Comparison of the non-haem iron content of UK foods between 1980 and 2000

Certain popular press reports have claimed that, in recent years, we are faced with a"depleted mineral content" of foods 8 an idea that was instigated from a published comparison in 2003 of values in food composition tables of the UK between 1940 and 1991. This idea has been readily criticised because improved analytical techniques of recent years have provided greater specificity in food-mineral analysis, which would most likely explain the differences in values found for the same foods in old and new food composition tables. However some support for this idea has come from other publications, and there are reasons why a reported decline in the mineral content of our diet is credible including changes to agricultural practices, the environment and food preparation (especially fortification practices). Using stored acid digests from 2002, we analysed the iron content of over 150 different, widely eaten, non-meat containing foods of the UK diet which, together, would account for above 70% of typical dietary iron intakes. We compared these results to published values from the 1980s. We found no evidence for the "depletion of iron" from plant based foods between the early 1980s and 2002. We cannot, of course, address how this may have changed in preceding years. However, since many of the agricultural, environmental and societal effects that have been claimed to affect food-mineral levels have been most pronounced in the past 20-30 years we suspect that reports claiming "mineral depletion of foods" during the previous fifty years were misled by a lack of specificity in food-mineral analysis prior to the 1960s. What our results did, however, again emphasise is the issue of "overage" when it comes to fortification of certain foods- especially cereals- with iron. Whether such over-fortification could have any long term consequences needs to be addressed.