International Life Sciences Institute Research Articles

Methods to Evaluate Uptake of Engineered Nanomaterials by the Alimentary Tract.

This article is one of a series of 4 that report on a task of the NanoRelease Food Additive project of the International Life Science Institute Center for Risk Science Innovation and Application to identify, evaluate, and develop methods that are needed to confidently detect, characterize, and quantify intentionally produced engineered nanomaterials (ENMs) released from food along the alimentary tract. This particular article focuses on the problem of detecting and characterizing ENMs in the various compartments of the alimentary tract after they have been ingested from dietary sources. An in depth analysis of the literature related to oral toxicity of ENMs is presented, paying particular attention to analytical methodology and sample preparation. The review includes a discussion of model systems that can be used to study oral uptake of ENMs in the absence of human toxicological data or other live-animal studies. The strengths and weaknesses of various analytical and sample preparation techniques are discussed. The article concludes with a summary of findings and a discussion of potential knowledge gaps and targets for method development in this area.

Measurement Methods to Detect, Characterize, and Quantify Engineered Nanomaterials in Foods.

This article is one of a series of 4 that reports on a task of the NanoRelease Food Additive project of the International Life Science Institute Center for Risk Science Innovation and Application to identify, evaluate, and develop methods that are needed to confidently detect, characterize, and quantify intentionally produced engineered nanomaterials (ENMs) released from food along the alimentary tract. This particular article focuses on the problem of detecting ENMs in food, paying special attention to matrix interferences and how to deal with them. In this review, an in-depth analysis of the literature related to detection of ENMs in complex matrices is presented. The literature review includes discussions of sampling methods, such as centrifugation and ENM extraction. Available analytical methods, as well as emerging methods, are also presented. The article concludes with a summary of findings and an overview of potential knowledge gaps and targets for method development in this area.

John Austin Milner, PhD (1947–2013)1,2

John Austin Milner was born on 11 June 1947 in Pine Bluff, AR, and died unexpectedly of a heart attack on 31 December 2013. He was a dear friend to so many scientists that his passing is an irreplaceable loss to the nutrition community and to all those who were fortunate enough to know him. John had a formidable capacity for work and for multitasking on many different projects while never turning away requests for help from colleagues, never failing to ask provocative questions, and always answering every single e-mail. He had a great sense of humor and a unique ability to integrate science with humanistic considerations. Although most of his own research focused on the anticancer properties of garlic and associated allyl sulfur compounds, his interests gradually expanded to bioactives of all sorts. He was an internationally respected expert in all areas of nutrition and cancer prevention, including nutrigenomics, selenium nutriture, antioxidants and health, and functional foods. For 16 y, he chaired the popular sessions on Saturday mornings sponsored by the International Life Sciences Institute (ILSI) at the Experimental Biology meetings, and he edited several of them for publication. John A. Milner (1947–2013)

Sugars and health: applying evidence mapping techniques to assess the evidence (630.10)

Objective: Evidence mapping (EM) is a novel, systematic method for describing the volume and characteristics of research in a broad field. We applied EM to evaluate the empirical evidence of the state of science on the relationships between sugars and cardiometabolic health‐related outcomes.Methods: A pre‐defined, systematic study selection process was applied to a broad Medline search (through April 2013) of the existing literature on sugars. Studies reporting cardiometabolic risk factors and/or related clinical outcomes were selected for this study. Data from the studies were extracted and deposited to a data repository. Descriptive analyses were performed.Results: Our EM included 207 studies (196 intervention and 11 cohort studies). Of the intervention studies, the most common sugar interventions were sucrose (40%) and fructose (31%), and the top two controls were glucose (14%) and starch (13%). The most studied outcomes were glycemic profiles (27%), plasma lipids (11%), and anthropometrics (7%). Studies were generally short in duration (median 26 days, ranging from <1 to 730 days). 89% were in adults and 6% were in children. The 11 cohort studies investigated 3 different sugar exposures and 9 different hard clinical outcomes.Conclusions: An extensive but heterogeneous body of evidence exists in this broad field of research. EM is a useful method for identifying “hot” research areas and research gaps. Evidence‐based methods are effective to direct future research.Grant Funding Source: This study is in part supported by International Life Science Institute North America

