The addition of milk or yogurt to a plant-based diet increases zinc bioavailability but does not affect iron bioavailability in women

Caseinophosphopeptides Overcome Calcium Phytate Inhibition on Zinc Bioavailability by Retaining Zinc from Coprecipitation as Zinc/Calcium Phytate Nanocomplexes

Caseinophosphopeptides have shown great potential to increase zinc bioavailability from phytate-rich diets, but the mechanism of action remains unclear. Here, caseinophosphopeptides from a sodium caseinate hydrolysate dose-dependently retained zinc in solution against calcium phytate coprecipitation under physiologically relevant conditions. The 3 kDa ultrafiltration separation unveiled no added low-molecular-weight chelates of zinc and calcium by caseinophosphopeptides. Tyndall effect, dynamic light scattering measurements, transmission electron microscopy observation, electron diffraction pattern, X-ray diffraction spectrum, and energy-dispersive X-ray analysis demonstrated the caseinophosphopeptides-mediated formation of single-crystal zinc/calcium phytate nanocomplexes (Zn/CaPA-NCs) with a size and ζ-potential of 10-30 nm and -25 mV, respectively. Caseinophosphopeptides-stabilized Zn/CaPA-NCs were found to deliver bioavailable nanoparticulate zinc in mouse jejunal loop ex vivo model and polarized Caco-2 cells, and the treatments with specific inhibitors revealed that intestinal zinc absorption from Zn/CaPA-NCs invoked macropinocytosis, lysosomal release into the cytosol, and transcytosis. Overall, our study proposes a new paradigm for the benefit of caseinophosphopeptides for zinc bioaccessibility and bioavailability in phytate-rich diets.

Zinc Fortification: Current Trends and Strategies

Zinc, through its structural and cofactor roles, affects a broad range of critical physiological functions, including growth, metabolism, immune and neurological functions. Zinc deficiency is widespread among populations around the world, and it may, therefore, underlie much of the global burden of malnutrition. Current zinc fortification strategies include biofortification and fortification with zinc salts with a primary focus on staple foods, such as wheat or rice and their products. However, zinc fortification presents unique challenges. Due to the influences of phytate and protein on zinc absorption, successful zinc fortification strategies should consider the impact on zinc bioavailability in the whole diet. When zinc is absorbed with food, shifts in plasma zinc concentrations are minor. However, co-absorbing zinc with food may preferentially direct zinc to cellular compartments where zinc-dependent metabolic processes primarily occur. Although the current lack of sensitive biomarkers of zinc nutritional status reduces the capacity to assess the impact of fortifying foods with zinc, new approaches for assessing zinc utilization are increasing. In this article, we review the tools available for assessing bioavailable zinc, approaches for evaluating the zinc nutritional status of populations consuming zinc fortified foods, and recent trends in fortification strategies to increase zinc absorption.

Influence of Dairy Products on Bioavailability of Zinc from Other Food Products: A Review of Complementarity at a Meal Level

In this paper, we reviewed the role of dairy products in dietary zinc absorption. Dairy products can have a reasonable contribution for dietary zinc intake in Western diets, where dairy consumption is high. However, the co-ingestion of dairy products can also improve zinc absorption from other food products. Such improvements have been observed when dairy products (e.g., milk or yoghurt) were ingested together with food such as rice, tortillas or bread products, all of which are considered to be high-phytate foods with low inherent zinc absorption. For foods low in phytate, the co-ingestion of dairy products did not improve zinc absorption. Improved zinc absorption of zinc from high-phytate foods following co-ingestion with dairy products may be related to the beneficial effects of the citrate and phosphopeptides present in dairy products. Considering that the main dietary zinc sources in areas in the world where zinc deficiency is most prevalent are typically high in phytate, the inclusion of dairy products in meals may be a viable dietary strategy to improve zinc absorption.

