The present paper reports dietary habits of pregnant women in the Republic of Seychelles, a small island developing state and the location for a number of long-term observational epidemiological studies examining the effect of fish consumption on infant neurodevelopment (36,41)
. Mean (SD) weekly fish consumption was high at approximately 527 (327) g(42)
and therefore would be expected to contribute considerably to dietary intakes of micronutrients such as iodine, Se and Zn. Indeed, women meeting dietary recommendations for all of the aforementioned micronutrients had a significantly higher fish intake. In the group as a whole, however, comparison of micronutrient intakes (adjusted means) with UK EAR or RNI where appropriate indicated noticeable shortfalls. Dietary Fe requirements, for example, were not met by 80·6% of the population (based on UK EAR). The Institute of Medicine have concluded that Fe is the only nutrient in pregnancy for which diet alone cannot meet requirements(43)
. Supplements are routinely supplied during pregnancy in Seychelles but uptake appears sporadic at best(44)
. Although some dietary intakes observed in our study were low, the findings are comparable to those in populations in the UK, Mexico and South Africa(45–47)
Initial analysis of the current cohort suggested that iodine intakes did not meet recommendations in 62·9% of the study group (based on UK RNI). Low intakes of dietary iodine have also been observed in women of childbearing age in Europe and are approximately 50% of recommendations(48)
. This apparent shortfall in iodine intake is of concern as low iodine status in pregnancy has adverse implications for fetal neurodevelopment(49)
. However, intakes are likely to have been underestimated as the iodine content of some fish species consumed in Seychelles is unknown and therefore was unaccounted for in the dietary analysis. Subsequent analysis, using an assumed average iodine concentration per 100 g fish, suggested that 36·3% did not meet requirements. Dietary intakes of Se were adequate in 79·8% of the whole group (based on UK RNI). Although not the richest source of Se, bread had high habitual consumption that ensured this food group was the highest contributor to dietary Se, followed by fish. Adequate Se status might be important in high fish-eating populations given its possible role in counteracting the toxicity of methylmercury, which is also present in fish. Although Zn deficiency has been estimated to be as high as 25% in the world’s population(50)
, in our study group inadequate Zn intakes (based on UK EAR) were seen in only 8·4% of the population. However, after excluding under-reporters, the levels of apparent nutritional inadequacy decreased by 13·8%, 19·6% and 55·0% for Fe, iodine and Se, respectively, and the dietary recommendation for Zn intake of 5·5 mg/d was met by all subjects.
Since recommendations for choline intake were published, several studies have reported that choline intakes often do not meet recommendations in both pregnant(51)
and non-pregnant individuals(52)
. Currently no RNI or EAR has been defined for choline; however, in the USA an Adequate Intake (AI) for pregnant women of 450mg/d has been established. In our study group choline intake was 198mg/d. This intake is considerably lower than the AI, despite habitual consumption of eggs that in the current study supplied 33·4% of the choline intake. However, as with the assessment of dietary iodine intake, dietary choline intakes are likely to have been underestimated owing to the incompleteness of the dietary database.
When interpreting the results of the present survey, the biases associated with conducting dietary surveys must be acknowledged; most notably, under-reporting and the use of standard portion sizes to estimate weights of food consumed. In our study the lack of data on pre-pregnancy weight, combined with the use of an estimated PAL(53)
, will have influenced the determination of BMR and, subsequently, the calculated cut-off for under-reporting. Therefore, we might have underestimated under-reporting and it is not possible to state conclusively that subjects above the cut-off level determined for under-reporting were actually achieving their energy and/or nutrient requirements. It is also conceivable their levels of under-reporting could have been underestimated owing to reluctance among subjects to report foods accepted as inappropriate during pregnancy, such as alcohol. It is also impossible to state if some foods regarded as being ‘healthy’ were over-reported. Nevertheless, the levels of under-reporting observed are plausible based on one other study in pregnant women(54)
and within the range observed in other studies which used more objective measures to assess energy requirements (55,56)
. Consequently, we believe the findings are likely to be an accurate reflection of misreporting in this group.
In the absence of biochemical indices of micronutrient status, adequacy of micronutrient intakes was judged against UK dietary recommendations. To reduce the inaccuracies associated with estimating nutritional inadequacy, statistical methods were used to estimate the usual distribution of intakes based on the observed intakes. The variety of foods generally available for consumption in the Seychelles is limited compared with Western societies. This lack of variability may have reduced reporting errors and improved accuracy in assessment of nutrient intake. In addition, piloting and feasibility studies were undertaken in Seychelles prior to initiation of the current dietary survey(27)
and adjustments were made to reflect usual dietary intakes. However, while every effort was made to collect accurate records of food intake, the value of the intake data is currently constrained by the lack of comprehensive food composition data.
In conclusion, despite reports of a decline in fish consumption, the Seychellois population had a weekly average (SD) fish intake of 527 (327) g. This intake is almost four times greater than those observed in the UK(57)
. Fat intakes were higher than previously reported (26)
and in most subjects exceeded the UK DRV for fat as a percentage of energy intake for both total (<35 %) and saturated (<10 %) fat. Indeed, macronutrient intakes in pregnant women in Seychelles were similar to intakes reported among pregnant women in the UK(45)
. These findings are reflective of a move towards a more Western-type diet and the emergence of an increased prevalence or risk factors for CHD in the Seychelles(26)
. Our observation that fish consumption was significantly higher in the subset of subjects who met nutrient recommendations for Fe, Zn, iodine and Se is an important finding and highlights the critical role of fish in ensuring optimal dietary intakes of key micronutrients during pregnancy. Furthermore, as a source of protein in the Seychellois diet, fish was equivalent to meat but without the associated higher energy and fat content. These findings are of vital public health importance to the Seychellois and emphasise the necessity in maintaining current levels of fish consumption in this population. However, the overall trend towards a lower consumption of fish could become problematic in the future. These findings suggest caution in establishing public health policies that promote limiting fish intake during pregnancy to reduce exposure to methyl-mercury. Such policies may result in concomitant decreases in important micronutrient intakes and increased energy and fat intakes. Emphasis on the benefits of fish consumption should, therefore, be prioritised.