John A. Milner: In Memoriam (1947–2013)

![Figure][1] On December 31, 2013, the scientific community lost Dr. John A. Milner, an internationally respected scientist known for his work in human nutrition and cancer prevention. John served as Chief of National Cancer Institute's (NCI) Nutritional Science Research Group in the

Characteristics and safety assessment of intractable proteins in genetically modified crops

Genetically modified (GM) crops may contain newly expressed proteins that are described as “intractable”. Safety assessment of these proteins may require some adaptations to the current assessment procedures. Intractable proteins are defined here as those proteins with properties that make it extremely difficult or impossible with current methods to express in heterologous systems; isolate, purify, or concentrate; quantify (due to low levels); demonstrate biological activity; or prove equivalency with plant proteins. Five classes of intractable proteins are discussed here: (1) membrane proteins, (2) signaling proteins, (3) transcription factors, (4) N-glycosylated proteins, and (5) resistance proteins (R-proteins, plant pathogen recognition proteins that activate innate immune responses). While the basic tiered weight-of-evidence approach for assessing the safety of GM crops proposed by the International Life Sciences Institute (ILSI) in 2008 is applicable to intractable proteins, new or modified methods may be required. For example, the first two steps in Tier I (hazard identification) analysis, gathering of applicable history of safe use (HOSU) information and bioinformatics analysis, do not require protein isolation. The extremely low level of expression of most intractable proteins should be taken into account while assessing safety of the intractable protein in GM crops. If Tier II (hazard characterization) analyses requiring animal feeding are judged to be necessary, alternatives to feeding high doses of pure protein may be needed. These alternatives are discussed here.

Criteria for validation and selection of cognitive tests for investigating the effects of foods and nutrients

This review is an output of the International Life Sciences Institute (ILSI) Europe Marker Initiative, which aims to identify evidence-based criteria for selecting adequate measures of nutrient effects on health through comprehensive literature review. Experts in cognitive and nutrition sciences examined the applicability of these proposed criteria to the field of cognition with respect to the various cognitive domains usually assessed to reflect brain or neurological function. This review covers cognitive domains important in the assessment of neuronal integrity and function, commonly used tests and their state of validation, and the application of the measures to studies of nutrition and nutritional intervention trials. The aim is to identify domain-specific cognitive tests that are sensitive to nutrient interventions and from which guidance can be provided to aid the application of selection criteria for choosing the most suitable tests for proposed nutritional intervention studies using cognitive outcomes. The material in this review serves as a background and guidance document for nutritionists, neuropsychologists, psychiatrists, and neurologists interested in assessing mental health in terms of cognitive test performance and for scientists intending to test the effects of food or food components on cognitive function.

John A. Milner, 1947−2013: A Champion of Nutrition

The nutrition community at large has suffered a profound loss with the unexpected death of John A. Milner on December 31, 2013. Dr. Milner was chair of the International Life Science Institute's Publications Committee, which oversees Nutrition Reviews. He was an ardent supporter of the mission of the journal and always available to share new ideas and discuss ways in which emerging challenges and unmet needs in the fields of nutrition and food science could be met. As an internationally respected scientist recognized for his broad understanding and championing of the …

Fortification: new findings and implications

This article reviews the current landscape regarding food fortification in the United States; the content is based on a workshop sponsored by the North American Branch of the International Life Sciences Institute. Fortification of the food supply with vitamins and minerals is a public health strategy to enhance nutrient intakes of the population without increasing caloric intake. Many individuals in the United States would not achieve recommended micronutrient intakes without fortification of the food supply. The achievement and maintenance of a desirable level of nutritional quality in the nation's food supply is, thus, an important public health objective. While the addition of nutrients to foods can help maintain and improve the overall nutritional quality of diets, indiscriminate fortification of foods could result in overfortification or underfortification in the food supply and nutrient imbalances in the diets of individuals. Any changes in food fortification policy for micronutrients must be considered within the context of the impact they will have on all segments of the population and of food technology and safety applications and their limitations. This article discusses and evaluates the value of fortification, the success of current fortification efforts, and the future role of fortification in preventing or reversing nutrient inadequacies.

