Associations of dietary diversity with anaemia and iron status among 5- to 12-year-old schoolchildren in South Africa.

OBJECTIVE: To examine the associations of dietary diversity with anaemia and iron status among primary school-aged children in South Africa. DESIGN: An analysis was conducted with pooled individual data from the baseline surveys from three previously conducted independent intervention studies. Two different dietary diversity scores (DDS) were calculated based on data from 1-day (1-d) and 3-day (3-d) dietary recall periods, respectively. Logistic regression analysis was performed to examine the associations of dietary diversity with anaemia and iron status. SETTING: KwaZulu-Natal and North West provinces, South Africa. PARTICIPANTS: Children (n 578) 5- to 12-year-old. RESULTS: A DDS ≤ 4 was associated with higher odds of being anaemic (1-d P = 0·001; 3-d P = 0·006) and being iron deficient (ID) (3-d P < 0·001). For both recall periods, consumption of 'vegetables and fruits other than vitamin A-rich' and 'animal-source foods (ASF)' was associated with lower odds of being anaemic (both P = 0·002), and 'organ meats' with lower odds of being ID (1-d P = 0·045; 3-d P < 0·001). Consumption of 'meat, chicken and fish' was associated with lower odds of being anaemic (P = 0·045), and 'vegetables and fruits other than vitamin A-rich', 'legumes, nuts and seeds' and 'ASF' with lower odds of being ID for the 3-d recall period only (P = 0·038, P = 0·020 and P = 0·003, respectively). CONCLUSION: In order to improve anaemia and iron status among primary school-aged children, dietary diversification, with emphasis on consumption of vegetables, fruits and ASF (including organ meats), should be promoted.

Point-of-use micronutrient fortification: lessons learned in implementing a preschool-based pilot trial in South Africa.

This current pilot trial assessed the feasibility of implementing a point-of-use (PoU) micronutrient fortification in preschool settings. Preschool children (n = 151) aged 36-79 months were randomized into intervention (n = 76) and control (n = 75) groups, both receiving breakfast maize-porridge with added micronutrient or placebo powder for 52 school days. Process evaluation and early childhood development indicators were used to assess trial feasibility. Process evaluation results showed that the implementation components were feasible and could be delivered with high fidelity. The improvement in hemoglobin concentration in intervention and control groups were not significantly different (P = 0.250). There was medium likelihood for practical significance for the two global cognitive scores assessed: non-verbal index (intervention effects: 7.20; 95% confidence interval: 2.60, 11.81; P = 0.002, effect size: 0.55) and mental processing index (intervention effects: 2.73; 95% confidence interval: 0.25, 5.70; P = 0.072, effect size: 0.36) on the Kaufman Assessment Battery for Children, Second Edition. The lessons from this trial could help in planning/implementing future PoU micronutrient fortification trial among South African preschool children.

Nutrient density, but not cost of diet, is associated with anemia and iron deficiency in school-age children in South Africa.

OBJECTIVES: This study aimed to investigate the relationship of nutrient density and diet cost with anemia and iron deficiency (ID) in children. METHODS: Dietary intake data of 5- to 12-y-old children (n = 578) from three independent studies in low-income communities were pooled. Nutrient densities were calculated using the Nutrient Rich Foods index and Nutrient Rich Diet index, with higher scores indicating more nutrient-dense foods and diets. Food prices and food intake data were used to calculate ratios of nutrient density to price for foods and diets. Descriptive and correlation analyses examined associations of nutrient density and diet cost with anemia and ID. RESULTS: Most children (>50%) consumed starchy staples (100%), vegetables that are not vitamin A rich (63.9%), and legumes (58.1%), with mean NRF9.3 scores ranging from 31.9 to 56.3. Cheese, eggs, organ meat, fish, dark-green leafy vegetables, and vitamin A-rich vegetables and fruits had mean NRF9.3 scores ranging from 112.6 to 184.7, but each was consumed by less than a third of the children. Children with anemia or ID had lower NRD9.3 scores than children without (P < 0.001 and P = 0.039, respectively). Diet cost did not differ according to anemia and iron status, but nutrient-density-to-price ratio was lower in children with anemia than without (P = 0.001). CONCLUSIONS: Careful selection of nutrient-dense foods as substitutes for foods with lower nutrient density could make it possible for children to consume a diet richer in specific nutrients and help prevent anemia and ID without affecting diet cost.

Nutrient patterns and their relation to anemia and iron status in 5- to 12-y-old children in South Africa.