Dietary Phytochemicals in Zinc Homeostasis: A Strategy for Prostate Cancer Management

Studies have suggested an important role of the trace element zinc (Zn) in prostate biology and functions. Zn has been shown to exist in very high concentrations in the healthy prostate and is important for several prostatic functions. In prostate cancer (PCa), Zn levels are significantly decreased and inversely correlated with disease progression. Ideally, restoration of adequate Zn levels in premalignant/malignant prostate cells could abort prostate malignancy. However, studies have shown that Zn supplementation is not an efficient way to significantly increase Zn concentrations in PCa. Based on a limited number of investigations, the reason for the lower levels of Zn in PCa is believed to be the dysregulation of Zn transporters (especially ZIP and ZnT family of proteins), metallothioneins (for storing and releasing Zn), and their regulators (e.g., Zn finger transcription factor RREB1). Interestingly, the level of Zn in cells has been shown to be modulated by naturally occurring dietary phytochemicals. In this review, we discussed the effect of selected phytochemicals (quercetin, resveratrol, epigallocatechin-3-gallate and curcumin) on Zn functioning and proposes that Zn in combination with specific dietary phytochemicals may lead to enhanced Zn bioaccumulation in the prostate, and therefore, may inhibit PCa.

A Review of Nutrients and Compounds, Which Promote or Inhibit Intestinal Iron Absorption: Making a Platform for Dietary Measures That Can Reduce Iron Uptake in Patients with Genetic Haemochromatosis

Objective

To provide an overview of nutrients and compounds, which influence human intestinal iron absorption, thereby making a platform for elaboration of dietary recommendations that can reduce iron uptake in patients with genetic haemochromatosis.

Design

Review. Setting. A literature search in PubMed and Google Scholar of papers dealing with iron absorption.

Results

The most important promoters of iron absorption in foods are ascorbic acid, lactic acid (produced by fermentation), meat factors in animal meat, the presence of heme iron, and alcohol which stimulate iron uptake by inhibition of hepcidin expression. The most important inhibitors of iron uptake are phytic acid/phytates, polyphenols/tannins, proteins from soya beans, milk, eggs, and calcium. Oxalic acid/oxalate does not seem to influence iron uptake. Turmeric/curcumin may stimulate iron uptake through a decrease in hepcidin expression and inhibit uptake by complex formation with iron, but the net effect has not been clarified.

Conclusions

In haemochromatosis, iron absorption is enhanced due to a decreased expression of hepcidin. Dietary modifications that lower iron intake and decrease iron bioavailability may provide additional measures to reduce iron uptake from the foods. This could stimulate the patients' active cooperation in the treatment of their disorder and reduce the number of phlebotomies.

Iron encapsulated microstructured gel beads using an emulsification-gelation technique for an alginate-caseinate matrix

Iron-deficiency anemia is an important health problem in global public issues, and development of iron fortifiers in diets is essential for the decrease of iron deficiency. However, there are problems for iron fortification in food because the common bioavailable iron compounds would contribute to iron-promoted lipid oxidation and unpleasant iron odor, presenting an adverse food quality. Ferrous fumarate loaded microstructured gel beads were prepared by an emulsification-gelation method using an alginate-caseinate matrix, and the gel network was formed by crosslinking of Ca²⁺ or Fe²⁺. Internal gelated beads showed relatively symmetrical and homogeneous spheres with no adhesion due to the simultaneous release of Fe²⁺ to initiate gelation in situ. External gelated beads displayed an irregular and adhesive structure, probably because the random contact between Na-ALG and Ca²⁺ occurred on the droplet surface, and the immediately gelated hardening layer provided a delay for further Ca²⁺ diffusion. The gel beads exhibited a lag phase in the promotion of lipid oxidation of the emulsion and restrained the iron odor release from ferrous fumarate. Ferrous ion release from microstructured gel beads in the simulated gastric juice was obviously delayed before a more progressive high release in the simulated intestinal juice, beneficial for iron absorption in the duodenum. The iron encapsulated microstructured gel beads might be developed as a promising safe iron fortifier by relieving lipid oxidation and iron odor.

