Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Plenty of evidence on mandatory folate fortification

Plenty of evidence on mandatory folate fortification Telethon Institute for Child Health Research, University of Western Australia Gina Ambrosini, Siobhan Hickling, Elizabeth Geelhoed School of Population Health, University of Western Australia Leon Flicker School of Medicine and Pharmacology, University of Western Australia We read with interest the Point of View from Dr Mark Lawrence (Aust N Z J Public Health 2005;29(4):328-30), addressing mandatory fortification of food with folate in Australia. Dr Lawrence calls for ongoing national nutrition surveys and monitoring and evaluation of policy interventions to inform decision-making for this and future public health nutrition policy. With this we concur. However, Dr Lawrence also states that, as mandatory fortification has not been implemented in Australia and New Zealand, the associated risks and benefits cannot be predicted with certainty. Thus, it is unclear whether there would ever be a situation where this dilemma could be resolved for Dr Lawrence – there will be no data in Australia on risks and benefits of mandatory fortification because there is no mandatory fortification, but mandatory fortification should not be implemented if the risks and benefits have not been assessed. Dr Lawrence states that governments have done very little to support the implementation of non-mandatory folate fortification policy options, and we agree. However, there are both Australian and overseas data to show that periconceptional supplement use is taken up by no more than half of the target population, even in places where there has been considerable health promotion. Furthermore, there are inequities between those who do and who do not take folic acid supplements.1 Voluntary fortification has been in place in Australia since 1996. While there is some evidence from Western Australia that there are no inequities in consumption of voluntarily fortified foods in non-Indigenous women,2 the gap is widening between neural tube defect (NTD) rates in Indigenous compared with non-Indigenous infants, as there has been no fall in NTDs in Indigenous infants, but a 30% fall in NTDs in nonIndigenous infants.3 It is because of these inequities that mandatory fortification has such appeal. Dr Lawrence states that “it is known that folate’s protective effect is conferred optimally when it is consumed in pharmacological ‘doses’”. This is not so. The maximal protective effect calculated from a meta-analysis of the best available evidence is 70%,4 with doses varying from 0.4mg – 4mg in the trials reviewed. However, there is observational evidence of up to 80% reduction in NTDs 2006 VOL. 30 NO. 1 with 0.4mg folic acid supplements in China5 and 78% reduction in NTDs in Newfoundland since folate fortification was mandated in Canada in 1996 at a level of 0.15-0.20 mg per 100 gm flour, cornmeal and pasta, resulting in an average dietary intake of folic acid due to fortification of 70µg daily.6 None of these levels is a pharmacological dose – indeed, 0.4mg folate is the recommended daily dietary intake for periconceptional and pregnancy consumption in Australia – and yet they have had the effect of lowering NTD rates by ~70%, considered to be the maximal protective effect based on data from randomised controlled trials. Dr Lawrence states that one of the ‘peculiar’ circumstances associated with translating scientific evidence about folate-NTD into policy is the low prevalence of NTD in Australia and New Zealand. However, similar population-wide programs have been instituted to prevent conditions that are orders of magnitude less common. We vaccinate the whole population against a mild exanthematous infection to prevent women becoming infected in pregnancy so that their fetuses do not develop congenital rubella syndrome – less than half as common as NTD before vaccination was instituted, even at the peak of rubella epidemics in Australia.7 Similarly, in 2003, the Federal Government committed many millions of dollars to population vaccination against meningoccal C infection, which affected approximately 190 people a year in Australia and with considerably less mortality (7-10%) and morbidity than NTD, which has at least a 50% mortality and close to 100% morbidity in survivors. Dr Lawrence raises two potential risks of elevated folate intake. The first, an increased risk of multiple births, he himself counters with several pieces of evidence: demonstration of uncontrolled confounding as a reason for the association observed in one of the studies; no increase in multiple births in the large China study; and no evidence of an increase in twins in the United States since mandatory fortification has been introduced there. What further evidence is needed? The second relates to exposing the population to novel levels of synthetic folic