食品中钙的强化水平上限研究

目的探讨确定食品中微量营养素强化上限水平的方法;以钙为例,提出食品中钙的强化水平上限建议值。方法基于风险评估基本原则,利用2002年中国居民营养与健康状况调查数据,探讨应用强化水平上限计算模型,按不同经济发展水平、年龄、性别分层分析,得出不同经济发展水平下不同年龄及性别人群的食品中钙强化水平上限,将其中的最低值作为强化水平上限的初步建议值。结果大城市、一类农村及中小城市各年龄组居民食品中钙强化水平上限(MSFL)均低于全人群相应年龄组水平。一类农村18岁以上年龄组的MSFL是相应年龄组的最低值,2～7岁、11～18岁的MSFL的最低值来自大城市。各年龄组中,18～50岁年龄组的食品中钙强化水平上限最低,为262mg/1000kJ。结论通过模型计算结果与食品强化标准某些指标值的比较分析,认为该模型可用于提出有UL值的一类营养素的强化水平上限建议值。     

The economics of food fortification

This paper summarizes some of the literature on the cost effectiveness and cost benefit of food fortification with selected micronutrients most relevant for developing countries. Micronutrients covered include iron, iodine, vitamin A, and zinc. The main focus is on commercial fortification, although home fortification and biofortification are mentioned. Fortification with iron, vitamin A, and zinc averts significant numbers of infant and child deaths and is a very attractive preventive health-care intervention. Fortification with iron, iodine, and potentially zinc provides significant economic benefits and the low unit cost of food fortification ensures large benefit:cost ratios, with effects via cognition being very important for iron and iodine. Fortification will not reach all individuals and is most attractive as an investment where there is a convenient food vehicle, where processing is more centralized, and where either the deficiency is widespread or the adverse effects are very costly even though only a small group is affected.     

风险分析在食品强化管理中的应用

目的为完善我国食品强化政策法规,修订食品营养强化剂标准提供参考和依据。方法研究风险分析在国际及国外一些国家食品强化管理中的应用状况,按照风险分析的3个组成部分分别阐述食品强化管理中风险评估、风险管理和风险交流的特征及关键因素。结果营养素风险评估需同时考虑改善营养不足及防止营养过量,应根据营养素安全范围间距划分风险等级,进行分类管理。制定食品强化法规标准时,不应局限于针对单一营养素的评价,还要评估食品强化对膳食及疾病模式的影响。结论鉴于我国居民营养状况、膳食结构十分复杂,建议根据国情按照风险分析方法调整和完善食品强化政策和标准,指导食品工业界的研发,提高消费者的营养认知水平。     

Public health aspects of food fortification: a question of balance

Micronutrient malnutrition is widespread throughout the world, with important health and economic consequences. Tools to address this situation include food fortification, supplementation and dietary diversification, each having different and complementary roles. Fortification (mandatory and voluntary) has been practised over several decades in Western countries as well as in developing countries. Iodised salt was introduced in the USA in 1924 to reduce severe I deficiency. In 1938 voluntary enrichment of flours and breads with niacin and Fe was initiated to reduce the incidence of pellagra and Fe-deficiency anaemia respectively. Micronutrient intakes in European countries appear to be generally adequate for most nutrients. However, a number of population subgroups are at higher risk of suboptimal intakes (below the lower reference nutrient intake) for some micronutrients, e.g. folate, Fe, Zn and Ca in children, adolescents and young women. Dietary surveys indicate that fortified foods play a role in mitigating such risks for several important nutrients. The number of foods suited to fortification are considerably limited by several factors, including technological properties (notably moisture, pH and O2 permeability), leading to unacceptable taste and appearance, as well as cost and consumer expectations. In countries in which voluntary fortification is widely practised micronutrient intakes are considerably below tolerable upper intake levels. Concerns about safety are addressed in relation to the potentially increased level or proportion of fortified foods (e.g. following potential EU legislation), for nutrients with relatively low tolerable upper intake levels and where the potential benefit and risks are in different subpopulations (e.g. folic acid). Recent models for assessing these issues are discussed.     

