Lysine Fortification: Past, Present, and Future

Genomic prediction reveals unexplored variation in grain protein and lysine content across a vast winter wheat genebank collection

Globally, wheat (Triticum aestivum L.) is a major source of proteins in human nutrition despite its unbalanced amino acid composition. The low lysine content in the protein fraction of wheat can lead to protein-energy-malnutrition prominently in developing countries. A promising strategy to overcome this problem is to breed varieties which combine high protein content with high lysine content. Nevertheless, this requires the incorporation of yet undefined donor genotypes into pre-breeding programs. Genebank collections are suspected to harbor the needed genetic diversity. In the 1970s, a large-scale screening of protein traits was conducted for the wheat genebank collection in Gatersleben; however, this data has been poorly mined so far. In the present study, a large historical dataset on protein content and lysine content of 4,971 accessions was curated, strictly corrected for outliers as well as for unreplicated data and consolidated as the corresponding adjusted entry means. Four genomic prediction approaches were compared based on the ability to accurately predict the traits of interest. High-quality phenotypic data of 558 accessions was leveraged by engaging the best performing prediction model, namely EG-BLUP. Finally, this publication incorporates predicted phenotypes of 7,651 accessions of the winter wheat collection. Five accessions were proposed as donor genotypes due to the combination of outstanding high protein content as well as lysine content. Further investigation of the passport data suggested an association of the adjusted lysine content with the elevation of the collecting site. This publicly available information can facilitate future pre-breeding activities.

Strategy for improved characterization of human metabolic phenotypes using a COmbined Multi-block Principal components Analysis with Statistical Spectroscopy (COMPASS)

MOTIVATION

Large-scale population omics data can provide insight into associations between gene-environment interactions and disease. However, existing dimension reduction modelling techniques are often inefficient for extracting detailed information from these complex datasets.

RESULTS

Here, we present an interactive software pipeline for exploratory analyses of population-based nuclear magnetic resonance spectral data using a COmbined Multi-block Principal components Analysis with Statistical Spectroscopy (COMPASS) within the R-library hastaLaVista framework. Principal component analysis models are generated for a sequential series of spectral regions (blocks) to provide more granular detail defining sub-populations within the dataset. Molecular identification of key differentiating signals is subsequently achieved by implementing Statistical TOtal Correlation SpectroscopY on the full spectral data to define feature patterns. Finally, the distributions of cross-correlation of the reference patterns across the spectral dataset are used to provide population statistics for identifying underlying features arising from drug intake, latent diseases and diet. The COMPASS method thus provides an efficient semi-automated approach for screening population datasets.

AVAILABILITY AND IMPLEMENTATION

Source code is available at https://github.com/cheminfo/COMPASS.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Legume dreams: The contested futures of sustainable plant-based food systems in Europe

With the intensification of agriculture, the simplification of crop rotations, and the rise in demand for meat, dairy and cereal products, legume production and consumption are at an historic low in Europe. But as the environmental consequences of agriculture (biodiversity loss, high greenhouse gas emissions, water pollution) and the health outcomes of modern diets (heart disease, cancer, diabetes, obesity) become better known, so great and varied hopes are being expressed about the future role of legumes in the food system. This paper catalogues and scrutinises these hopes, mapping the promissory narratives now orbiting around legumes. It identifies six food futures, each of which is made possible through the greater use of legumes in various production, processing, marketing and consumption contexts. These promissory narratives are theorised as contrasting responses to three major areas of contestation in the food systems literature. Namely i) the sustainability of livestock management, ii) the role of technology in different visions of the 'good diet', and iii) the merits of different models for how to make agricultural management more sustainable. It identifies the promiscuity of legumes - in terms of the range of food futures they permit - before distilling three points of consensus amongst advocates of the potential of legumes. These points of consensus relate to their nitrogen fixing capacity, their high protein content, and their long-standing historical role in the context of European food and farming. This map of legume dreams serves to guide deliberations amongst researchers, policymakers and industry stakeholders about the futures of plant-based food in Europe.