Prevention of Zinc Precipitation with Calcium Phosphate by Casein Hydrolysate Improves Zinc Absorption in Mouse Small Intestine ex Vivo via a Nanoparticle-Mediated Mechanism

Casein phosphopeptides are known to enhance zinc absorption, but the underlying mechanism remains unclear. Here, a gastrointestinal casein hydrolysate (CH) was found to keep zinc in solution despite heavy precipitation of calcium and phosphate, the omnipresent mineral nutrients that could co-precipitate zinc out of solution instantly and almost completely under physiologically relevant conditions. Dynamic light scattering, transmission electron microscopy, and energy-dispersive X-ray analysis displayed the CH-mediated formation of zinc/calcium phosphate (Zn/CaP) nanocomplexes aggregated from rather small nanoclusters. The ex vivo mouse ileal loop experiments revealed enhanced intestinal zinc absorption by CH's prevention of zinc co-precipitation with CaP, and the treatments with specific inhibitors unveiled the involvement of macropinocytic internalization, lysosomal degradation, and transcytosis in the intestinal uptake of zinc from Zn/CaP nanocomplexes. A low calcium-to-phosphorus ratio adversely affected CH's efficiency to enhance zinc solubility and absorption. Overall, our study provides a new paradigm for casein phosphopeptides to improve zinc bioavailability.

Zinc Absorption from Milk Is Affected by Dilution but Not by Thermal Processing, and Milk Enhances Absorption of Zinc from High-Phytate Rice in Young Dutch Women

Background: Milk has been suggested to increase zinc absorption. The effect of processing and the ability of milk to enhance zinc absorption from other foods has not been measured directly in humans.Objective: We aimed to assess zinc absorption from 1) milk undergoing various processing and preparatory steps and 2) from intrinsically labeled high-phytate rice consumed with milk or water.Methods: Two randomized crossover studies were conducted in healthy young women [age:18-25 y; body mass index (in kg/m²): 20-25]: 1) a milk study (n = 19) comparing the consumption of 800 mL full-fat ultra-high temperature (UHT) milk [heat-treated milk (HTM)], full-fat UHT milk diluted 1:1 with water [heat-treated milk and water (MW)], water, or unprocessed (raw) milk (UM), each extrinsically labeled with ⁶⁷Zn, and 2) a rice study (n = 18) comparing the consumption of 90 g intrinsically ⁶⁷Zn-labeled rice with 600 mL of water [rice and water (RW)] or full-fat UHT milk [rice and milk (RM)]. The fractional absorption of zinc (FAZ) was measured with the double-isotope tracer ratio method. In vitro, we assessed zinc extraction from rice blended into water, UM, or HTM with or without phytate.Results: FAZ from HTM was 25.5% (95% CI: 21.6%, 29.4%) and was not different from UM (27.8%; 95% CI: 24.2%, 31.4%). FAZ from water was higher (72.3%; 95% CI: 68.7%, 75.9%), whereas FAZ from MW was lower (19.7%; 95% CI: 17.5%, 21.9%) than HTM and UM (both P < 0.01). FAZ from RM (20.7%; 95% CI: 18.8%, 22.7%) was significantly higher than from RW (12.8%; 95% CI: 10.8%, 14.6%; P < 0.01). In vitro, HTM and UM showed several orders of magnitude higher extraction of zinc from rice with HTM than from rice with water at various phytate concentrations.Conclusions: Milk enhanced human FAZ from high-phytate rice by 62% compared with water. Diluting milk with water decreases its absorption-enhancing proprieties, whereas UHT processing does not. This trial was registered at the Dutch trial registry as NTR4267 (http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=4267).

Effect of NaFeEDTA-fortified soy sauce on zinc absorption in children

NaFeEDTA has been applied in many foods as an iron fortificant and is used to prevent iron deficiency in Fe-depleted populations. In China, soy sauce is fortified with NaFeEDTA to control iron deficiency. However, it is unclear whether Fe-fortified soy sauce affects zinc absorption. To investigate whether NaFeEDTA-fortified soy sauce affects zinc absorption in children, sixty children were enrolled in this study and randomly assigned to three groups (10 male children and 10 female children in each group). All children received daily 3 mg of (67)Zn and 1.2 mg of dysprosium orally, while the children in the three groups were supplemented with NaFeEDTA-fortified soy sauce (6 mg Fe, NaFeEDTA group), FeSO₄-fortified soy sauce (6 mg Fe, FeSO₄ group), and no iron-fortified soy sauce (control group), respectively. Fecal samples were collected during the experimental period and analyzed for the Zn content, (67)Zn isotope ratio and dysprosium content. The Fe intake from NaFeEDTA-fortified and FeSO₄-fortified groups was significantly higher than that in the control group (P < 0.0001). The daily total Zn intake was not significantly different among the three groups. There were no significant differences in fractional Zn absorption (FZA) (P = 0.3895), dysprosium recovery (P = 0.7498) and Zn absorption (P = 0.5940) among the three groups. Therefore, NaFeEDTA-fortified soy sauce does not affect Zn bioavailability in children.

