Development and effect of an N-3 fatty acid-rich spread on the nutritional and cognitive status of school children

[摘要] Long-chain polyunsaturated fatty acids (LCPUFA), especially the n-3 LCPUFA metabolicproducts eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) play an importantrole as regulators in many biological processes. To date hake (Merluccius capensis) heads, arich source of EPA and DHA, have been discarded at sea. The South African Fisheries PolicyDevelopment Committee concerned with the environmental impact of this practice hasrendered it undesirable. The high prevalence of under-nutrition amongst children in SouthAfrica can be addressed by the supplementation of their diet with this unexploited fish source.The aim of the current study was to develop a microbiologically safe and sensory acceptablesandwich spread using fish flour prepared from fish heads, as a prime ingredient. Theintervention trial aimed to compare the effects of an increased dietary intake of n-3 LCPUFA,specifically DHA, on the blood fatty acid levels and absenteeism (as indicator of immunefunction), as well as the cognitive status, of the subjects. The microbiological content of thesandwich spread was determined after storage for 20 d at 5°C and 15 d at 25°C. Sensoryevaluation was performed by consumers (n = 95; M:F = 44:51; 6 – 9 yr) to determineacceptance of the five different flavours individually incorporated into the sandwich spread tomask the fishy note and to provide different flavour options. For the intervention trialsubjects (n = 351) were stratified within class group (A - E) and gender and randomlyassigned to two treatment categories, an experimental group (EG; n = 174) receiving 25 gsandwich spread.d-1 (191.66 mg DHA. d-1) and a control group (CG; n = 177) receiving ananalogous placebo. On school days (104 d), each subject received two sandwiches consistingof two slices of bread (ca. 60 g), spread with 25 g of either the placebo or the experimentalspread. Blood samples were drawn at baseline and post intervention. Plasma fatty acid andred blood cell (RBC) membrane status, C-reactive protein levels, as well as vitamin andmicronutrient status, were determined. Trained test administrators conducted a battery ofcognitive tests. According to South African Government health standards, the sandwichspread remained microbiologically safe after storage. Male and female consumer respondentsrevealed a significant difference between gender preferences of the five different spreadflavours (p <0.05). Significant treatment effects (p <0.05) were observed in n-3 LCPUFAstatus of the EG, as well as for their absenteeism from school. The two subtests of theHopkins Verbal Learning test, Recognition and Discrimination Index, showed significantdifferences between the EG and CG (p <0.05) post intervention in the Grade 2 subjects. TheSpelling tests also showed a significant difference between the two groups (p <0.05). In thecurrent study a microbiologically safe and sensory acceptable sandwich spread was developedand tested during an intervention trial, and could possibly in future, provide a healthier option in the School Nutritional Programme. This study proved that supplementation of children (6 -9 yr) with n-3 LCPUFA, with specific reference to EPA and DHA from a marine source,could have a beneficial effect on their fatty acid status and absenteeism from school. Basedon the outcomes of the Hopkins Verbal Learning test and Spelling test, the current studyproved that an n-3 fatty acid-rich spread improved the learning ability and memory ofchildren.

[发布机构] Stellenbosch University