Role of novel protein sources in sustainably meeting future global requirements

Global population growth, increased life expectancy and climate change are all impacting world's food systems. In industrialised countries, many individuals are consuming significantly more protein than needed to maintain health, with the majority being obtained from animal products, including meat, dairy, fish and other aquatic animals. Current animal production systems are responsible for a large proportion of land and fresh-water use, and directly contributing to climate change through the production of greenhouse gases. Overall, approximately 60% of the global protein produced is used for animal and fish feed. Concerns about their impact on both human, and planetary health, have led to calls to dramatically curb our consumption of animal products. Underutilised plants, insects and single-cell organisms are all actively being considered as alternative protein sources. Each present challenges that need to be met before they can become economically viable and safe alternatives for food or feed. Many plant species contain anti-nutritional factors that impair the digestion and absorption of protein and micronutrients. Insects represent a potentially rich source of high-quality protein although, questions remain relating to digestibility, allergenicity and biosecurity. Algae, fungi and bacteria are also a rich source of protein and there is growing interest in the development of 'cultured meat' using stem cell technology. For the foreseeable future, it appears likely that the 'protein-economy' will remain mixed. The present paper reviews progress and future opportunities in the development of novel protein sources as food and animal feed.

Low Protein Diets and Plant-Based Low Protein Diets: Do They Meet Protein Requirements of Patients with Chronic Kidney Disease?

A low protein diet (LPD) has historically been used to delay uremic symptoms and decrease nitrogen (N)-derived catabolic products in patients with chronic kidney disease (CKD). In recent years it has become evident that nutritional intervention is a necessary approach to prevent wasting and reduce CKD complications and disease progression. While a 0.6 g/kg, high biological value protein-based LPD has been used for years, recent observational studies suggest that plant-derived LPDs are a better approach to nutritional treatment of CKD. However, plant proteins are less anabolic than animal proteins and amino acids contained in plant proteins may be in part oxidized; thus, they may not completely be used for protein synthesis. In this review, we evaluate the role of LPDs and plant-based LPDs on maintaining skeletal muscle mass in patients with CKD and examine different nutritional approaches for improving the anabolic properties of plant proteins when used in protein-restricted diets.

Bioavailable Lysine, Assessed in Healthy Young Men Using Indicator Amino Acid Oxidation, is Greater when Cooked Millet and Stewed Canadian Lentils are Combined

BACKGROUND

Pearl millet is the chief source of energy in the diet in some developing regions, but has a limited amount of indispensable amino acid lysine. Complementation with pulses like lentils can improve the protein quality of millet diets, but the knowledge of lysine bioavailability (BA) in millet and lentils is lacking.

OBJECTIVES

The study objectives were to determine the BA of lysine in millet and lentils separately and to assess the effect of complementation of millet and lentils in a mixed meal format.

METHODS

We studied 9 healthy young men (≤30 y; BMI <25) in a repeated-measure design using the indicator amino acid oxidation (IAAO) method, with L-[1-13C] phenylalanine as the indicator. Each subject completed 7 or 8 experiments in random order. On the reference diet, subjects received 4 graded levels of L-lysine (5, 8, 12, and 15 mg·kg-1.d-1) from a crystalline amino acid mixture patterned after egg protein; on the test diets, they received 3 levels of lysine (10, 12, and 15 mg·kg-1.d-1) from either steamed millet or stewed lentils; and on the complementation diet, they received 1 level of lysine from a mixed meal of steamed millet and stewed lentils. The BA of lysine and the effect of complementation were assessed by comparing the IAAO responses to the test diets and the complementation diet with the IAAO response to L-lysine intakes in the reference protein, using the slope ratio method.

RESULTS

The BA of lysine was 97% from millet and 80% from lentils. Complementation of steamed millet with stewed lentils decreased the oxidation of L-[1-13C] phenylalanine by 27% (P < 0.05), signifying improved quality of the combined millet and lentil protein.

CONCLUSIONS

Lysine has high BA but is still limiting in steamed pearl millet. Complementation with lentils in a 2:1 ratio is recommended to meet the lysine and protein requirements for adult men consuming a millet-based diet. This trial was registered at clinicaltrials.gov as NCT03674736 and NCT03339167.