The scale of the evidence base on the health effects of conventional yogurt consumption: findings of a scoping review

BACKGROUND

The health effects of conventional yogurt have been investigated for over a century; however, few systematic reviews have been conducted to assess the extent of the health benefits of yogurt.

OBJECTIVE

The aim of this scoping review was to assess the volume of available evidence on the health effects of conventional yogurt.

METHODS

The review was guided by a protocol agreed a priori and informed by an extensive literature search conducted in November 2013. Randomized controlled trials were selected and categorized according to the eligibility criteria established in the protocol.

RESULTS

213 studies were identified as relevant to the scoping question. The number of eligible studies identified for each outcome were: bone health (14 studies), weight management and nutrition related health outcomes (81 studies), metabolic health (6 studies); cardiovascular health (57 studies); gastrointestinal health (24 studies); cancer (39 studies); diabetes (13 studies), Parkinson's disease risk (3 studies), all-cause mortality (3 studies), skin complaints (3 studies), respiratory complaints (3 studies), joint pain/function (2 studies); the remaining 8 studies reported a variety of other outcomes. For studies of a similar design and which assessed the same outcomes in similar population groups, we report the potential for the combining of data across studies in systematic reviews.

CONCLUSIONS

This scoping review has revealed the extensive evidence base for many outcomes which could be the focus of systematic reviews exploring the health effects of conventional yogurt consumption.

Colorectal cancer and nonfermented milk, solid cheese, and fermented milk consumption: a systematic review and meta-analysis of prospective studies

Colorectal cancer is the second most prevalent cancer worldwide. A systematic review and meta-analysis of prospective studies was conducted to examine the association between intake of different types of dairy foods during adulthood and the development of colorectal cancer, specifically comparing nonfermented milk, solid cheese, and fermented milk. Seven databases were systematically searched and 15 cohort studies selected for inclusion, involving over 900,000 subjects and over 5200 colorectal cancer cases. Meta-analysis resulted in an overall relative risk of colon cancer of 0.74 (95% confidence interval 0.60-0.91) in men consuming nonfermented milk (highest intake category averaging 525 g/day). No association was found between consumption of nonfermented milk and rectal cancer in men or nonfermented milk and colon or rectal cancer in women. No protective association was found between consumption of solid cheese or fermented milk and colorectal cancer. Reasons for the differences in the impact of nonfermented milk, solid cheese, and fermented milk in the colon are discussed. This meta-analysis supports the inverse association between nonfermented milk consumption and risk of colon cancer in men, and provides an evidence base to assist in the formulation of dietary guidelines involving dairy foods.

Low serum concentrations of carotenoids and vitamin E are associated with high adiposity in Mexican-American children

