Salivary cystatin SN is a factor predicting iron bioavailability after phytic acid rich meals in female participants.

Phytic acid is an inhibitor of iron bioavailability, but it has been suggested that individuals may adapt to phytic acid over time, and that the salivary protein, cystatin SN, may be involved. This study evaluated the relationship between human cystatin SN levels and iron bioavailability after a phytic acid rich meal. Three groups of ten women consumed meals with: (1) 500 mg phytate sprinkles, (2) 500 mg phytate capsules, or (3) no phytic acid. Iron bioavailability was measured by the mealtime percentage of maximum iron recovery; cystatin SN was measured pre-and post-meal by enzyme-linked immunosorbent assay. Pre-to-post meal cystatin SN was positively correlated with improved iron bioavailability in group 1. Pre-to-post meal cystatin SN was correlated with improved iron absorption in groups 1 and 2. Cystatin SN recovery after phytic acid rich meals may be a physiological factor predicting iron bioavailability.

Prevention of dental caries by grape seed extract supplementation: A systematic review.

BACKGROUND: Dental caries are the most prominent chronic disease of children and adults worldwide, and facilitating evidence-based, preventative care for their prevention is critical. Caries are traditionally and successfully prevented by regular fluoride use, but there are opportunities to halt and restore caries with alternative agents in addition to fluoride use. Grape seed extract (GSE) is a readily available plant-based supplement that, due to its concentrated levels of proanthocyanidins, has promising characteristics that may assist in dental caries prevention. AIM: The goal of this review was to investigate whether current research supports use of grape seed extract to prevent dental caries formation. METHODS: A systematic review of articles related to grape seed extract, prevention of dental caries, inhibition of Streptococcus mutans, and remineralization was conducted. Articles were first chosen by inclusion of dental models that used grape seed extract as an intervention, and then by strength of study design. RESULTS: Twenty articles were reviewed. Studies overall supported three unique grape seed extract properties facilitating dental caries prevention. In the first articles reviewed, grape seed extract inhibited proliferation of bacterial biofilms on tooth surfaces. In addition, studies reviewed indicated that grape seed extract promoted dental remineralization. CONCLUSIONS: Caries prevention by grape seed extract may be unique compared with fluoride, and is linked to grape seed extract's bacteriostatic and collagen crosslinking properties. Future research should investigate potential delivery methods, and benefits of combined grape seed extract use with known caries preventative agents, in human participants.

Dental Caries Are Associated with Anemia in Pediatric Patients: A Systematic Literature Review.

BACKGROUND: Dental caries (cavities) and anemia are among the most common chronic diseases seen by health professionals and experienced globally. However, the quality, and current evidence linking pediatric dental caries to anemia, is not well established. Moreover, it is not well known whether anemia seen with dental caries is due to iron deficiency or other causes. OBJECTIVE: This systematic literature review was designed to analyze the relationship between anemia and pediatric dental caries and examine the strength of evidence in current research. METHODS: Articles were sourced from PubMed, the American Dental Association database, American Dental Hygienist's Association database, Science Direct, Cochrane Library, CINAHL, Google Scholar, and Medline ProQuest. Outcomes were pooled for statistical effect size. RESULTS: Nineteen articles were selected from 351 identified. There was a 4.5-fold incidence in anemia diagnosis among children with, compared to without, dental caries. While ferritin and mean corpuscular volume were not significantly different among children with and without dental caries, the average serum iron was nearly 30 ug/dL greater in caries-free children, suggesting that iron deficiency may be more common among children with caries. Studies in the future may benefit from methodological improvements and more specific study questions to further investigate this question.

Complementary Feeding of Sorghum-Based and Corn-Based Fortified Blended Foods Results in Similar Iron, Vitamin A, and Anthropometric Outcomes in the MFFAPP Tanzania Efficacy Study.

