MRC Human Nutrition Research, Elsie Widdowson Laboratory, Fulbourn Road, Cambridge CB1 9NL, UK.
Br J Nutr. 2012 Dec 28;108(12):2221-8. doi: 10.1017/S0007114512000360. Epub 2012 Mar 1.
In the UK contemporary estimates of dietary Fe intakes rely upon food Fe content data from the 1980s or before. Moreover, there has been speculation that the natural Fe content of foods has fallen over time, predominantly due to changes in agricultural practices. Therefore, we re-analysed common plant-based foods of the UK diet for their Fe content (the '2000s analyses') and compared the values with the most recent published values (the '1980s analyses') and the much older published values (the '1930s analyses'), the latter two being from different editions of the McCance and Widdowson food tables. Overall, there was remarkable consistency between analytical data for foods spanning the 70 years. There was a marginal, but significant, apparent decrease in natural food Fe content from the 1930s to 1980s/2000s. Whether this represents a true difference or is analytical error between the eras is unclear and how it could translate into differences in intake requires clarification. However, fortificant Fe levels (and fortificant Fe intake based upon linked national data) did appear to have increased between the 1980s and 2000s, and deserve further attention in light of recent potential concerns over the long-term safety and effectiveness of fortificant Fe. In conclusion, the overall Fe content of plant-based foods is largely consistent between the 1930s and 2000s, with a fall in natural dietary Fe content negated or even surpassed by a rise in fortificant Fe but for which the long-term effects are uncertain.
在英国，目前对膳食铁摄入量的估计主要依赖于 20 世纪 80 年代或更早时期的食物铁含量数据。此外，人们推测随着时间的推移，食物中的天然铁含量已经下降，这主要是由于农业实践的变化。因此，我们重新分析了英国饮食中常见的植物性食物的铁含量（“2000 年分析”），并将这些值与最近发表的值（“1980 年分析”）和更早发表的值（“1930 年分析”）进行了比较，后两者来自 McCance 和 Widdowson 食物表的不同版本。总的来说，跨越 70 年的食物分析数据之间存在显著的一致性。从 1930 年代到 1980 年代/2000 年代，天然食物铁含量略有但显著下降。这是否代表真正的差异，还是两个时代之间的分析误差尚不清楚，它如何转化为摄入量的差异也需要澄清。然而，强化铁水平（以及基于相关国家数据的强化铁摄入量）似乎在 1980 年代和 2000 年代之间有所增加，鉴于最近对强化铁的长期安全性和有效性的潜在担忧，这一点值得进一步关注。总之，植物性食物的铁含量在 1930 年代和 2000 年代之间基本一致，天然饮食铁含量的下降被强化铁的上升所抵消，甚至超过，但长期影响尚不确定。