Allergic sensitization: food- and protein-related factors.

Presented here are emerging capabilities to precisely measure endogenous allergens in soybean and maize, consideration of food matrices on allergens, and proteolytic activity of allergens. Also examined are observations of global allergy surveys and the prevalence of food allergy across different locales. Allergenic potential is considered in the context of how allergens can be characterized for their biochemical features and the potential for proteins to initiate a specific immune response. Some of the limitations in performing allergen characterization studies are examined. A combination of physical traits of proteins, the molecular interaction between cells and proteins in the human body, and the uniqueness of human culture play a role in understanding and eventually predicting protein allergy potential. The impact of measuring food allergens on determining safety for novel food crops and existing allergenic foods was highlighted with the conclusion that measuring content without the context of clinically relevant thresholds adds little value to safety. These data and findings were presented at a 2012 international symposium in Prague organized by the Protein Allergenicity Technical Committee of the International Life Sciences Institute’s Health and Environmental Sciences Institute.

Sensitizing properties of proteins: executive summary.

The scope of allergy risk is diverse considering the myriad ways in which protein allergenicity is affected by physiochemical characteristics of proteins. The complexity created by the matrices of foods and the variability of the human immune system add additional challenges to understanding the relationship between sensitization potential and allergy disease. To address these and other issues, an April 2012 international symposium was held in Prague, Czech Republic, to review and discuss the state-of-the-science of sensitizing properties of protein allergens. The symposium, organized by the Protein Allergenicity Technical Committee of the International Life Sciences Institute’s Health and Environmental Sciences Institute, featured presentations on current methods, test systems, research trends, and unanswered questions in the field of protein sensitization. A diverse group of over 70 interdisciplinary scientists from academia, government, and industry participated in the symposium. Experts provided overviews on known mechanisms by which proteins in food may cause sensitization, discussed experimental models to predict protein sensitizing potential, and explored whether such experimental techniques may be applicable in regulatory settings. Three accompanying reviews address critical factors and methods for assessing allergic sensitization: 1) food-and protein-related factors; 2) host-specific factors and 3) screening methods, i.e., the ability of experimental models to predict the sensitizing potential of proteins and whether such models are applicable within regulatory settings.

Allergic sensitization: host-immune factors.

Allergic sensitization is the outcome of a complex interplay between the allergen and the host in a given environmental context. The first barrier encountered by an allergen on its way to sensitization is the mucosal epithelial layer. Allergic inflammatory diseases are accompanied by increased permeability of the epithelium, which is more susceptible to environmental triggers. Allergens and co-factors from the environment interact with innate immune receptors, such as Toll-like and protease-activated receptors on epithelial cells, stimulating them to produce cytokines that drive T-helper 2-like adaptive immunity in allergy-prone individuals. In this milieu, the next cells interacting with allergens are the dendritic cells lying just underneath the epithelium: plasmacytoid DCs, two types of conventional DCs (CD11b + and CD11b-), and monocyte-derived DCs. It is now becoming clear that CD11b+, cDCs, and moDCs are the inflammatory DCs that instruct naïve T cells to become Th2 cells. The simple paradigm of non-overlapping stable Th1 and Th2 subsets of T-helper cells is now rapidly being replaced by that of a more complex spectrum of different Th cells that together drive or control different aspects of allergic inflammation and display more plasticity in their cytokine profiles. At present, these include Th9, Th17, Th22, and Treg, in addition to Th1 and Th2. The spectrum of co-stimulatory signals coming from DCs determines which subset-characteristics will dominate. When IL-4 and/or IL-13 play a dominant role, B cells switch to IgE-production, a process that is more effective at young age. IgE-producing plasma cells have been shown to be long-lived, hiding in the bone-marrow or inflammatory tissues where they cannot easily be targeted by therapeutic intervention. Allergic sensitization is a complex interplay between the allergen in its environmental context and the tendency of the host’s innate and adaptive immune cells to be skewed towards allergic inflammation. These data and findings were presented at a 2012 international symposium in Prague organized by the Protein Allergenicity Technical Committee of the International Life Sciences Institute’s Health and Environmental Sciences Institute.