Mexican-American children have a high prevalence of overweight/obesity. Micronutrient deficiencies may be contributing to the development of greater adiposity in these children. This study investigated the relations between adiposity and serum concentrations of carotenoids, retinol, and vitamin E among Mexican-American children 8-15 y of age included in the 2001-2004 U.S. NHANES. Associations of the outcomes of children's body mass index (BMI), truncal fat mass (TrFM), and total body fat mass (TBFM) with serum concentrations of α-carotene, cis-β-carotene, trans-β-carotene, retinol, and α-tocopherol were determined by using linear, quantile, and multinomial regression models. BMI was inversely associated with serum concentrations of α-carotene (β = -0.88, P < 0.05), trans-β-carotene (β = -2.21, P < 0.01), cis-β-carotene (β = -2.10, P < 0.01), and α-tocopherol adjusted for total cholesterol ratio (β = -3.66, P < 0.01), respectively. Similar inverse associations were found with TrFM and TBFM. Higher cis-β-carotene and α-tocopherol serum concentrations were associated with reduced probability of overweight (OR: 0.57; 95% CI: 0.37, 0.89; P < 0.05; and OR: 0.56; 95% CI: 0.37, 0.86; P < 0.05; respectively) and obesity (OR: 0.39; 95% CI: 0.26, 0.58; P < 0.01; and OR: 0.38; 95% CI: 0.24, 0.60; P < 0.01; respectively). Higher retinol serum concentrations were associated with increased probability of overweight and obesity (OR: 2.01; 95% CI: 1.26, 3.22; P < 0.01; and OR: 2.90; 95% CI: 1.65, 5.09; P < 0.01; respectively). Significant inverse associations were found between serum concentrations of carotenoids and vitamin E and adiposity among Mexican-American children, but serum retinol concentrations were positively associated with adiposity. Future research is needed to understand the causes and consequences of micronutrient status on adiposity and comorbidities.

Effect of vegetarian diets on zinc status: a systematic review and meta-analysis of studies in humans

Plant-based diets contain less saturated fat and cholesterol and more folate, fibre and phytochemicals than omnivorous diets, but some micronutrients, especially zinc, are poorly bioavailable. The findings of studies exploring the zinc intake and zinc status in populations that habitually consume vegetarian diets are inconsistent. This study aims to investigate the effects of plant-based diets on dietary zinc intake and status in humans using systematic review and meta-analysis techniques. Thirty-four studies were included in the systematic review. Of these, 26 studies (reporting 48 comparisons) compared males and/or females consuming vegetarian diets with non-vegetarian groups and were included in meta-analyses. Dietary zinc intakes and serum zinc concentrations were significantly lower (-0.88 ± 0.15 mg day(-1), P < 0.001 and -0.93 ± 0.27 µmol L(-1), P = 0.001 respectively; mean ± standard error) in populations that followed habitual vegetarian diets compared with non-vegetarians. Secondary analyses showed greater impact of vegetarian diets on the zinc intake and status of females, vegetarians from developing countries and vegans. Populations that habitually consume vegetarian diets have low zinc intakes and status. Not all vegetarian categories impact zinc status to the same extent, but a lack of consistency in defining vegetarian diets for research purposes makes dietary assessment difficult. Dietary practices that increase zinc bioavailability, the consumption of foods fortified with zinc or low-dose supplementation are strategies that should be considered for improving the zinc status of vegetarians with low zinc intakes or serum zinc concentrations at the lower end of the reference range.

Iron and zinc nutrition in the economically-developed world: a review

This review compares iron and zinc food sources, dietary intakes, dietary recommendations, nutritional status, bioavailability and interactions, with a focus on adults in economically-developed countries. The main sources of iron and zinc are cereals and meat, with fortificant iron and zinc potentially making an important contribution. Current fortification practices are concerning as there is little regulation or monitoring of intakes. In the countries included in this review, the proportion of individuals with iron intakes below recommendations was similar to the proportion of individuals with suboptimal iron status. Due to a lack of population zinc status information, similar comparisons cannot be made for zinc intakes and status. Significant data indicate that inhibitors of iron absorption include phytate, polyphenols, soy protein and calcium, and enhancers include animal tissue and ascorbic acid. It appears that of these, only phytate and soy protein also inhibit zinc absorption. Most data are derived from single-meal studies, which tend to amplify impacts on iron absorption in contrast to studies that utilize a realistic food matrix. These interactions need to be substantiated by studies that account for whole diets, however in the interim, it may be prudent for those at risk of iron deficiency to maximize absorption by reducing consumption of inhibitors and including enhancers at mealtimes.