The potential of encapsulated iron compounds in food fortification: a review

Iron (Fe) encapsulation has the potential to help overcome several major challenges in Fe fortification of foods. It may decrease unwanted sensory changes in fortified products and reduce interactions of Fe with food components that lower Fe bioavailability. However, the effect of encapsulation per se on Fe bioavailability is a concern. Rat studies comparing encapsulated ferrous sulfate, ferric ammonium citrate, and ferrous fumarate to non-encapsulated compounds indicate that a ratio of capsule:substrate of > or = 60:40 may decrease the relative bioavailability (RBV) of the Fe by approximately 20%. At a ratio of capsule:substrate of < or = 50:50, the RBV of encapsulated ferrous sulfate appears to be similar to ferrous sulfate. Even minor changes in capsule composition may influence Fe bioavailability. Encapsulated ferrous fumarate given with ascorbic acid as a complementary food supplement and encapsulated ferrous sulfate fortified into salt have been shown to be efficacious in anemic children. For salt fortification, further refinements in Fe capsule design are needed to increase resistance to moisture and abrasion, while maintaining bioavailability. Studies evaluating the potential efficacy of encapsulated Fe in staple cereals (wheat and maize flours) are needed. A potential barrier to use of encapsulated forms of Fe in staple food fortification is the relatively low melting point of the capsules, which may cause unwanted sensory changes during food preparation. Research and development efforts to improve the quality of coatings and their resistance to high temperatures are ongoing. Process costs for encapsulation can be high, and unless they can be reduced, may limit applications. Further research is needed to determine which encapsulation technologies are most effective in ensuring iron bioavailability from encapsulated compounds.     

Effect of food fortification with iron on childhood anemia: a review study

A systematic review was conducted to identify studies assessing the effect of food fortification with iron on childhood anemia. The MEDLINE, LILACS, and PubMed databases and WHO and PAHO sites were searched with no time limitation, including articles published in Portuguese, English, or Spanish, using the following key words and their combination: food fortification, iron, effectiveness, efficacy, anemia, flour, staple foods, interventions, and children. Of 21 studies reviewed, only one failed to report a positive, favorable effect of iron fortification, indicating the possibility of publication bias. The studies showed important methodological limitations. The two studies with the best methodological scores showed opposite results, highlighting the need for larger trials with better planning to explore this hypothesis.     

Preliminary evidence shows that folic acid fortification of the food supply is associated with higher methotrexate dosing in patients with rheumatoid arthritis

BACKGROUND: Fortification of the diet with folate has been used in the United States since 1997 to prevent neural tube defects in newborn babies. However, an increase in dietary folate intake could theoretically reduce the effectiveness of the anti-folate medication, methotrexate (MTX) in treating rheumatoid arthritis (RA) and other inflammatory diseases. OBJECTIVE: To investigate whether dietary fortification with folic acid interferes with MTX function in patients with RA. METHODS: We computed MTX dose per patient per year for the years 1988 to 1999 and plotted these against time, comparing the overall mean MTX dose before and after 1997, when dietary fortification with folic acid was instituted in the USA. Thirty-six subjects met eligibility criteria. RESULTS: Mean annual MTX dose was stable between 1988 and 1996 (12.4 +/- 4.0mg), but then rose linearly from 1997 to 1999 (16.6 +/- 5.1 mg, p < 0.001). CONCLUSIONS: This preliminary study suggests that folic acid supplementation may contribute to higher MTX dosing in patients with RA.     

Appropriate use of calcium antagonists in hypertension

The paradigm for treating hypertension has shifted: Tighter control is the goal and a multidrug regimen is often the means, especially in high-risk patients. Although renin-angiotensin blockers are now the key components of such regimens, calcium antagonists can play an important role as well, given their demonstrated efficacy in controlling blood pressure.     

Effectiveness of food fortification in the United States: the case of pellagra

OBJECTIVES: We evaluated the possible role of niacin fortification of the US food supply and other concurrent influences in eliminating the nutritional deficiency disease pellagra. METHODS: We traced chronological changes in pellagra mortality and morbidity and compared them with the development of federal regulations, state laws, and other national activities pertaining to the fortification of cereal-grain products with niacin and other B vitamins. We also compared these changes with other concurrent changes that would have affected pellagra mortality or morbidity. RESULTS: The results show the difficulty of evaluating the effectiveness of a single public health initiative such as food fortification without controlled experimental trials. Nonetheless, the results provide support for the belief that food fortification played a significant role in the elimination of pellagra in the United States. CONCLUSIONS: Food fortification that is designed to restore amounts of nutrients lost through grain milling was an effective tool in preventing pellagra, a classical nutritional deficiency disease, during the 1930s and 1940s, when food availability and variety were considerably less than are currently found in the United States.     

成本-效益分析法在食物铁强化项目中的应用现状

食物铁强化已经被越来越多的国家作为预防和控制铁缺乏和缺铁性贫血的主要策略。本文就各国食物铁强化项目的成本-效益分析报告进行了综述。目前成本-效益分析的运用范围和影响日益加剧,但是成本-效益方法广泛应用于食物铁强化项目尚待进一步的研究。     