Allergic sensitization: screening methods.

Experimental in silico, in vitro, and rodent models for screening and predicting protein sensitizing potential are discussed, including whether there is evidence of new sensitizations and allergies since the introduction of genetically modified crops in 1996, the importance of linear versus conformational epitopes, and protein families that become allergens. Some common challenges for predicting protein sensitization are addressed: (a) exposure routes; (b) frequency and dose of exposure; (c) dose-response relationships; (d) role of digestion, food processing, and the food matrix; (e) role of infection; (f) role of the gut microbiota; (g) influence of the structure and physicochemical properties of the protein; and (h) the genetic background and physiology of consumers. The consensus view is that sensitization screening models are not yet validated to definitively predict the de novo sensitizing potential of a novel protein. However, they would be extremely useful in the discovery and research phases of understanding the mechanisms of food allergy development, and may prove fruitful to provide information regarding potential allergenicity risk assessment of future products on a case by case basis. These data and findings were presented at a 2012 international symposium in Prague organized by the Protein Allergenicity Technical Committee of the International Life Sciences Institute’s Health and Environmental Sciences Institute.

Research and Policy to Achieve Healthy Aging in Asia: Recommendations from an Expert Workshop

Asia has currently one of the largest concentrations of aging persons in the world. This trend is expected to continue due to increasing longevity and continued fertility reductions in its member countries. Asian countries need to start planning for these future demographic changes by formulating evidence-based policies to address aging. A workshop on healthy aging in Asia was recently organized by the International Life Sciences Institute Southeast Asia (ILSI SEA) Region in Singapore. The goal was to discuss aging-related issues in the region and identify ways to address these issues through scientific research. Policy issues that were identified include: difficulty in translating scientific findings into policy initiatives, lack of government financial resources to support agingresearch, food insecurity among Asian elderly, and diverse ethnic populations that necessitate tailored interventions to address specific health problems. Better quality of health rather than increased longevity was seen as an important goal to strive for. Health issues identified include: maintaining autonomy and independence in a developing country context, developing fitness standards for Asians, examining how Asian populations transition into disability, and identifying health pathways in developing countries, among others. Multi-disciplinary and collaborative research is the best approach to address these issues. Future actions include the establishment of a regional consortium or collaborative network to guide the research agenda that can support aging policies as well as the exploitation of existing opportunities for public-private partnerships.

Editorial introductions

Editorial introductions

Selection of appropriate tumour data sets for Benchmark Dose Modelling (BMD) and derivation of a Margin of Exposure (MoE) for substances that are genotoxic and carcinogenic: Considerations of biological relevance of tumour type, data quality and uncertainty assessment

This article addresses a number of concepts related to the selection and modelling of carcinogenicity data for the calculation of a Margin of Exposure. It follows up on the recommendations put forward by the International Life Sciences Institute – European branch in 2010 on the application of the Margin of Exposure (MoE) approach to substances in food that are genotoxic and carcinogenic. The aims are to provide practical guidance on the relevance of animal tumour data for human carcinogenic hazard assessment, appropriate selection of tumour data for Benchmark Dose Modelling, and approaches for dealing with the uncertainty associated with the selection of data for modelling and, consequently, the derived Point of Departure (PoD) used to calculate the MoE. Although the concepts outlined in this article are interrelated, the background expertise needed to address each topic varies. For instance, the expertise needed to make a judgement on biological relevance of a specific tumour type is clearly different to that needed to determine the statistical uncertainty around the data used for modelling a benchmark dose. As such, each topic is dealt with separately to allow those with specialised knowledge to target key areas of guidance and provide a more in-depth discussion on each subject for those new to the concept of the Margin of Exposure approach.