BACKGROUND: Fortified blended foods (FBFs) are micronutrient-fortified food aid products containing cereals and pulses. It has been suggested to reformulate FBFs to include whey protein concentrate, use alternative commodities (e.g., sorghum and cowpea), and utilize processing methods such as extrusion to produce them. The Micronutrient Fortified Food Aid Pilot Project (MFFAPP) efficacy study was designed to test the efficacy of complementary feeding of newly formulated FBFs. OBJECTIVES: The aim of this study was to test the effectiveness of 5 newly formulated FBFs in combating iron deficiency anemia and vitamin A deficiency compared with traditionally prepared corn-soy blend plus (CSB+) and no intervention. A secondary aim was to determine the impact on underweight, stunting, wasting, and middle-upper arm circumference. METHODS: A 20-wk, partially randomized cluster study was completed. Two age groups (aged 6-23 and 24-53 mo) with hemoglobin status <10.3 g/dL, and weight-for-height z scores >-3 were enrolled and assigned to diet groups. Biochemical and anthropometric measurements were collected at 0, 10, and 20 wk. RESULTS: Both hemoglobin concentrations and anemia ORs were significantly improved in all intervention groups except for CSB+ and the no-intervention groups at week 20. Only extruded corn-soy blend 14 and the no-intervention age groups failed to significantly decrease vitamin A deficiency risk (P < 0.04). There were no consistent significant differences among groups in anthropometric outcomes. CONCLUSIONS: FBFs reformulated with sorghum, cowpea, corn, and soy significantly improved anemia and vitamin A deficiency ORs compared with week 0 and with no intervention. Although newly formulated FBFs did not significantly improve vitamin A deficiency or anemia compared with CSB+, CSB+ was the only FBF not to significantly improve these outcomes over the study duration. Our findings suggest that newly formulated sorghum- and cowpea-based FBFs are equally efficacious in improving these micronutrient outcomes. However, further FBF refinement is warranted. This trial was registered at clinicaltrials.gov as NCT02847962.

Salivary Cystatin SN Binds to Phytic Acid In Vitro and Is a Predictor of Nonheme Iron Bioavailability with Phytic Acid Supplementation in a Proof of Concept Pilot Study.

BACKGROUND: Acute phytic acid intake has been found to decrease iron bioavailability; however, repeated phytic acid consumption leads to iron absorption adaptation. Salivary proline-rich proteins (PRPs) have been shown to inhibit iron chelation to tannins and may mediate similar iron absorption adaptation with phytic acid intake. OBJECTIVES: The objectives of this study were to determine whether salivary proteins bind to phytic acid in vitro, and to explore a proof of concept in a pilot study that examined the impact of 4-wk, daily phytic acid supplementation on individuals' iron status, bioavailability, and salivary PRP concentrations. METHODS: High-performance liquid chromatography (HPLC) and matrix-assisted laser desorption/ionization-time of flight were used to characterize in vitro salivary protein-phytic acid interactions. Nonanemic women (n = 7) consumed 350 mg phytic acid supplements 3 times daily for 4 wk, and meal challenges were employed to determine iron bioavailability, iron status, and salivary protein concentrations before and after supplementation periods. Enzyme-linked immunosorbent assay (ELISA) analysis of purified protein fractions and participant saliva identified proteins bound to phytic acid. RESULTS: In vitro salivary protein-phytic acid interaction identified cystatin SN, a non-proline rich salivary protein, as the specific bound protein to phytic acid. Iron bioavailability (P = 0.32), hemoglobin (P = 0.72), and serum ferritin (P = 0.08) concentrations were not reduced from week 0 to week 4 after phytic acid supplementation. Basic PRPs and cystatin SN concentrations were positively correlated with iron bioavailability at week 4. CONCLUSIONS: Overall, results suggest that phytic acid binds to the non-PRP cystatin SN and that salivary protein production may improve iron bioavailability with phytic acid consumption.

The Impact of Tannin Consumption on Iron Bioavailability and Status: A Narrative Review.