Proposals for Upper Limits of Safe Intake for Methionine, Histidine, and Lysine in Healthy Humans

Based on research presented during the 10th Amino Acid Assessment Workshop, no observed adverse effect levels (NOAELs) for supplemental methionine at 46 mg/(kg·d) (∼3.2 g/d), for supplemental histidine at 8.0 g/d, and for supplemental lysine at 6.0 g/d have been proposed. These NOAELs are relevant to healthy adults and are applicable only to high-purity amino acids administered in fortified foods or dietary supplements. Because individuals are exposed to the above supplemental amino acids in the context of complex combinations of essential amino acids or individually in dietary supplements for various physiologic benefits, such as body fat reduction, skin conditioning, mental energy increase, or herpes simplex treatments, the above safety recommendations will make an important contribution to regulatory and nutritional practices.

Separating the Wheat from the Chaff: Nutritional Value of Plant Proteins and Their Potential Contribution to Human Health

The quality and nutritional value of dietary proteins are determined by the quantity, digestibility and bioavailability of essential amino acids (EAA), which play a critical role in human growth, longevity and metabolic health. Plant-source protein is often deficient in one or more EAAs (e.g., branched-chain amino acids, lysine, methionine and/or tryptophan) and, in its natural form, is less digestible than animal-source protein. Nevertheless, dietary intake of plant-source protein has been promoted because of its potential health benefits, lower cost of production and lower environmental impact compared to animal-source protein. Implementation of dietary strategies that improve both human and planetary health are of critical importance and subject to growing interest from researchers and consumers. Therefore, in this review we analyse current plant protein intake patterns and discuss possible countermeasures that can enhance plant protein nutrition, examples include: (1) combining different plant proteins with complementary EAA profiles; (2) identification and commercial cultivation of new and novel high-quality plant proteins; (3) industrial and domestic processing methods; and (4) genome-editing techniques.

Sorghum Grain: From Genotype, Nutrition, and Phenolic Profile to Its Health Benefits and Food Applications

Globally, sorghum is one of the most important but least utilized staple crops. Sorghum grain is a rich source of nutrients and health-beneficial phenolic compounds. The phenolic profile of sorghum is exceptionally unique and more abundant and diverse than other common cereal grains. The phenolic compounds in sorghum are mainly composed of phenolic acids, 3-deoxyanthocyanidins, and condensed tannins. Studies have shown that sorghum phenolic compounds have potent antioxidant activity in vitro, and consumption of sorghum whole grain may improve gut health and reduce the risks of chronic diseases. Recently, sorghum grain has been used to develop functional foods and beverages, and as an ingredient incorporated into other foods. Moreover, the phenolic compounds, 3-deoxyanthocyanidins, and condensed tannins can be isolated and used as promising natural multifunctional additives in broad food applications. The objective of this review is to provide a comprehensive understanding of nutrition and phenolic compounds derived from sorghum and their related health effects, and demonstrate the potential for incorporation of sorghum in food systems as a functional component and food additive to improve food quality, safety, and health functions.

Safety assessment of L-lysine oral intake: a systematic review

Currently, the use of amino acids in supplements and functional foods is increasing globally. However, there are no guidelines for the upper limit of ingestion for the safe use of these amino acids. Safety evaluation of chemical substances is generally performed through non-clinical and clinical studies. However, amino acids that have these safety data are limited. Therefore, we used a systematic review approach for evaluating the safety of amino acids. In the present study, we evaluated the safety of L-lysine added to an ordinary diet in humans. Using PubMed, Cochrane Library, Ichushi Web, and EBSCOhost as search databases, we comprehensively searched human studies on oral ingestion of L-lysine. Ultimately, 71 studies were selected for evaluation. Of these, 12 studies were of relatively high quality with Jadad scores ≥ 3. The dose range of L-lysine in the selected studies was 16.8-17,500 mg/day, and the range of dosing period was 1-1095 days. The observed adverse events were mainly subjective symptoms related to the gastrointestinal tract such as nausea, stomachache, and diarrhea. The provisional no-observed-adverse-effect level obtained based on these gastrointestinal symptoms was 6000 mg/person/day. Integrated analysis of the risk for developing gastrointestinal symptoms revealed that the risk ratio was 1.02 (95% CI, 0.96-1.07; p = 0.49); thus, no significant increase was observed. (UMIN000028914).

