Revised Study: Discussion
13.1 Thesis Summary
This thesis reports two studies that aimed to provide primary health care professionals with strategies to detect and offer effective evidenced based dietary treatment o f iron deficiency anaemia in young children. The objectives o f the first study were to identify any statistical associations between dietary habits, lifestyle variables and having a haemoglobin concentration <11.0g/dl and use this information to construct a non-invasive screening test for children aged 1.5-2.0 years. This would offer an unique alternative to population screening by universal blood sampling. It would also be logical to assume that parents would be more likely to take up the offer o f screening if the first stage o f screening involved a non-invasive test. Equally it is possible that parents are more likely to give permission for a second stage confirmatory blood test if it could be demonstrated their child was, on the basis o f the initial screening, likely to be anaemic. Regularly consuming milk at certain times o f day, age, having siblings and infrequent consumption o f fish were independently predictive o f increased odds o f suffering from anaemia. The different variables and combinations o f variables were unable to predict which children had anaemia sufficiently well to achieve the objective o f the screening test. That is, to reduce the numbers o f children undergoing invasive blood sampling while correctly identifying as many cases o f anaemia as possible. Furthermore, the test did not meet any o f the WHO criteria for a test used in a screening programme. The study concluded that non-invasive screening for IDA was not possible in this particular sample o f children and acknowledged that the sample may not be representative o f the wider population. Further work should examine ways to prevent IDA through primary prevention as the UK National Screening Committee recently advised there is insufficient evidence to recommend screening for IDA in children and emphasised primary prevention through good nutritional advice.
The second study measured the effects o f a drink o f cow ’s milk on non-haem bioavailability from meat based meals in children aged 1.0-1.4 years. The hypothesis was that cow ’s milk, which is rich in calcium, would depress the bioavailability o f
non-haem iron in test meals when compared with water. Calcium is the component o f milk thought to inhibit iron absorption although it is unclear whether its influence on iron bioavailability in adult subjects is as great as once thought. There are data on this subject in adults and infants, but very little on children over the age o f one year. At this age children are commonly consuming less iron fortified baby milks and foods and more cow ’s milk and family foods, which are low in iron and there is an
increased risk on anaemia in the second year. It would desirable to know if
consumption o f cow ’s milk compromises iron bioavailability from iron rich meals, as if it does, then advice can be given which optimises iron absorption. This has important clinical and public health nutrition implications. It is unfortunate that the study results had to be rejected because o f practical problems with the collection and preparation o f blood samples for analysis. It was therefore not possible to draw any conclusions about the effects o f cow ’s milk/calcium.
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