Safety of GM Crops: Compositional Analysis

The compositional analysis of genetically modified (GM) crops has continued to be an important part of the overall evaluation in the safety assessment program for these materials. The variety and complexity of genetically engineered traits and modes of action that will be used in GM crops in the near future, as well as our expanded knowledge of compositional variability and factors that can affect composition, raise questions about compositional analysis and how it should be applied to evaluate the safety of traits. The International Life Sciences Institute (ILSI), a nonprofit foundation whose mission is to provide science that improves public health and well-being by fostering collaboration among experts from academia, government, and industry, convened a workshop in September 2012 to examine these and related questions, and a series of papers has been assembled to describe the outcomes of that meeting.

Monitoring immune modulation by nutrition in the general population: identifying and substantiating effects on human health

Optimal functioning of the immune system is crucial to human health, and nutrition is one of the major exogenous factors modulating different aspects of immune function. Currently, no single marker is available to predict the effect of a dietary intervention on different aspects of immune function. To provide further guidance on the assessment and interpretation of the modulation of immune functions due to nutrition in the general population, International Life Sciences Institute Europe commissioned a group of experts from academia, government and the food industry to prepare a guidance document. A draft of this paper was refined at a workshop involving additional experts. First, the expert group defined criteria to evaluate the usefulness of immune function markers. Over seventy-five markers were scored within the context of three distinct immune system functions: defence against pathogens; avoidance or mitigation of allergy; control of low-grade (metabolic) inflammation. The most useful markers were subsequently classified depending on whether they by themselves signify clinical relevance and/or involvement of immune function. Next, five theoretical scenarios were drafted describing potential changes in the values of markers compared with a relevant reference range. Finally, all elements were combined, providing a framework to aid the design and interpretation of studies assessing the effects of nutrition on immune function. This stepwise approach offers a clear rationale for selecting markers for future trials and provides a framework for the interpretation of outcomes. A similar stepwise approach may also be useful to rationalise the selection and interpretation of markers for other physiological processes critical to the maintenance of health and well-being.

Compositional Analysis of Genetically Modified (GM) Crops: Key Issues and Future Needs

Effective symposia need two strong legs to stand upon: informative presentations of recent research paired with lively discussion of these topics. Although it is easy for the organizers of a symposium to predict the usefulness of the former, as they select the speakers and their topic areas, guaranteeing productive discussion is a far more difficult task. For the Crop Composition Workshop sponsored by the International Life Sciences Institute's Committee on Food and Biotechnology (ILSI IFBIC), the organizers scheduled four roundtable discussions with preselected questions and with rapporteurs drawn from governmental organizations and public-sector research institutes (the authors). It was also the organizers' intent to let these discussions flow on the basis of the experiences of the participants and pressing issues within the overall debate on the role of crop compositional analysis within safety assessment of biotechnology as it exists now and in the future. The goal of this perspective is to summarize the issues raised, providing references when possible, and to describe the consensus statements reached through the course of these discussions.

Availability and Utility of Crop Composition Data

The safety assessment of genetically modified (GM) crops is mandatory in many countries. Although the most important factor to take into account in these safety assessments is the primary effects of artificially introduced transgene-derived traits, possible unintended effects attributed to the insertion of transgenes must be carefully examined in parallel. However, foods are complex mixtures of compounds characterized by wide variations in composition and nutritional values. Food components are significantly affected by various factors such as cultivars and the cultivation environment including storage conditions after harvest, and it can thus be very difficult to detect potential adverse effects caused by the introduction of a transgene. A comparative approach focusing on the identification of differences between GM foods and their conventional counterparts has been performed to reveal potential safety issues and is considered the most appropriate strategy for the safety assessment of GM foods. This concept is widely shared by authorities in many countries. For the efficient safety assessment of GM crops, an easily accessible and wide-ranging compilation of crop composition data is required for use by researchers and regulatory agencies. Thus, we developed an Internet-accessible food composition database comprising key nutrients, antinutrients, endogenous toxicants, and physiologically active substances of staple crops such as rice and soybeans. The International Life Sciences Institute has also been addressing the same matter and has provided the public a crop composition database of soybeans, maize, and cotton.