Position of the Academy of Nutrition and Dietetics: nutritional genomics

Personalized nutrition: the end of the one-diet-fits-all era

Personalized Nutrition emerged as a new trend for providing nutritional and food advice based on the individual's genetic composition, a field driven by the advancements in the multi-omic sciences throughout the last century. It intends not only to tailor the recommended daily allowances of nutrients and functional foods that a person may need but also to maintain the principles of sustainability and eco-friendliness. This principle implies the implementation of strategies within the healthcare system to advocate for the ending of the one-diet-fits-all paradigm by considering a personalized diet as an ally to prevent diet-related chronic diseases. In this Perspective, we highlight the potential benefits of such a paradigm within the region of Latin America, particularly Mexico, where the genetic admixture of the population, food biodiversity, and food culture provide unique opportunities to establish personalized nutrigenetic strategies. These strategies could play a crucial role in preventing chronic diseases and addressing the challenges confronted in the region.

Forgetting how we ate: personalised nutrition and the strategic uses of history

Personalised nutrition (PN) has emerged over the past twenty years as a promising area of research in the postgenomic era and has been popularized as the new big thing out of molecular biology. Advocates of PN claim that previous approaches to nutrition sought general and universal guidance that applied to all people. In contrast, they contend that PN operates with the principle that "one size does not fit all" when it comes to dietary guidance. While the molecular mechanisms studied within PN are new, the notion of a personal dietary regime guided by medical advice has a much longer history that can be traced back to Galen's "On Food and Diet" or Ibn Sina's (westernized as Avicenna) "Canon of Medicine". Yet this history is either wholly ignored or misleadingly appropriated by PN proponents. This (mis)use of history, we argue helps to sustain the hype of the novelty of the proposed field and potential commodification of molecular advice that undermines longer histories of food management in premodern and non-Western cultures. Moreover, it elides how the longer history of nutritional advice always happened in a heavily moralized, gendered, and racialized context deeply entwined with collective technologies of power, not just individual advice. This article aims at offering a wider appreciation of this longer history to nuance the hype and exceptionalism surrounding contemporary claims.

Obesity and Nutrigenetics Testing: New Insights

BACKGROUND

Obesity results from interactions between environmental factors, lifestyle, and genetics. In this scenario, nutritional genomics and nutrigenetic tests stand out, with the promise of helping patients avoid or treat obesity. This narrative review investigates whether nutrigenetic tests may help to prevent or treat obesity. Scientific studies in PubMed Science Direct were reviewed, focusing on using nutrigenetic tests in obesity. The work showed that few studies address the use of tools in obesity. However, most of the studies listed reported their beneficial effects in weight loss. Ethical conflicts were also discussed, as in most countries, there are no regulations to standardize these tools, and there needs to be more scientific knowledge for health professionals who interpret them. International Societies, such as the Academy of Nutrition and Dietetics and the Brazilian Association for the Study of Obesity and Metabolic Syndrome, do not recommend nutrigenetic tests to prevent or treat obesity, especially in isolation. Advancing nutrigenetics depends on strengthening three pillars: regulation between countries, scientific evidence with clinical validity, and professional training.

Integrating nutrition and genetic counseling: A case study approach to interprofessional learning

Interprofessional collaboration is an increasingly important skillset for practicing healthcare professionals including genetic counselors and registered dietitian nutritionists. A multi-part interactive case study activity was created to develop interprofessional skills for graduate students within genetic counseling and medical nutrition training programs at an academic medical center. Feedback from learners who participated in this activity highlights its effect on their post-graduation clinical practice. Additionally, since the implementation of this activity, collaboration between students and faculty members of each program has occurred in other scholarly pursuits, fostering longstanding interprofessional relationships. Similar approaches to interprofessional education could be considered with other healthcare professions or at other institutions as another tool to strengthen practice upon graduation.

The declining insulinogenic index correlates with inflammation and metabolic dysregulation in non-obese individuals assessed by blood gene expression

AIMS

Diabetes onset is difficult to predict. Since decreased insulinogenic index (IGI) is observed in prediabetes, and blood gene expression correlates with insulin secretion, candidate biomarkers can be identified.