Iron deficiency remains a global health issue, and antinutritional factors, such as tannins, are often cited as contributors to the high prevalence of deficiency. Despite this, tannin-rich diets may have potential beneficial cardiovascular and cancer-fighting properties because of the antioxidant activity of tannins. Furthermore, epidemiologic studies and long-term trials involving participants who consumed diets rich in antinutritional factors, particularly tannins, conflict with single-meal bioavailability studies. The purpose of this narrative review is to determine the effect of tannins on iron bioavailability and status and establish whether adaptation to tannins reduces the antinutritional effects of tannins over time. We also aimed to compare tannins used in iron studies. Common themes related to iron bioavailability and iron status with tannin consumption were collected and collated for summary and synthesis based on models and subjects used. Overall, there was dissonance between iron bioavailability and status in studies. Single-meal studies with hydrolyzable and oligomeric catechin and epicatechin tannins (tea and tannic acid) generally support reductions in bioavailability related to tannin consumption but not consumption of condensed tannin, which are more commonly found in food. Long-term animal model, epidemiologic, and multimeal studies generally do not support changes in iron status related to tannin intake. Studies suggest that long-term tannin consumption may impact iron status in a different manner than single-meal studies or bioavailability iron models predict. Furthermore, iron bioavailability studies that use condensed tannins, which are more commonly consumed, may better predict mealtime iron bioavailability. More research is needed to develop representative antinutritional iron studies and investigate mechanisms underlying the adaptation to tannins and other antinutritional factors that occur over time.

Salivary proline-rich protein may reduce tannin-iron chelation: a systematic narrative review.

BACKGROUND: Tannins are often cited for antinutritional effects, including chelation of non-heme iron. Despite this, studies exploring non-heme iron bioavailability inhibition with long-term consumption have reported mixed results. Salivary proline-rich proteins (PRPs) may mediate tannin-antinutritional effects on non-heme iron bioavailability. AIM: To review evidence regarding biochemical binding mechanisms and affinity states between PRPs and tannins, as well as effects of PRPs on non-heme iron bioavailability with tannin consumption in vivo. METHODS: Narrative systematic review and meta-analysis. Common themes in biochemical modeling and affinity studies were collated for summary and synthesis; data were extracted from in vivo experiments for meta-analysis. RESULTS: Thirty-two studies were included in analysis. Common themes that positively influenced tannin-PRP binding included specificity of tannin-PRP binding, PRP and tannin stereochemistry. Hydrolyzable tannins have different affinities than condensed tannins when binding to PRPs. In vivo, hepatic iron stores and non-heme iron absorption are not significantly affected by tannin consumption (d = -0.64-1.84; -2.7-0.13 respectively), and PRP expression may increase non-heme iron bioavailability with tannin consumption. CONCLUSIONS: In vitro modeling suggests that tannins favor PRP binding over iron chelation throughout digestion. Hydrolyzable tannins are not representative of tannin impact on non-heme iron bioavailability in food tannins because of their unique structural properties and PRP affinities. With tannin consumption, PRP production is increased, and may be an initial line of defense against tannin-non-heme iron chelation in vivo. More research is needed to compare competitive binding of tannin-PRP to tannin-non-heme iron complexes, and elucidate PRPs' role in adaption to non-heme iron bioavailability in vivo.

Long-Term Dose-Response Condensed Tannin Supplementation Does Not Affect Iron Status or Bioavailability.

Background: Repeated phytic acid consumption leads to iron absorption adaptation but, to the best of our knowledge, the impact of repeated tannin consumption has not yet been established. Salivary proline-rich proteins (PRPs) may improve iron absorption by precipitating tannins. Objectives: This study aimed to determine the effect of long-term, dose-response condensed tannin supplementation on iron bioavailability and status and to assess the effect of salivary proteins on iron bioavailability during prolonged condensed tannin consumption. A secondary objective was to assess astringency as a potential marker for adaptation to tannins and iron bioavailability. Methods: Eleven nonanemic women were enrolled in a double-blind 3-dose crossover trial. Three (1.5, 0.25, or 0.03 g) condensed tannin supplements were consumed 3 times/d for 4 wk in random order, with 2-wk washouts in between. Meal challenges were employed before and after supplementation to assess iron bioavailability, iron status, salivary PRP changes, and astringency. Results: Tannin supplementation in any dose did not change iron bioavailability at any dose (P > 0.82) from weeks 0 to 4. Hemoglobin (P = 0.126) and serum ferritin (P = 0.83) were unchanged by tannin dose from weeks 0 to 4. There were significant correlations among tannin supplementation and iron bioavailability, basic proline-rich proteins (bPRPs) (r = 0.366, P = 0.003), and cystatin production (r = 0.27, P = 0.03). Astringency ratings did not change significantly within or between tannin doses (P > 0.126), but there were negative relations among bPRP (r < -0.32, P < 0.21), cystatin production (r < -0.2, P < 0.28), and astringency ratings. Conclusions: Condensed tannin consumption did not affect iron bioavailability or status regardless of the supplementation period in premenopausal nonanemic women. Correlation analyses suggest that bPRPs and cystatins are associated with improved iron bioavailability and that lower ratings of astringency may predict improved iron absorption with repeated tannin consumption.