A Novel Concept of Amino Acid Supplementation to Improve the Growth of Young Malnourished Male Rats

BACKGROUNDS/AIMS

This study was aimed at understanding the relationship between plasma amino acids and protein malnutrition and at determining whether amino acid supplementation associated with malnutrition and growth improves linear growth in growing rats.

METHODS

Body length and plasma amino acids were measured in young male rats that were fed the following diet for 3 weeks, mimicking a low and imbalanced protein diets based on maize, a major staple consumed in developing countries: a 70% calorically restricted cornmeal-based diet (C), C + micronutrients (CM), CM + casein (CMC), CM + soy protein (CMS) or CMS + 0.3% lysine.

RESULTS

A correlation analysis of linear growth and plasma amino acids indicated that lysine, tryptophan, branched-chain amino acids, methionine, and phenylalanine significantly correlated with body length. Supplementation with these 5 amino acids (AA1) significantly improved the body length in rats compared to CMC treatment whereas, nitrogen-balanced amino acid supplemented controls (AA2) did not (CM +1.2 ± 0.2, CMC +2.7 ± 0.3, CMS +2.1 ± 0.3, AA1 +2.8 ± 0.2, and AA2 +2.5 ± 0.3 cm).

CONCLUSION

With securing proper amino acid balance, supplementing growth-related amino acids is more effective in improving linear growth in malnourished growing male rats. Analysis of the correlation between plasma amino acids and growth represents a powerful tool to determine candidate amino acids for supplementation to prevent malnutrition. This technology is adaptable to children in developing countries.

Effect of lysine supplementation on hypertensive men and women in selected peri-urban community in Ghana

Background

Lysine is one of the essential amino acids and in cereal based diets it is known to be the most limiting and therefore determines the quality of dietary protein in such diets. This study investigated the effect of lysine supplementation on blood pressure of hypertensive adults in selected peri-urban community in Accra, Ghana.

Methods

The study was a randomized double-blind controlled study made up of adults men and women assigned to a lysine supplemented group and a placebo-supplemented (control) group. The subjects aged between 18 – 45 years and totaling 180.

Results

Total of 50 (28%) of the participating were hypertensive defined as Systolic Blood Pressure (SBP) ≥140 mmHg. The mean SBP of lysine-supplemented group significantly dropped from 146.11 ± 11.92 to 128.95 ± 10.44 mmHg (p = 0.02). That of women also dropped from 144.12 ± 10.41 to 132.28 ± 10.69 mmHg, (p = 0.06 while the control group had there SBP remained fairly constant after 112 days of intervention with changes in men from 145.79 ± 12.56 to 142.79 ± 11.07 mmHg (p = 0.32) and women in the control had very little drop from 145.15 ± 14.79 to 145.00 ± 17.93 mmHg (p = 0.96).

Conclusion

Lysine supplementation resulted in normalization/reduction of blood pressure of hypertensive subjects who have suboptimal lysine intake.

Biofortification of rice with lysine using endogenous histones

Rice is the most consumed cereal grain in the world, but deficient in the essential amino acid lysine. Therefore, people in developing countries with limited food diversity who rely on rice as their major food source may suffer from malnutrition. Biofortification of stable crops by genetic engineering provides a fast and sustainable method to solve this problem. In this study, two endogenous rice lysine-rich histone proteins, RLRH1 and RLRH2, were over-expressed in rice seeds to achieve lysine biofortification. Their protein sequences passed an allergic sequence-based homology test. Their accumulations in rice seeds were raised to a moderate level by the use of a modified rice glutelin 1 promoter with lowered expression strength to avoid the occurrence of physiological abnormalities like unfolded protein response. The expressed proteins were further targeted to protein storage vacuoles for stable storage using a glutelin 1 signal peptide. The lysine content in the transgenic rice seeds was enhanced by up to 35 %, while other essential amino acids remained balanced, meeting the nutritional standards of the World Health Organization. No obvious unfolded protein response was detected. Different degrees of chalkiness, however, were detected in the transgenic seeds, and were positively correlated with both the levels of accumulated protein and lysine enhancement. This study offered a solution to the lysine deficiency in rice, while at the same time addressing concerns about food safety and physiological abnormalities in biofortified crops.