METHODS

We collected blood from 96 participants (54 males, 42 females) in 2008 (age: 52.5 years) and 2016 for clinical and gene expression analyses. IGI was derived from values of insulin and glucose at fasting and at 30 min post-OGTT. Two subgroups were identified based on IGI variation: "Minor change in IGI" group with absolute value variation between -0.05 and +0.05, and "Decrease in IGI" group with a variation between -20 and -0.05.

RESULTS

Following the comparison of "Minor change in IGI" and "Decrease in IGI" groups at time 0 (2008), we identified 77 genes correlating with declining IGI, related to response to lipid, carbohydrate, and hormone metabolism, response to stress and DNA metabolic processes. Over the eight years, genes correlating to declining IGI were related to inflammation, metabolic and hormonal dysregulation. Individuals with minor change in IGI, instead, featured homeostatic and regenerative responses.

CONCLUSIONS

By blood gene expression analysis of non-obese individuals, we identified potential gene biomarkers correlating to declining IGI, associated to a pathophysiology of inflammation and metabolic dysregulation.

Specific Genotypes Associated with Differences in Fasting Insulin Levels and Body Mass Index in Healthy Young Males: Implications for Gene-Nutrient Interactions-an Exploratory Study

Background

Genetic variation may significantly impact an individual's susceptibility to diseases, particularly when combined with specific nutrients. Additionally, genetic variations can lead to interindividual differences in metabolic responses.

Objective

The present study explores the association between gene variants and observed interindividual differences in metabolic responses.

Methods

The study included 30 healthy males (aged 20-34) who underwent a fasting period and subsequently consumed a standardized meal. Blood samples were collected both before and after the meal to assess metabolic changes. BMI served as an indirect measure for assessing physiological responses associated with body composition. Appetite changes were assessed using an online Visual Analog 100-point Scale. Buccal swabs were collected to analyze genetic variants in single nucleotide polymorphisms (SNPs).

Results

The data underwent multiple regression analysis, revealing significant associations with 3 SNPs and their metabolic status: the insulin-receptor substrate 1 (IRS1) gene variant rs2943641, genotypes CT and CC, with elevated fasting insulin levels (R2 = 0.639, P = < 0.0001); the mitochondrial uncoupling protein 1 (UCP1) gene variant rs1800592, genotypes GG and GA, with increased BMI (R2 = 0.261, P = 0.007); and the peroxisome proliferator-activated receptor γ2 (PPARγ2) gene variant rs1801282, genotypes GG and GC, with increased BMI (R2 = 0.200, P = 0.024).

Conclusions

Therefore, our study established significant associations between these 3 SNPs and differences in fasting insulin levels and BMI within our cohort.

Characterizing Precision Nutrition Discourse on Twitter: Quantitative Content Analysis

BACKGROUND

It is possible that tailoring dietary approaches to an individual's genomic profile could provide optimal dietary inputs for biological functioning and support adherence to dietary management protocols. The science required for such nutrigenetic and nutrigenomic profiling is not yet considered ready for broad application by the scientific and medical communities; however, many personalized nutrition products are available in the marketplace, creating the potential for hype and misleading information on social media. Twitter provides a unique big data source that provides real-time information. Therefore, it has the potential to disseminate evidence-based health information, as well as misinformation.

OBJECTIVE

We sought to characterize the landscape of precision nutrition content on Twitter, with a specific focus on nutrigenetics and nutrigenomics. We focused on tweet authors, types of content, and presence of misinformation.

METHODS

Twitter Archiver was used to capture tweets from September 1, 2020, to December 1, 2020, using keywords related to nutrition and genetics. A random sample of tweets was coded using quantitative content analysis by 4 trained coders. Codebook-driven, quantified information about tweet authors, content details, information quality, and engagement metrics were compiled and analyzed.

RESULTS

The most common categories of tweets were precision nutrition products and nutrigenomic concepts. About a quarter (132/504, 26.2%) of tweet authors presented themselves as science experts, medicine experts, or both. Nutrigenetics concepts most frequently came from authors with science and medicine expertise, and tweets about the influence of genes on weight were more likely to come from authors with neither type of expertise. A total of 14.9% (75/504) of the tweets were noted to contain untrue information; these were most likely to occur in the nutrigenomics concepts topic category.