Effect of food fortification on folic acid intake in the United States

BACKGROUND: The addition of folic acid to all enriched cereal-grain foods, mandated by the Food and Drug Administration (FDA), was initiated in January 1998. Although this program was designed such that typical folate intakes would be increased by approximately 100 micro g/d and that the risk of intakes > 1000 micro g/d (the FDA's safe upper limit of daily intake) would be minimal, its actual effect on folate intake has yet to be determined. OBJECTIVE: The objective was to estimate the effect of folic acid fortification on the amount of folate consumed by persons in the United States. DESIGN: Linear regression analysis of data from published studies was used to determine the relation between a chronic folic acid dose and the resulting increase in steady state concentrations of folate in plasma or serum. Using this regression equation and reverse prediction, we quantified the increase in folic acid intake from fortification required to achieve the increase in plasma or serum folate observed in published studies. RESULTS: The increase in circulating folate concentration was linearly related to folic acid intake over the range of 100-1000 micro g/d (r = 0.984, P < 0.0001). Predicted increases in folic acid intake from fortified food ranged from 215 to 240 micro g/d. CONCLUSIONS: Typical intakes of folic acid from fortified foods are more than twice the level originally predicted. The effect of this much higher level of fortification must be carefully assessed, especially before calls for higher levels of fortification are considered.     

National food fortification: a dialogue with reference to Asia: balanced advocacy

The vulnerability of large segments of Asia's population to micronutrient deficiency is more a consequence of cultural evolution and demography than of economic inequities. We evolved in a hunter-gatherer lifestyle with vigorous energy expenditure, wide dietary variety and a nutrient-dense diet (meat, viscera), and wound up 10,000 years ago as agriculturalists cultivating cereal and tuber crops for 70% of our dietary calories. Obtaining rice, maize and wheat is less energy intensive than needed for hunters' fare, while grains are distinctly less rich in available vitamins and minerals. Recurrent infectious episodes, transmitted in crowded societies, further deplete micronutrient nutriture. A fast-track option to address historically unprecedented life conditions includes chemical- or bio-fortification of ubiquitous condiments or widely consumed staples. With little or no change in habitual eating individuals will consume recommended micronutrient intakes and uptakes. Generous intakes of nutrients such as vitamin A and zinc counteract the adverse environmental effects on quality of life and survival in poverty situations. One size may not fit all, and over-consumption of certain micronutrients in heterogeneous societies is to be avoided. For the rice bowl to support the descendants of the caveman in the third millennium requires both imagination and technological ingenuity.     

Position of the American Dietetic Association: food fortification and dietary supplements

Wise food choices provide the necessary foundation for optimal nutrition. Science has not fully identified the specific chemical components that account for the benefits of healthy eating patterns. Selection of a variety of foods, using tools such as the USDA/HHS Dietary Guidelines for Americans and the USD A Food Guide Pyramid, is the best way to provide a desirable balance, without excessive intakes of macronutrients, micronutrients and other beneficial components of foods. Nevertheless, for certain nutrients and some individuals, fortification, supplementation, or both may also be desirable. Nutrient intakes from all these sources should be considered in dietary assessments, planning and recommendations. The recommendations of the National Academy of Sciences' Food and Nutrition Board provide a sound scientific basis for vitamin and mineral intakes. Intakes exceeding those recommendations have no demonstrated benefit for the normal, healthy population. Dietetics professionals should base recommendations for use of fortified foods or supplements on individualized assessment and sound scientific evidence of efficacy and safety. It is the position of the American Dietetic Association that the best nutritional strategy for promoting optimal health and reducing the risk of chronic disease is to wisely choose a wide variety of foods. Additional vitamins and minerals from fortified foods and/or supplements can help some people meet their nutritional needs as specified by science-based nutrition standards such as the Dietary Reference Intakes (DRI) J Am Diet Assoc. 2001; 101:115–125     

Economic evaluation of folic acid food fortification in The Netherlands

BACKGROUND: Folic acid intake before and during pregnancy reduces neural tube defects (NTD). Therefore, several countries have enriched bulk food with folic acid resulting in a 26-48% decrease in the prevalence of NTDs. In 2000, the Dutch Health Council advised against folic acid enrichment based on literature research; yet formal cost-effectiveness information was absent. We designed our study to estimate cost-effectiveness of folic acid food fortification in the Netherlands. METHOD: Prevalence of NTD at birth, life-time costs of care, and folic acid fortification costs were estimated using Dutch registrations, Dutch guidelines for costing, (inter)national literature and expert opinions. Both net cost per discounted life year gained and net cost per discounted quality adjusted life year (QALY) gained were estimated for the base case and sensitivity analyses. RESULTS: In the base case and most sensitivity analyses, folic acid enrichment was estimated to be cost-saving. Bulk food fortification with folic acid remains cost-effective as long as enrichment costs do not exceed euro5.5 million (threshold at euro20 000 per QALY). CONCLUSION: Our model suggests that folic acid fortification of bulk food to prevent cases of NTD in newborns might be a cost-saving intervention in the Netherlands. Additionally, besides the evidence that folic acid reduces the number of NTDs, there are indications that folic acid is associated with the prevention of other birth defects, cardiovascular diseases and cancer. Our model did not yet include these possibly beneficial effects.