Consumer acceptance of quality protein maize (QPM) in East Africa

BACKGROUND

Undernutrition in sub-Saharan Africa remains problematic, and quality protein maize (QPM) can benefit populations whose diets are heavily based on maize and who are consequently at risk for inadequate intakes of quality protein. However, changes in the chemical composition of QPM may affect its sensory characteristics and, hence, acceptance. Acceptance tests were therefore conducted to evaluate QPM varieties in three East African countries using central location tests with one or two varieties in each country, using the most popular preparations: ugali (Tanzania), githeri (Kenya) and injera (Ethiopia). In total, 281 urban and rural consumers of both sexes and varying levels of education evaluated the products on standard sensory criteria: appearance, aroma, texture, taste and overall, using a Likert scale.

RESULTS

The results show that African consumers can differentiate QPM products from their conventional counterparts, indicating that the QPM trait results in distinguishable sensory changes. Analysis by ordinal mixed regression models showed that consumers found QPM acceptable and even preferable to conventional maize.

CONCLUSION

The sensory characteristics of QPM are therefore no impediment to its adoption; on the contrary, when coupled with good agronomic performance, they may help its utilization, leading to a positive impact in nutritionally vulnerable populations.

Reduced-gliadin wheat bread: an alternative to the gluten-free diet for consumers suffering gluten-related pathologies

Wheat flour cannot be tolerated by those who suffer allergies to gluten. Human pathologies associated with grain proteins have increased worldwide in recent years, and the only effective treatment available is a lifelong gluten-free diet, which is complicated to follow and detrimental to gut health. This manuscript describes the development of wheat bread potentially suitable for celiac patients and other gluten-intolerant individuals. We have made bread using wheat flour with very low content of the specific gluten proteins (near gliadin-free) that are the causal agents for pathologies such as celiac disease. Loaves were compared with normal wheat breads and rice bread. Organoleptic, nutritional, and immunotoxic properties were studied. The reduced-gliadin breads showed baking and sensory properties, and overall acceptance, similar to those of normal flour, but with up to 97% lower gliadin content. Moreover, the low-gliadin flour has improved nutritional properties since its lysine content is significantly higher than that of normal flour. Conservative estimates indicate that celiac patients could safely consume 67 grams of bread per day that is made with low-gliadin flour. However, additional studies, such as feeding trials with gluten-intolerant patients, are still needed in order to determine whether or not the product can be consumed by the general celiac population, as well as the actual tolerated amount that can be safely ingested. The results presented here offer a major opportunity to improve the quality of life for millions of sufferers of gluten intolerance throughout the world.

Assessment of protein adequacy in developing countries: quality matters

Dietary protein and amino acid requirement recommendations for normal "healthy" children and adults have varied considerably with 2007 FAO/WHO protein requirement estimates for children lower, but dietary essential AA requirements for adults more than doubled. Requirement estimates as presented do not account for common living conditions, which are prevalent in developing countries such as energy deficit, infection burden and added functional demands for protein and AAs. This study examined the effect of adjusting total dietary protein for quality and digestibility (PDCAAS) and of correcting current protein and AA requirements for the effect of infection and a mild energy deficit to estimate utilizable protein (total protein corrected for biological value and digestibility) and the risk/prevalence of protein inadequacy. The relationship between utilizable protein/prevalence of protein inadequacy and stunting across regions and countries was examined. Data sources (n = 116 countries) included FAO FBS (food supply), UNICEF (stunting prevalence), UNDP (GDP) and UNSTATS (IMR) and USDA nutrient tables. Statistical analyses included Pearson correlations, paired-sample/non-parametric t-tests and linear regression. Statistically significant differences were observed in risk/prevalence estimates of protein inadequacy using total protein and the current protein requirements versus utilizable protein and the adjusted protein requirements for all regions (p < 0·05). Total protein, utilizable protein, GDP per capita and total energy were each highly correlated with the prevalence of stunting. Energy, protein and utilizable protein availability were independently and negatively associated with stunting (p < 0·001), explaining 41 %, 34 % and 40 % of variation respectively. Controlling for energy, total protein was not a statistically significant factor but utilizable protein remained significant explaining~45 % of the variance (p = 0·017). Dietary utilizable protein provides a better index of population impact of risk/prevalence of protein inadequacy than crude protein intake. We conclude that the increased demand for protein due to infections and mild to moderate energy deficits, should be appropriately considered in assessing needs of populations where those conditions still prevail.

