, pantothenic acid, biotin and choline. Washington, DC: National Academy Press, 1998.
Chalmers B, Dzakpasu S, Heaman M, Kaczorowski J. The Canadian maternity experiences survey: An overview of findings. J Obstet Gynaecol Can 2008;30(3):217–28.
Canada Gazette Part II. SOR/98-550. Regulatory impact analysis statement. In: Bureau of Food Regulatory IaIA, Health Canada (Ed.) 1998;3029–33.
De Wals P, Tairou F, Van Allen MI, Uh SH, Lowry RB, Sibbald B, et al. Reduction in neural-tube defects after folic acid fortification in Canada. N Engl J Med 2007;357(2):135–42.
Ray JG, Vermeulen MJ, Boss SC, Cole DEC. Declining rate of folate insufficiency among adults following increased folic acid food fortification in Canada. Can J Public Health 2002;93(4):249–53.
Liu S, West R, Randell E, Longerich L, O’Connor KS, Scott H, et al. A comprehensive evaluation of food fortification with folic acid for the primary prevention of neural tube defects. BMC Pregnancy Childbirth 2004;4(1):20.
Oakley GP, Jr. Folic acid fortification: Time for a concentrated effort. CMAJ 2002;167(8):848.
Society of Obstetricians and Gynaecologists of Canada & Motherisk. Pre-conceptional vitamin/folic acid supplementation 2007: The use of folic acid in combination with a multivitamin supplement for the prevention of neural tube defects and other congenital anomalies. J Obstet Gynaecol Can 2007;201:1003–13.
Cole BF, Baron JA, Sandler RS, Haile RW, Ahnen DJ, Bresalier RS, et al. Folic acid for the prevention of colorectal adenomas: A randomized clinical trial. JAMA 2007;297(21):2351–59.
Mason JB, Dickstein A, Jacques PF, Haggarty P, Selhub J, Dallal G, et al. A temporal association between folic acid fortification and an increase in colorec-tal cancer rates may be illuminating important biological principles: A hypothesis. Cancer Epidemiol Biomarkers Prev 2007;16(7):1325–29.
Troen AM, Mitchell B, Sorensen B, Wener MH, Johnston A, Wood B, et al. Unmetabolized folic acid in plasma is associated with reduced natural killer cell cytotoxicity among postmenopausal women. J Nutr 2006;136(1):189–94.
Morris MS, Jacques PF, Rosenberg IH, Selhub J. Folate and vitamin B-12 status in relation to anemia, macrocytosis, and cognitive impairment in older Americans in the age of folic acid fortification. Am J Clin Nutr 2007;85(1):193–200.
Yajnik CS, Deshpande SS, Jackson AA, Refsum H, Rao S, Fisher DJ, et al. Vitamin B(12) and folate concentrations during pregnancy and insulin resistance in the offspring: The Pune Maternal Nutrition Study. Diabetologia 2008;51(1):29–38.
Rader JI, Weaver CM, Angyal G. Total folate in enriched cereal-grain products in the United States following fortification. Food Chemistry 2000;70:275–89.
Johnston KE, Tamura T. Folate content in commercial white and whole wheat sandwich breads. J Agric Food Chem 2004;52(20):6338–40.
Statistics Canada. Food Expenditure Survey 2001. 2005. Available online at: http://www40.statcan.ca/l01/cst01/famil27a.htm (Accessed October 30, 2006).
Health Canada. Nutrition Labelling: Get the Facts! 2008. Available online at: http://www.hc-sc.gc.ca/fn-an/label-etiquet/nutrition/educat/te_ background-le_point-eng.php (Accessed May 20, 2008).
Canadian Food Inspection Agency. Section C — Contents of the Nutrition Facts Table. 2005. Available online at: http://www.inspection.gc.ca/english/fssa/labeti/nutrikit/sectce.shtml#tabc6 (Accessed May 20, 2008).
Health Canada. Canadian Nutrient File, 2007b. 2007. Available online at: http://www.hc-sc.gc.ca/fn-an/nutrition/fiche-nutri-data/index_e.html (Accessed December 15, 2007).
USDA Agricultural Research Service. USDA National Nutrient Database for Standard Reference, Release 19. Nutrient Data Laboratory Home Page. 2006. Available online at: http://www.ars.usda.gov/ba/bhnrc/ndl (Accessed July 10, 2007).
Tamura T, Mizuno Y, Johnston KE, Jacob RA. Food folate assay with protease, α-amylase, and folate conjugase treatments. J Agric Food Chem 1997;45:135–39.
Wilson SD, Horne DW. High-performance liquid chromatographic determination of the distribution of naturally occurring folic acid derivatives in rat liver. Anal Biochem 1984;142(2):529–35.
Hyun TH, Tamura T. Trienzyme extraction in combination with microbio-logic assay in food folate analysis: An updated review. Exp Biol Med (Maywood) 2005;230(7):444–54.
Molloy AM, Scott JM. Microbiological assay for serum, plasma, and red cell folate using cryopreserved, microtiter plate method. Methods Enzymol 1997;281:43–53.
Quinlivan E P, Gregory JF, III. The impact of food fortification on folic acid intake in Canada. Can J Public Health 2003;94(2):154.
Ray JG, Vermeulen MJ, Boss SC, Cole DE. Increased red cell folate concentrations in women of reproductive age after Canadian folic acid food fortification. Epidemiology 2002;13(2):238–40.
Health Canada. Addition of vitamins and minerals to foods: Health Canada’s proposed policy and implementation plans. 2005. Available online at: http://www.hc-sc.gc.ca/fn-an/nutrition/vitamin/fortification_final_doc_1-eng.php (Accessed July 13, 2008).
Smith AD, Kim YI, Refsum H. Is folic acid good for everyone? Am J Clin Nutr 2008;87(3):517–33.
Sherwood KL, Houghton LA, Tarasuk V, O’Connor DL. One-third of pregnant and lactating women may not be meeting their folate requirements from diet alone based on mandated levels of folic acid fortification. J Nutr 2006;136:2820–26.
Health Canada. Eating Well with Canada’s Food Guide. Available online at: http://www.hc-sc.gc.ca/fn-an/food-guide-aliment/index-eng.php (Accessed June 15, 2008).
Public Health Agency of Canada. Why all women who could become pregnant should be taking Folic Acid. Available online at: http://www.phac-aspc.gc.ca/fa-af/index-eng.php (Accessed July 14, 2008).
Faulkner H, Hussein A, Foran M, Szijarto L. A survey of vitamin A and D contents of fortified fluid milk in Ontario. J Dairy Sci 2000;83(6):1210–16.
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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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Shakur, Y.A., Rogenstein, C., Hartman-Craven, B. et al. How Much Folate Is in Canadian Fortified Products 10 Years after Mandated Fortification?. Can J Public Health 100, 281–284 (2009). https://doi.org/10.1007/BF03403947
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DOI: https://doi.org/10.1007/BF03403947