Newly formulated, protein quality-enhanced, extruded sorghum-, cowpea-, corn-, soya-, sugar- and oil-containing fortified-blended foods lead to adequate vitamin A and iron outcomes and improved growth compared with non-extruded CSB+ in rats.

Corn and soyabean micronutrient-fortified-blended foods (FBF) are commonly used for food aid. Sorghum and cowpeas have been suggested as alternative commodities because they are drought tolerant, can be grown in many localities, and are not genetically modified. Change in formulation of blends may improve protein quality, vitamin A and Fe availability of FBF. The primary objective of this study was to compare protein efficiency, Fe and vitamin A availability of newly formulated extruded sorghum-, cowpea-, soya- and corn-based FBF, along with a current, non-extruded United States Agency for International Development (USAID) corn and soya blend FBF (CSB+). A second objective was to compare protein efficiency of whey protein concentrate (WPC) and soya protein isolate (SPI) containing FBF to determine whether WPC inclusion improved outcomes. Eight groups of growing rats (n 10) consumed two white and one red sorghum-cowpea (WSC1 + WPC, WSC2 + WPC, RSC + WPC), white sorghum-soya (WSS + WPC) and corn-soya (CSB14 + WPC) extruded WPC-containing FBF, an extruded white sorghum-cowpea with SPI (WSC1 + SPI), non-extruded CSB+, and American Institute of Nutrition (AIN)-93G, a weanling rat diet, for 4 weeks. There were no significant differences in protein efficiency, Fe or vitamin A outcomes between WPC FBF groups. The CSB+ group consumed significantly less food, gained significantly less weight, and had significantly lower energy efficiency, protein efficiency and length, compared with all other groups. Compared with WSC1 + WPC, the WSC1 + SPI FBF group had significantly lower energy efficiency, protein efficiency and weight gain. These results suggest that a variety of commodities can be used in the formulation of FBF, and that newly formulated extruded FBF are of better nutritional quality than non-extruded CSB+.

The MFFAPP Tanzania Efficacy Study Protocol: Newly Formulated, Extruded, Fortified Blended Foods for Food Aid.

Fortified blended foods (FBFs) are micronutrient-fortified blends of milled cereals and pulses that represent the most commonly distributed micronutrient-fortified food aid. FBFs have been criticized due to lack of efficacy in treating undernutrition, and it has also been suggested that alternative commodities, such as sorghum and cowpea, be investigated instead of corn and soybean. The Micronutrient Fortified Food Aid Pilot Project (MFFAPP) Tanzania efficacy study was the culmination of economic, processing, sensory, and nutrition FBF research and development. MFFAPP Tanzania was a 20-wk, partially randomized cluster design conducted between February and July 2016 that enrolled children aged 6-53 mo in the Mara region of Tanzania with weight-for-height z scores >-3 and hemoglobin concentrations <10.3 mg/dL. The intervention was complementary feeding of newly formulated, extruded FBFs (white sorghum cowpea variety 1, white sorghum-cowpea variety 2, red sorghum-cowpea, white sorghum-soy blend, and corn-soy blend 14) compared with Corn Soy Blend Plus (CSB+), a current US Agency for International Development-distributed corn-soy blend, and a no-FBF-receiving control. Screened participants (n = 2050) were stratified by age group (6-23 and 24-53 mo) and allocated to 1 of 7 FBF clusters provided biweekly. Biochemical and anthropometric data were measured every 10 wk at weeks 0, 10, and 20. The primary objectives of this study were to determine whether newly formulated, extruded corn-, soy-, sorghum-, and cowpea-based FBFs result in equivalent vitamin A or iron outcomes compared with CSB+. Changes in anthropometric outcomes were also examined. Results from the MFFAPP Tanzania Efficacy Study will inform food aid producers and distributers about whether extruded sorghum- and cowpea-based FBFs are viable options for improving the health of the undernourished. This trial was registered at clinicaltrials.gov as NCT02847962.