Transtorno do espectro autista e a suplementação por ácido fólico antes e durante a gestação

RESUMO Objetivo Elucidar se a suplementação com ácido fólico pouco antes da concepção e/ou durante a gestação pode estar realmente atrelado ao desenvolvimento do transtorno do espectro autista (TEA). Metódos Foi realizada uma revisão de literatura em base de dados, nos idiomas português e inglês, durante o período de novembro de 2017 até abril de 2018, com ênfase nas publicações mais recentes. Resultados Do total de 174 artigos, 87 compuseram este trabalho. Pesquisas apontam que o aumento dos casos de TEA se deve ao fato de que mais fatores genéticos estejam implicados na etiopatogênese neural. No entanto, a grande maioria dos artigos ressalta com maior precisão que há mais efeitos benéficos do uso de ácido fólico antes da concepção e durante a gestação na prevenção do TEA, assim como de outras anormalidades relacionadas aos defeitos do tubo neural. Conclusão Quando se analisa o risco-benefício da suplementação com ácido fólico nas doses recomendadas, 0,4 a 0,8 mg/dia, conclui-se que os benefícios sobrepujam os possíveis riscos de desenvolver o TEA.

Folic acid deficiency declined substantially after introduction of the mandatory fortification programme in Queensland, Australia: a secondary health data analysis

OBJECTIVE

To investigate the prevalence of folic acid deficiency in Queensland-wide data of routine laboratory measurements, especially in high-risk sub-populations.

DESIGN

Secondary health data analysis.

SETTING

Analysis of routine folic acid tests conducted by Pathology Queensland (AUSLAB).

PARTICIPANTS

Female and male persons aged 0-117 years with routine folic acid testing between 1 January 2004 and 31 December 2015. If repeat tests on the same person were conducted, only the initial test was analysed (n 291 908).

RESULTS

Overall the prevalence of folic acid deficiency declined from 7·5 % before (2004-2008) to 1·1 % after mandatory folic acid fortification (2010-2015; P < 0·001) reflecting a relative reduction of 85 %. Levels of erythrocyte folate increased significantly from a median (interquartile range) of 820 (580-1180) nmol/l in 2008 before fortification to 1020 (780-1350) nmol/l in 2010 (P < 0·001) after fortification. The prevalence of folic acid deficiency in the Indigenous population (14 792 samples) declined by 93 % (17·4 v. 1·3 %; P < 0·001); and by 84 % in non-Indigenous residents (7·0 v. 1·1 %; P < 0·001). In a logistic regression model the observed decrease of folic acid deficiency between 2008 and 2010 was found independent of gender, age and ethnicity (ORcrude = 0·20; 95 % CI 0·18, 0·23; P < 0·001; ORadjusted = 0·21; 95 % CI 0·18, 0·23; P < 0·001).

CONCLUSIONS

While voluntary folic acid fortification, introduced in 1995, failed especially in high-risk subgroups, the 2009 mandatory folic acid fortification programme coincided with a substantial decrease of folic acid deficiency in the entire population.

Low proportions of folic acid deficiency after introduction of mandatory folic acid fortification in remote areas of northern Queensland, Australia: a secondary health data analysis

Background: Australia implemented mandatory folic acid fortification of bread-making flour in 2009. Objective: To assess the impact of folic acid fortification in remote vs. regional urban areas and Indigenous vs. non-Indigenous populations in northern Queensland. Methods: Routinely collected data on folic acid measurements in remote areas and two regional urban centres in northern Queensland between 2004 and 2015 were analysed (n = 13,929) dichotomously (folic deficient vs. non-deficient). Results: Overall prevalence of folic acid deficiency was 3.2% (235/7282) in urban centres compared with 7.2% (480/6647) in remote areas (p < 0.001), and 9.3% (393/4240) in the Indigenous population compared with 3.2% (273/8451) in the non-Indigenous population (p < 0.001). Prevalence of folic acid deficiency dropped from 12.2% (n = 481) in 2004-2008 to 1.5% (n = 126) in 2010-2015 (p < 0.001). This translates into a relative risk reduction (RRR) of 88%. RRR was 79% (7.2% vs. 1.5%) in urban centres, 91% (17.3% vs. 1.5%) in remote areas, 92% (20.5% vs. 1.6%) in the Indigenous population and 80% (7.4% vs. 1.5%) in the non-Indigenous population (p < 0.001 for all). Conclusions: Substantial declines of folic acid deficiency to low and comparable proportions in former high-risk populations indicate that mandatory folic acid fortification of flour has had a population-wide benefit in northern Queensland.