Effect of lysine, vitamin B(6), and carnitine supplementation on the lipid profile of male patients with hypertriglyceridemia: a 12-week, open-label, randomized, placebo-controlled trial

BACKGROUND

Fat metabolism is known to be altered in hypertriglyceridemia. Fat oxidation requires carnitine, which can be obtained either from the diet (animal or dairy products) or through synthesis in the body using both lysine and vitamin B(6).

OBJECTIVE

The goal of this study was to investigate the effect of lysine, vitamin B(6), and carnitine supplementation on both glycemia and the lipid profiles, specifically triglyceride (TG) levels, in men with hypertriglyceridemia.

METHODS

This 12-week, randomized, placebo-controlled clinical trial was conducted at a Lebanese medical center. A total of 85 hypertriglyceridemic (TG> 150 mg/dL) male patients were randomized to 1 of 5 groups and given supplements of lysine (1 g/d), vitamin B(6) (50 mg/d), lysine (1 g/d) + vitamin B(6) (50 mg/d), carnitine (1 g/d), or placebo for 12 weeks. The lipid profile (TG, total cholesterol, LDL-C, and HDL-C) and fasting plasma glucose levels were assessed at baseline and at 6 and 12 weeks.

RESULTS

Adults (∼50 years) Lebanese males from a low socioeconomic status in Beirut were given the appropriate supplements. Vitamin B(6) supplementation was associated with a significant reduction in total cholesterol and HDL-C of ∼10%. In addition, plasma TG was reduced by 36.6 mg/dL at 6 weeks, whereas levels in the placebo group increased by 18 mg/dL; this difference failed to reach statistical significance. No major changes in the lipid profile were observed in the lysine and carnitine groups or when lysine was added to vitamin B(6).

CONCLUSION

Vitamin B(6) supplementation in these male patients with hypertriglyceridemia reduced plasma total cholesterol and HDL-C concentrations.

Effect of lysine supplementation on health and morbidity in subjects belonging to poor peri-urban households in Accra, Ghana

BACKGROUND

Lysine affects diarrhea and anxiety via effects on serotonin receptors, enhanced intestinal repair, and sodium chloride-dependent opioid peptide transport.

OBJECTIVE

The objective was to investigate the effects of lysine supplementation on morbidity, growth, and anxiety in children and adults of peri-urban areas of Accra, Ghana.

DESIGN

In a double-blind randomized trial, the effect of lysine supplementation (1 g lysine/d) compared with that of placebo was examined in 2 groups of men, women, and children (n = 271). Primary outcomes included diarrheal and respiratory morbidity, growth, and anxiety and complement C3, C-reactive protein, serum cortisol, transferrin, and ferritin values. Independent-sample t tests, odds ratios, generalized estimating equations, 4-parameter sinusoid regression, and generalized linear models were used.

RESULTS

Thirty percent of men, 50% of women, and 15% of children were at risk of lysine inadequacy. Supplementation in children reduced diarrheal episodes [19 lysine, 35 placebo; odds ratio (OR): 0.52; 95% CI: 0.29, 0.92; P = 0.046] and the total number of days ill (21 lysine, 47 placebo; OR: 0.44; 95% CI: 0.26, 0.74; P = 0.034). Mean days ill per child per week (0.058 ± 0.039 lysine, 0.132 ± 0.063 placebo; P = 0.017) were negatively associated with weight gain with control for baseline weight and study group (P = 0.04). Men had fewer coryza episodes (23 lysine, 39 placebo; OR: 0.60; 95% CI: 0.36, 1.01; P = 0.05), total number of days ill (lysine: 130; placebo: 266; OR: 0.51; 95% CI: 0.28, 0.93; P = 0.03), and mean days ill per person per week (lysine: 0.21 ± 0.23; placebo: 0.41 ± 0.35; P = 0.04). Serum ferritin (P = 0.045) and C-reactive protein (P = 0.018) decreased in lysine-supplemented women but increased in placebo-supplemented women.

CONCLUSION

Lysine supplementation reduced diarrheal morbidity in children and respiratory morbidity in men in Ghana.