OBJECTIVE: The aim of this study was to assess nutrient patterns and their relation to anemia and iron status of school children using pooled data from three study populations in South Africa. METHODS: Data from 5- to 12-y-old children (N = 578) from three independent studies conducted in two provinces in South Africa were pooled. Data used in the analysis were dietary intake, hemoglobin, and plasma ferritin concentrations. Nutrient patterns were determined using factor analysis. Logistic regression analysis was performed to determine relationships of nutrient patterns with anemia and iron deficiency. RESULTS: In the pooled group, 13.8% of the children were anemic and 27.7% were iron deficient (ID). More than half of children did not meet the Estimated Average Requirement for various nutrients, including vitamins A, C, B12, folate, and zinc, although only 17.7% of children had an iron intake below the requirements. Median intakes for vitamins A and C were lower for anemic than non-anemic children (P = 0.03 and 0.02, respectively) and for ID versus non-ID children (P = 0.03 and 0.046, respectively). Four nutrient patterns were identified: plant protein, carbohydrate, iron, and B vitamins; animal protein and saturated fat; vitamins A and B12; and calcium and fiber. The vitamin A and B12 nutrient pattern was associated with lower odds of being anemic (odds ratio, 0.63; 95% confidence interval, 0.49-0.91; P = 0.035). CONCLUSION: The present results highlighted the potential role of the combination of dietary vitamin A and B12 in the etiology of nutritional anemia in school-age children in South Africa. Nutrient pattern analysis may improve the understanding of the synergistic role of nutrients related to anemia and may assist in planning intervention strategies.

Modulation of baroreflex sensitivity by walnuts versus cashew nuts in subjects with metabolic syndrome.

BACKGROUND: Impaired baroreflex sensitivity (BRS) is associated with cardiovascular diseases and the metabolic syndrome. Because lipid abnormalities have been associated with impaired BRS, this study aimed to determine whether diets known to improve the lipid profile, namely a diet high in polyunsaturated fatty acids (walnuts) or monounsaturated fatty acids (cashew nuts), would improve BRS in subjects with metabolic syndrome (MS). METHODS: A controlled feeding trial with a randomized, controlled, parallel study design was undertaken, which involved 62 subjects with MS. Subjects were stratified according to gender and age and were randomized into three groups receiving a control diet, or a diet high (20% energy) in walnuts or unsalted cashew nuts for 8 weeks while maintaining body weight. The BRS, C-reactive protein (CRP), and MS components were measured before and after the intervention. RESULTS: After the intervention, BRS in the walnut-fed study group decreased (P = .038) and that in the cashew-fed study group increased (P = .036), but the BRS in the control group did not change (P = .56). The percent change of the walnut versus cashew group differed (P = .019). Body mass index, waist circumference, blood pressure, high-density lipoprotein cholesterol, and triacylglycerol did not change. The fasting glucose concentrations of the cashew group increased (P = .03). CONCLUSIONS: The significant improvements in BRS obtained by a diet rich in cashew nuts underline the beneficial cardiovascular effects of nuts. However, the opposite result was obtained with a diet rich in walnuts. These significant changes observed might indicate that BRS is particularly sensitive and influenced by changes in diet without changes in obesity.

Clustering of haemostatic variables and the effect of high cashew and walnut diets on these variables in metabolic syndrome patients.

We investigated the effect of a high walnut and cashew diet on haemostatic variables in people with the metabolic syndrome. Factor analysis was used to determine how the haemostatic variables cluster with other components of the metabolic syndrome and multiple regression to determine possible predictors. This randomized, control, parallel, controlled-feeding trial included 68 subjects who complied with the Third National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol criteria. After a 3-week run-in following the control diet, subjects were divided into three groups receiving either walnuts or cashews (20 energy%) or a control diet for 8 weeks. The nut intervention had no significant effect on von Willebrand factor antigen, fibrinogen, factor VII coagulant activity, plasminogen activator inhibitor 1 activity, tissue plasminogen activator activity or thrombin activatable fibrinolysis inhibitor. Statistically, fibrinogen clustered with the body-mass-correlates and acute phase response factors, and factor VII coagulant activity clustered with high-density lipoprotein cholesterol (HDL-C). Tissue plasminogen activator activity, plasminogen activator inhibitor 1 activity and von Willebrand factor antigen clustered into a separate endothelial function factor. HDL-C and markers of obesity were the strongest predictors of the haemostatic variables. We conclude that high walnut and cashew diets did not influence haemostatic factors in this group of metabolic syndrome subjects. The HDL-C increase and weight loss may be the main focus of dietary intervention for the metabolic syndrome. Furthermore, diet composition may have only limited effects if weight loss is not achieved.

The process of nutrient analysis for controlled feeding trials: a comparative study of two South African nutrient databases with chemical analysis.