acid and the inability to predict the negative effects. Examples discussed include interaction with folate antagonists and anticonvulsants, although evidence for this is based on high levels of folate supplementation, rather than more modest levels associated with fortification. The concern over masking the anaemia of vitamin B12 deficiency is also raised and, again, no evidence of this occurring has been found in either the US or Canada since fortification was implemented there.6 We contend that most public health policy making is undertaken in the face of scientific uncertainty and that most public health initiatives are applied to all or most of the population for the benefit of many fewer. The challenge is in balancing the risks and benefits. Can we afford to delay the implementation of this public health strategy that has clearly identified benefits and is without adverse effects being reported from countries with much larger populations than ours where mandatory fortification has been in place for several years? We join with Dr Lawrence in calling for appropriate monitoring and evaluation of policy interventions generally. We also join with AUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH Letters risks and benefits cannot be predicted with certainty, it is advocating a circular argument of never having evidence to act and never acting to obtain evidence. Unfortunately, a key word as well as the context to this statement were omitted by the authors and hence changed the meaning of this important point. What the article states is that mandatory folate fortification has not been implemented. The sentence then explains that this approach would create a precedent food fortification policy. Mandatory food fortification has been implemented in Australia and New Zealand for many years, e.g. in 1991 thiamin fortification of bread-making flour began in Australia. Then, as now, policy makers could not anticipate with certainty the potential risks and benefits of a mandatory fortification policy. In the absence of evaluative evidence, policy principles for guiding food fortification were, and are, available.1 As the article comments, evidence of a population-wide nutrient deficiency would meet these principles. Whereas there was evidence of population-wide suboptimal thiamin reserves before the mandatory thiamin fortification policy decision was made,2 there is a lack of evidence of folate deficiency among the population. In this context a decision of mandatory folate fortification policy would be made without the ‘compass’ of policy principles to guide policy makers and lead into uncertain risk and benefit territory. Bower et al. challenge the effectiveness of health promotion interventions to achieve folate intake targets and assert that persisting with such approaches will contribute to health inequities. It is debateable whether there have been sufficiently resourced health promotion interventions to enable their potential to be realised. Nevertheless, and as the article states, mandatory fortification would be the most effective and equitable policy to improve the target group’s exposure to increased amounts of folic acid. The uncertainty is that it is the very effectiveness and equitable nature of this form of delivery that also raises concerns about its broader public health impact. As a non-discriminatory intervention it will increase the exposure of not just the target group, but also all children, men and older women to raised amounts of synthetic folic acid for many years. The use of the term ‘pharmacological’ dose is disputed. Yet, as Bower et al. comment, the evidence of the protective effect of folic acid was derived from a meta-analysis of epidemiological studies using amounts of folic acid ranging up to 10 times the Australian and New Zealand recommended dietary intake for the target group. Elsewhere, modelling to specify the dose-response relationship between folic acid and NTDs has indicated that 5mg folic acid per day is required before pregnancy and during the first trimester for optimal risk reduction.3 The respondents’ argument that in certain countries modest levels of mandatory folate fortification have substantially lowered NTD rates is understood. One uncertainty is that in the United States (US) the rate reduction has been less substantial, leading some to claim that optimal NTD reduction will require a four-fold increase in the present US level of folate fortification.4 Unfortunately, a debate about terminology distracts from the critical issue in this section of the article. The term pharmacological was used against the 2006 VOL. 30 NO. 1 the Health Ministers of Australia and New Zealand in calling for adequate monitoring and evaluation of mandatory fortification as an essential component of its introduction. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Australian and New Zealand Journal of Public Health Wiley