The Effectiveness of Quality Protein Maize in Improving the Nutritional Status of Young Children in the Ethiopian Highlands

Background

Undernutrition is a persistent problem in Africa, especially in rural areas where the poor largely depend on staples and have limited access to a diverse diet. Quality protein maize (QPM) consists of maize varieties biofortified with increased lysine and tryptophan levels. Several studies in controlled settings have indicated the positive impact of QPM on the nutritional status of children.

Objective

Two 1-year, randomized, controlled studies were undertaken to measure the effect of QPM on the nutritional status of children consuming typical maize-based diets when QPM was cultivated by their households in the western Ethiopian highlands.

Methods

The first study used a cluster-randomized design with 151 children aged 5 to 29 months; the second study used a completely randomized design with 211 children aged 7 to 56 months. In both studies, half of the households were provided with QPM seed and the other half with seed of an improved conventional maize variety.

Results

Undernutrition was pervasive, and maize was the dominant food in the children's complementary diets. In the first study, a positive effect of QPM was observed for weight but not height, with children in the QPM group recovering from a drop in weight-for-height. In the second study, children consuming conventional maize progressively faltered in their growth, whereas children consuming QPM did not change significantly in height-for-age and had a marginal increase in weight-for-age.

Conclusions

These studies indicate that in major maize-producing and -consuming areas of Africa, home cultivation and use of QPM in children's diets could reduce or prevent growth faltering and may in some cases support catch-up growth in weight.

Lysine requirement in parenterally fed postsurgical human neonates

BACKGROUND

The lysine requirement of human neonates receiving parenteral nutrition (PN) has not been determined experimentally.

OBJECTIVE

The objective was to determine the parenteral lysine requirement for human neonates by using the minimally invasive indicator amino acid oxidation technique with l-[1-(13)C] phenylalanine as the indicator amino acid.

DESIGN

Eleven postsurgical neonates were randomly assigned to 15 lysine intakes ranging from 50 to 260 mg . kg(-1) . d(-1). Breath and urine samples were collected at baseline and at plateau for (13)CO(2) (F(13)CO(2)) and amino acid enrichment, respectively. The mean lysine requirement was determined by applying a 2-phase linear regression crossover analysis to the measured rates of F(13)CO(2) release and l-[1-(13)C]phenylalanine oxidation.

RESULTS

The mean parenteral lysine requirement determined by F(13)CO(2) release oxidation was 104.9 mg . kg(-1) . d(-1) (upper and lower CIs: 120.6 and 89.1 mg . kg(-1) . d(-1), respectively). The mean lysine parenteral requirement determined by phenylalanine oxidation was 117.6 mg . kg(-1) . d(-1) (upper and lower CIs: 157.5 and 77.6 mg . kg(-1) . d(-1), respectively). Graded intakes of lysine had no effect on phenylalanine flux.

CONCLUSION

We recommend a mean lysine requirement for the postsurgical PN-fed neonate of 104.9 mg . kg(-1) . d(-1), which is 32-43% of the lysine concentration presently found in commercial PN solutions (246-330 mg . kg(-1) . d(-1)). This trial was registered at clinicaltrials.gov as NCT00779753.

The importance of dietary protein in human health: combating protein deficiency in sub-Saharan Africa through transgenic biofortified sorghum

Child malnutrition is increasing in Africa. Protein deficiency is an important cause since protein is essential for both growth and maintenance of muscle mass. Sorghum is a major staple food in Africa on account of its hardiness as a crop. However, sorghum protein is very deficient in the indispensable amino acid lysine and on cooking has poor protein digestibility. This results in sorghum having a very low Protein Digestibility Corrected Amino Acid Score (PDCAAS). The Africa Biofortified Sorghum project, a Grand Challenges in Global Heath project, is undertaking research to biofortify sorghum in terms of protein and micronutrient quality using genetic engineering. Lysine and protein digestibility have been improved by suppression of synthesis of the kafirin storage proteins. Transgenic biofortified sorghum has double the PDCAAS of conventional sorghum. This improvement should enable a young child to meet most of its protein and energy requirements from biofortified sorghum porridge. This together with the improvement in micronutrients could provide the basis of a sustainable and broadly comprehensive solution to child malnutrition in many African countries.