BACKGROUND: There is an increased tendency in the field of nutrition research to conduct more outpatient controlled feeding trials. The formulation of accurate diets is essential in order to assemble valid scientific data, which will substantiate hypothesised relationships between a nutrient variable and an outcome. Research dieticians rely on the accuracy of computerised nutrient databases when designing the menu. OBJECTIVE: The reliability of the two computerised nutrient databases available in South Africa containing foods from different food sources were investigated, comparing them with each other and with the reference standard of chemical analysis. METHODS: A seven day Westernized menu providing an energy level of 7500 kJ/day was entered into FoodFinder3 (2002) and Dietary Manager (modified 2006 version) Software programmes. Food prepared according to this menu was chemically analysed for the macronutrient profiles (carbohydrate, fat and protein), fatty acid distribution (saturated fatty acids, mono-unsaturated fatty acids and poly-unsaturated fatty acids) and total fibre, insoluble and soluble fibre in order to compare data. RESULTS: The two nutrient databases' values did not differ significantly from each other despite using different food sources, however, there were differences between the chemically analysed values and the databases' calculated values for selected nutrients. There were no significant differences between the amount of total energy, protein, carbohydrate, poly-unsaturated fatty acids and total fibre. The total fat, saturated fatty acid and mono-unsaturated fatty acid content using both FoodFinder3 and Dietary Manager were statistically and practically significantly higher than the chemical analysis (p<0.05). FoodFinder3 produced significantly lower levels of insoluble and soluble fibre compared to the chemical analysis. CONCLUSION: The use of computerised nutrient databases in menu design for controlled feeding trials is functional and assists the research dietician with this challenging task. However, computer nutrient databases are not reliable enough to exclude the step of menu validation by chemical analysis before the start of the intervention.

Effects of a high walnut and high cashew nut diet on selected markers of the metabolic syndrome: a controlled feeding trial.

We investigated the effects of a high walnut diet and a high unsalted cashew nut diet on selected markers of the metabolic syndrome. In a randomized, parallel, controlled study design, sixty-four subjects having the metabolic syndrome (twenty-nine men, thirty-five women) with a mean age of 45 (sd 10) years and who met the selection criteria were all fed a 3-week run-in control diet. Hereafter, participants were grouped according to gender and age and then randomized into three groups receiving a controlled feeding diet including walnuts, or unsalted cashew nuts or no nuts for 8 weeks. Subjects were required to have lunch at the metabolic ward of the Nutrition Department of the North-West University (Potchefstroom Campus). Both the walnut and the unsalted cashew nut intervention diets had no significant effect on the HDL-cholesterol, TAG, total cholesterol, LDL-cholesterol, serum fructosamine, serum high-sensitivity C-reactive protein, blood pressure and serum uric acid concentrations when compared to the control diet. Low baseline LDL-cholesterol concentrations in the cashew nut group may have masked a possible nut-related benefit. Plasma glucose concentrations increased significantly (P = 0.04) in the cashew nut group compared to the control group. By contrast, serum fructosamine was unchanged in the cashew nut group while the control group had significantly increased (P = 0.04) concentrations of this short-term marker of glycaemic control. Subjects displayed no improvement in the markers of the metabolic syndrome after following a walnut diet or a cashew nut diet compared to a control diet while maintaining body weight.

The effects of high walnut and cashew nut diets on the antioxidant status of subjects with metabolic syndrome.

BACKGROUND: Nut consumption is associated with a protective effect against coronary heart disease, partly due to its high antioxidant content. It is hypothesized that the inclusion of nuts in the diet will improve the antioxidant status of subjects with metabolic syndrome who may be vulnerable to impaired antioxidant status. AIM: The effects of high cashew nut and high walnut diets on the antioxidant status of subjects with metabolic syndrome are investigated. METHODOLOGY: Sixty-four volunteers (29 male and 35 female, 45 +/- 10y) with metabolic syndrome (diagnosed by using the ATP III criteria) received a prudent control diet, prepared in the metabolic kitchen of the North-West University, Potchefstroom campus (NWU-PC) for a period of 3 weeks (run-in). The participants were grouped according to gender and age and randomized into three groups, receiving either the walnut, cashew nut or the control diets for 8 weeks, while maintaining a stable body weight. Nuts provided 20% of daily energy intake. Fasting blood samples were taken after the run-in period (baseline) and at the end of the intervention period and analyzed for various antioxidant capacity markers. RESULTS: The oxygen radical absorbance capacity (ORAC) of the walnut and cashew nut diets were significantly higher than the control diet. Despite this, the walnut and cashew nut diets had no significant effects on serum ORAC, reduced (GSH), oxidized (GSSG) glutathione, GSH:GSSG or diacron reactive metabolites (dRom) (total oxidant status) levels compared to the control group. However, all three groups showed significant improvements in antioxidant status from baseline to end (GSSG and dRom levels decreased; GSG:GSSG ratio and ORAC levels increased). This may be due to a general increased antioxidant intake from the prudent diet compared to the habitual diets. CONCLUSION: Although the inclusion of walnuts and cashew nuts into a prudent diet resulted in an increased antioxidant capacity (ORAC) of the nut diets, compared to the control diet, it did not improve the serum antioxidant profiles of subjects with metabolic syndrome.