Plenty of evidence on mandatory folate fortification

Download PDF
2 pages

Loading next page...
 
/lp/wiley/plenty-of-evidence-on-mandatory-folate-fortification-uFQX4aVkOC

References (9)

Publisher
Wiley
Copyright
Copyright © 2006 Wiley Subscription Services, Inc., A Wiley Company
ISSN
1326-0200
eISSN
1753-6405
DOI
10.1111/j.1467-842X.2006.tb00091.x
Publisher site
See Article on Publisher Site

Abstract

Telethon Institute for Child Health Research, University of Western Australia Gina Ambrosini, Siobhan Hickling, Elizabeth Geelhoed School of Population Health, University of Western Australia Leon Flicker School of Medicine and Pharmacology, University of Western Australia We read with interest the Point of View from Dr Mark Lawrence (Aust N Z J Public Health 2005;29(4):328-30), addressing mandatory fortification of food with folate in Australia. Dr Lawrence calls for ongoing national nutrition surveys and monitoring and evaluation of policy interventions to inform decision-making for this and future public health nutrition policy. With this we concur. However, Dr Lawrence also states that, as mandatory fortification has not been implemented in Australia and New Zealand, the associated risks and benefits cannot be predicted with certainty. Thus, it is unclear whether there would ever be a situation where this dilemma could be resolved for Dr Lawrence – there will be no data in Australia on risks and benefits of mandatory fortification because there is no mandatory fortification, but mandatory fortification should not be implemented if the risks and benefits have not been assessed. Dr Lawrence states that governments have done very little to support the implementation of non-mandatory folate fortification policy options, and we agree. However, there are both Australian and overseas data to show that periconceptional supplement use is taken up by no more than half of the target population, even in places where there has been considerable health promotion. Furthermore, there are inequities between those who do and who do not take folic acid supplements.1 Voluntary fortification has been in place in Australia since 1996. While there is some evidence from Western Australia that there are no inequities in consumption of voluntarily fortified foods in non-Indigenous women,2 the gap is widening between neural tube defect (NTD) rates in Indigenous compared with non-Indigenous infants, as there has been no fall in NTDs in Indigenous infants, but a 30% fall in NTDs in nonIndigenous infants.3 It is because of these inequities that mandatory fortification has such appeal. Dr Lawrence states that “it is known that folate’s protective effect is conferred optimally when it is consumed in pharmacological ‘doses’”. This is not so. The maximal protective effect calculated from a meta-analysis of the best available evidence is 70%,4 with doses varying from 0.4mg – 4mg in the trials reviewed. However, there is observational evidence of up to 80% reduction in NTDs 2006 VOL. 30 NO. 1 with 0.4mg folic acid supplements in China5 and 78% reduction in NTDs in Newfoundland since folate fortification was mandated in Canada in 1996 at a level of 0.15-0.20 mg per 100 gm flour, cornmeal and pasta, resulting in an average dietary intake of folic acid due to fortification of 70µg daily.6 None of these levels is a pharmacological dose – indeed, 0.4mg folate is the recommended daily dietary intake for periconceptional and pregnancy consumption in Australia – and yet they have had the effect of lowering NTD rates by ~70%, considered to be the maximal protective effect based on data from randomised controlled trials. Dr Lawrence states that one of the ‘peculiar’ circumstances associated with translating scientific evidence about folate-NTD into policy is the low prevalence of NTD in Australia and New Zealand. However, similar population-wide programs have been instituted to prevent conditions that are orders of magnitude less common. We vaccinate the whole population against a mild exanthematous infection to prevent women becoming infected in pregnancy so that their fetuses do not develop congenital rubella syndrome – less than half as common as NTD before vaccination was instituted, even at the peak of rubella epidemics in Australia.7 Similarly, in 2003, the Federal Government committed many millions of dollars to population vaccination against meningoccal C infection, which affected approximately 190 people a year in Australia and with considerably less mortality (7-10%) and morbidity than NTD, which has at least a 50% mortality and close to 100% morbidity in survivors. Dr Lawrence raises two potential risks of elevated folate intake. The first, an increased risk of multiple births, he himself counters with several pieces of evidence: demonstration of uncontrolled confounding as a reason for the association observed in one of the studies; no increase in multiple births in the large China study; and no evidence of an increase in twins in the United States since mandatory fortification has been introduced there. What