A combination of a dairy product fermented by lactobacilli and galactooligosaccharides shows additive effects on mineral balances in growing rats with hypochlorhydria induced by a proton pump inhibitor

This study aimed to investigate the effects of a combination of a dairy product fermented by lactobacilli (DFL) and galactooligosaccharides (GOS) on mineral balances in growing rats with hypochlorhydria induced by a proton pump inhibitor (PPI). Three-week-old male rats were assigned to receive one of six diets: a control diet, control diets containing 1.6 or 5.0 % GOS, a DFL diet and DFL diets containing 1.6 or 5.0 % GOS for 9 days. From day 5 of the feeding period, half of the rats fed with control diets were subcutaneously administered with saline, whereas the remaining rats were administered with PPI for 5 days. Calcium (Ca), phosphorus (P), magnesium (Mg), iron (Fe) and zinc (Zn) balances were determined from days 6 to 9. PPI administration significantly decreased the apparent absorption of Ca and Fe and increased urinary P excretion, resulting in decreased Ca, Fe and P retention. GOS dose-dependently increased the apparent absorption of Ca, Mg and Fe and urinary Mg excretion and decreased urinary P excretion. DFL significantly increased the apparent absorption of Ca and Mg and urinary Mg excretion. The combination of DFL and GOS additively affected these parameters, resulting in increased Ca, P and Fe retention, and it further increased the apparent absorption and retention of Zn at 5.0 % GOS. In conclusion, the combination of DFL and GOS improves Ca, P and Fe retention in an additive manner and increases the Zn retention in growing rats with hypochlorhydria induced by PPI.

Impact of micronutrient fortification of yoghurt on micronutrient status markers and growth - a randomized double blind controlled trial among school children in Bangladesh

Background

Interventions providing foods fortified with multiple micronutrients can be a cost-effective and sustainable strategy to improve micronutrient status and physical growth of school children. We evaluated the effect of micronutrient-fortified yoghurt on the biochemical status of important micronutrients (iron, zinc, iodine, vitamin A) as well as growth indicators among school children in Bogra district of Bangladesh.

Methods

In a double-masked randomized controlled trial (RCT) conducted in 4 primary schools, 1010 children from classes 1–4 (age 6–9 years) were randomly allocated to receive either micronutrient fortified yoghurt (FY, n = 501) or non-fortified yoghurt (NFY, n = 509). For one year, children were fed with 60 g yoghurt everyday providing 30% RDA for iron, zinc, iodine and vitamin A. Anthropometric measurements and blood/urine samples were collected at base-, mid- and end-line. All children (FY, n = 278, NFY, n = 293) consenting for the end-line blood sample were included in the present analyses.

Results

Both groups were comparable at baseline for socio-economic status variables, micronutrient status markers and anthropometry measures. Compliance was similar in both the groups. At baseline 53.4% of the population was anemic; 2.1% was iron deficient (ferritin <15.0 μg/L and TfR > 8.3 mg/L). Children in the FY group showed improvement in Hb (mean difference: 1.5; 95% CI: 0.4-2.5; p = 0.006) as compared to NFY group. Retinol binding protein (mean diff: 0.05; 95% CI: 0.002-0.09; p = 0.04) and iodine levels (mean difference: 39.87; 95% CI: 20.39-59.35; p < 0.001) decreased between base and end-line but the decrease was significantly less in the FY group. Compared to NFY, the FY group had better height gain velocity (mean diff: 0.32; 95% CI: 0.05-0.60; p = 0.02) and height-for-age z-scores (mean diff: 0.18; 95% CI: 0.02-0.33; p = 0.03). There was no difference in weight gain velocity, weight-for-age z-scores or Body Mass Index z-scores.

Conclusion

In the absence of iron deficiency at baseline the impact on iron status would not be expected to be observed and hence cannot be evaluated. Improved Hb concentrations in the absence of a change in iron status suggest improved utilization of iron possibly due to vitamin A and zinc availability. Fortification improved height gain without affecting weight gain.