Communicating the benefits of population health interventions: The health effects can be on par with those of medication

How can we communicate to the public that population level health interventions are effective at improving health? Perhaps the most familiar "currency" of effect is that which can be brought about via medication. Comparisons of effect sizes may be effective ways of communicating the benefits of population health interventions if they are seen and understood in the same way that medications are. We developed a series of comparisons to communicate benefits of population health interventions in terms of similar gains to be obtained from statins, metformin and antihypertensive medications for prevention of cardiovascular events, type 2 diabetes, obesity and hypertension. A purposive search identified evidence of population health intervention-related benefits. This evidence ranged from meta-analyses of RCTs to that from observational cohort studies. Population health interventions included implementation of national smoke free legislation, enhanced neighbourhood walkability, increased opportunities for active travel and protection of urban green space. In some cases, the benefits of population health interventions were found to be equivalent to, or even outweighed those of the medications to which they were compared. For example, RCT-based evidence suggested that exercise taken with a view of a green space was associated with 12 mmHg and 6 mmHg reductions in systolic and diastolic blood pressure, respectively, which was at least on par with the reductions associated with antihypertensive medications. Future work will test the effectiveness of these comparisons for increasing the familiarity, credibility and acceptability of population health interventions and, in particular, examine the importance of communicating putative mechanisms and potential co-benefits.

[The effect of folic acid fortification on the reduction of neural tube defects]

Neural tube defects are congenital malformations that occur during initial fetal development, leading to anencephaly and spina bifida; folic acid deficiency is the most important risk factor identified to date. Brazil has one of the world's highest neural tube defect rates. Food consumption surveys among pregnant Brazilian women showed a high rate of inadequate folic acid intake (< 0.6 mg/day). In 2004, the National Health Surveillance Agency (ANVISA) mandated the fortification of corn meal and wheat flour with folic acid (0.15 mg/100g). The National Family Budget Survey estimated the average amount of bread/flour products available in households as 106.1g/day (contributing with 0.16 mg folic acid/day). However, while in the South of the country the supply was 144 g/day, in the North and Central West it barely reached 70 g/day. Folic acid food fortification is mandatory in some 40 countries, but only four have assessed this strategy. The existing studies have all shown a significant impact, ranging from 19 to 78%. Folic acid fortification is an undeniably important intervention for primary prevention, and neural tube defects can now be considered a preventable epidemic.

An examination of income-related disparities in the nutritional quality of food selections among Canadian households from 1986–2001

Socio-economic disparities in nutrition have been documented in numerous countries, and have been linked to health inequalities. Social and economic policy changes occurring over the last several years have resulted in growing levels of income inequality in many countries. However, the extent to which these temporal changes have affected nutrition disparities is largely unknown. Our research examined income-related disparities in the nutritional quality of food selections among Canadian households from 1986 to 2001. Data from the 1986, 1992, 1996 and 2001 Family Food Expenditure surveys were pooled together (n=35048). The relationships between household income and the nutritional quality of food purchases (considering nutrients both as absolute amounts and adjusted for energy, and total energy density) were estimated using general linear models, including tests of significance for differences across the survey years. Results revealed significant positive relationships between income and most nutrients, which persisted over time, and for some nutrients grew stronger. One exception was folate, where the positive relationship between income and folate (independent of energy) was no longer apparent in 2001; this could be attributed to the mandatory fortification of some cereal grain products with folic acid, which came into effect in 1998, resulting in greater availability of folate from grain products. There was also a significant negative relationship between income and total energy density (ratio of food energy to food weight), which persisted across the survey years. At a time of growing income inequality and worsening problems of poverty, food policy makers need to pay attention to the potential for policy interventions to exacerbate or improve nutrition disparities.

The repeating history of objections to the fortification of bread and alcohol: from iron filings to folic acid

The fortification of staple foods has eliminated many deficiency diseases. Despite this, "tampering" with people's food always provokes opposition, much of it from health professionals. Opposition is often based on self-interest, tunnel vision and theory rather than research. A historical perspective of the patterns of objections to fortification and its outcomes may help resolve the anxieties and opposing ethical positions of advocates and opponents of fortification.