further evidence is needed? The second relates to exposing the population to novel levels of synthetic folic acid and the inability to predict the negative effects. Examples discussed include interaction with folate antagonists and anticonvulsants, although evidence for this is based on high levels of folate supplementation, rather than more modest levels associated with fortification. The concern over masking the anaemia of vitamin B12 deficiency is also raised and, again, no evidence of this occurring has been found in either the US or Canada since fortification was implemented there.6 We contend that most public health policy making is undertaken in the face of scientific uncertainty and that most public health initiatives are applied to all or most of the population for the benefit of many fewer. The challenge is in balancing the risks and benefits. Can we afford to delay the implementation of this public health strategy that has clearly identified benefits and is without adverse effects being reported from countries with much larger populations than ours where mandatory fortification has been in place for several years? We join with Dr Lawrence in calling for appropriate monitoring and evaluation of policy interventions generally. We also join with AUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH Letters risks and benefits cannot be predicted with certainty, it is advocating a circular argument of never having evidence to act and never acting to obtain evidence. Unfortunately, a key word as well as the context to this statement were omitted by the authors and hence changed the meaning of this important point. What the article states is that mandatory folate fortification has not been implemented. The sentence then explains that this approach would create a precedent food fortification policy. Mandatory food fortification has been implemented in Australia and New Zealand for many years, e.g. in 1991 thiamin fortification of bread-making flour began in Australia. Then, as now, policy makers could not anticipate with certainty the potential risks and benefits of a mandatory fortification policy. In the absence of evaluative evidence, policy principles for guiding food fortification were, and are, available.1 As the article comments, evidence of a population-wide nutrient deficiency would meet these principles. Whereas there was evidence of population-wide suboptimal thiamin reserves before the mandatory thiamin fortification policy decision was made,2 there is a lack of evidence of folate deficiency among the population. In this context a decision of mandatory folate fortification policy would be made without the ‘compass’ of policy principles to guide policy makers and lead into uncertain risk and benefit territory. Bower et al. challenge the effectiveness of health promotion interventions to achieve folate intake targets and assert that persisting with such approaches will contribute to health inequities. It is debateable whether there have been sufficiently resourced health promotion interventions to enable their potential to be realised. Nevertheless, and as the article states, mandatory fortification would be the most effective and equitable policy to improve the target group’s exposure to increased amounts of folic acid. The uncertainty is that it is the very effectiveness and equitable nature of this form of delivery that also raises concerns about its broader public health impact. As a non-discriminatory intervention it will increase the exposure of not just the target group, but also all children, men and older women to raised amounts of synthetic folic acid for many years. The use of the term ‘pharmacological’ dose is disputed. Yet, as Bower et al. comment, the evidence of the protective effect of folic acid was derived from a meta-analysis of epidemiological studies using amounts of folic acid ranging up to 10 times the Australian and New Zealand recommended dietary intake for the target group. Elsewhere, modelling to specify the dose-response relationship between folic acid and NTDs has indicated that 5mg folic acid per day is required before pregnancy and during the first trimester for optimal risk reduction.3 The respondents’ argument that in certain countries modest levels of mandatory folate fortification have substantially lowered NTD rates is understood. One uncertainty is that in the United States (US) the rate reduction has been less substantial, leading some to claim that optimal NTD reduction will require a four-fold increase in the present US level of folate fortification.4 Unfortunately, a debate about terminology distracts from the critical issue in this section of the article. The term pharmacological was used against the 2006 VOL. 30 NO. 1 the Health Ministers of Australia and New Zealand in calling for adequate monitoring and evaluation of mandatory fortification as an essential component of its introduction.

Journal

Australian and New Zealand Journal of Public Health – Wiley

Published: Feb 1, 2006

There are no references for this article.