Trial registration

ClinicalTrial.gov: NCT00980733

Yogurt protects against growth retardation in weanling rats fed diets high in phytic acid

The purpose of this study was to determine the effects of adding yogurt to animal diets that were high in phytic acid (PA) and adequate in zinc (38 microg Zn/g). The PA:Zn molar ratio was 60:1. Zinc status was determined by documenting growth and measuring the zinc concentration in bone (tibia) and plasma. For 25 days, six groups (n=6) of Sprague-Dawley weanling rats were fed one of six AIN-76 diets. Half of the diets contained PA. Four of the diets contained yogurt with either active or heat-treated (inactive) cultures added at 25% of the diet. The diets were as follows: (a) AIN, (b) AIN with active yogurt, (c) AIN and inactive yogurt, (d) AIN with PA, (e) AIN with PA plus active yogurt and (f) AIN with PA plus inactive yogurt. Body weight, weight gain and zinc concentration in bone and plasma were measured, and food efficiency ratio was calculated. Rats fed diets with PA and yogurt had normal growth compared to the control group. Growth retardation was evident in the group fed the diet with PA and no yogurt. This group had significantly lower body weight compared to all other groups (P<.05). Rats fed diets with PA, with or without yogurt, had significantly lower zinc concentration in bone and plasma (P<.05). Adding yogurt to diets high in PA resulted in normal growth in weanling rats; however, zinc concentration in bone and plasma was still suboptimal.

Yoghurt and dairy snacks presented for sale to an Australian consumer: are they becoming less healthy?

OBJECTIVE

To assess the nutrient profile of yoghurts and dairy desserts.

DESIGN

Nutrition information panels and product labels on yoghurts and dairy desserts offered for sale were surveyed in 2005 and 2008 and nutrients analysed by two nutrient profiling systems.

SETTING

A large supermarket in metropolitan Melbourne, Australia.

RESULTS

In total, 248 and 140 dairy snacks (yoghurt, fromage frais or dairy desserts) were surveyed in 2005 and 2008, respectively. Over this time, median packet size rose significantly (P < or = 0.001). In yoghurts, median energy and total fat content also increased while protein decreased (all P < 0.05). The proportion of 'full-fat' products rose from 36 % to 46%. Because of the addition of sugar, most 'reduced-fat' yoghurts had energy content similar to many 'full-fat' yoghurts. Overall, the proportion of yoghurts and dairy desserts that were 'less healthy' (i.e. displaying one or more 'red traffic lights' for high fat, saturated fat, salt and sugar content) rose from 12% in 2005 to 23% in 2008. Only 1-2% could be deemed 'healthy' by the most stringent criterion (displaying four 'green traffic lights'), while 21% (2005) or 28% (2008) were 'healthy' by a nutrient profiling system that included a score for protein. Sucrose, the most common sweetener, was found in levels up to 29 g/100 g. Claims on packaging mainly related to Ca, fat or protein content. Few labels referred to sugar content.

CONCLUSIONS

The deterioration in nutrient quality of yoghurts needs to be redressed.

A Review of Interventions Based on Dietary Diversification or Modification Strategies with the Potential to Enhance Intakes of Total and Absorbable Zinc

Dietary diversification or modification has the potential to prevent deficiencies of zinc and other coexisting limiting micronutrients simultaneously, without risk of antagonistic interactions. In this review, we have addressed the following. The first section focuses on strategies with the potential to enhance intake and/or bioavailability of zinc, and includes interventions (with and without nutrition education) based on agriculture, production or promotion of animal-source foods through animal husbandry or aquaculture, and commercial and household processing strategies to enhance zinc absorption. Outcome indicators include intakes of foods or nutrients (although rarely zinc) and, in some cases, zinc status, or zinc-related functional responses. The next two sections address whether dietary diversification or modification can achieve increases in absorbable zinc that are sufficient to enhance zinc status or zinc-related functional responses in breastfed infants and toddlers and in older children and women of reproductive age. Evidence for the impact of dietary diversification or modification on behavior change and on nutritional status in the short and long term, and the possible role of modifying factors (e.g., baseline nutritional status, socioeconomic status, infection, sex, age, and life-stage group) is the emphasis of the next section. The following section highlights the evidence for three potential adverse effects of dietary diversification or modification: aflatoxin contamination from germinated cereals, loss of water-soluble nutrients, and displacement of breastmilk. Finally, an example of a dietary diversification or modification program (Homestead Food Production) developed and implemented by Helen Keller International is given, together with the critical steps needed to scale up dietary diversification or modification for programs and future research needs.