CONCLUSIONS

By evaluating social media discourse on precision nutrition on Twitter, we made several observations about the content available in the information environment through which individuals can learn about related concepts and products. Tweet content was consistent with the indicators of medical hype, and the inclusion of potentially misleading and untrue information was common. We identified a contingent of users with scientific and medical expertise who were active in discussing nutrigenomics concepts and products and who may be encouraged to share credible expert advice on precision nutrition and tackle false information as this technology develops.

Análisis bioético del uso de la biotecnología genómica en la nutrición traslacional

Los avances de la biotecnología y las fascinantes perspectivas de la genómica nutricional en el escenario de la práctica clínica conducen a la consideración de distintos aspectos que impactan en el beneficio integral del ser humano. En ese sentido, la integración de la nutrición personalizada en la atención clínica requiere de un análisis bioético centrado en la unidad de la persona que, con base en su perfil nutrigenético único, contribuya al cuidado de la salud por medio del tratamiento nutricional individualizado. El análisis bioético contempla los principios de totalidad terapéutica, libertad e integridad. Además, el uso de las pruebas nutrigenéticas destaca no solo la confidencialidad de datos, que se presupone, sino que lleva a considerar el derecho a la intimidad.

Dysregulated Lipid Synthesis by Oncogenic IDH1 Mutation Is a Targetable Synthetic Lethal Vulnerability

Isocitrate dehydrogenase 1 and 2 (IDH) are mutated in multiple cancers and drive production of (R)-2-hydroxyglutarate (2HG). We identified a lipid synthesis enzyme [acetyl CoA carboxylase 1 (ACC1)] as a synthetic lethal target in mutant IDH1 (mIDH1), but not mIDH2, cancers. Here, we analyzed the metabolome of primary acute myeloid leukemia (AML) blasts and identified an mIDH1-specific reduction in fatty acids. mIDH1 also induced a switch to b-oxidation indicating reprogramming of metabolism toward a reliance on fatty acids. Compared with mIDH2, mIDH1 AML displayed depletion of NADPH with defective reductive carboxylation that was not rescued by the mIDH1-specific inhibitor ivosidenib. In xenograft models, a lipid-free diet markedly slowed the growth of mIDH1 AML, but not healthy CD34+ hematopoietic stem/progenitor cells or mIDH2 AML. Genetic and pharmacologic targeting of ACC1 resulted in the growth inhibition of mIDH1 cancers not reversible by ivosidenib. Critically, the pharmacologic targeting of ACC1 improved the sensitivity of mIDH1 AML to venetoclax.

SIGNIFICANCE

Oncogenic mutations in both IDH1 and IDH2 produce 2-hydroxyglutarate and are generally considered equivalent in terms of pathogenesis and targeting. Using comprehensive metabolomic analysis, we demonstrate unexpected metabolic differences in fatty acid metabolism between mutant IDH1 and IDH2 in patient samples with targetable metabolic interventions. See related commentary by Robinson and Levine, p. 266. This article is highlighted in the In This Issue feature, p. 247.

Nutritional Genomics in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a common chronic condition associated with genetic and environmental factors in which fat abnormally accumulates in the liver. NAFLD is epidemiologically associated with obesity, type 2 diabetes, and dyslipidemia. Environmental factors, such as physical inactivity and an unbalanced diet, interact with genetic factors, such as epigenetic mechanisms and polymorphisms for the genesis and development of the condition. Different genetic polymorphisms seem to be involved in this context, including variants in PNPLA3, TM6SF2, PEMT, and CHDH genes, playing a role in the disease's susceptibility, development, and severity. From carbohydrate intake and weight loss to omega-3 supplementation and caloric restriction, different dietary and nutritional factors appear to be involved in controlling the onset and progression of NAFLD conditions influencing metabolism, gene, and protein expression. The polygenic risk score represents a sum of trait-associated alleles carried by an individual and seems to be associated with NAFLD outcomes depending on the dietary context. Understanding the exact extent to which lifestyle interventions and genetic predispositions can play a role in the prevention and management of NAFLD can be crucial for the establishment of a personalized and integrative approach to patients.

Opportunities to integrate nutrigenomics into clinical practice and patient counseling

BACKGROUND

Little progress has been made in translating nutrigenomics knowledge into clinical counseling in the past decade. Currently, clinicians are overwhelmed by nutrigenomics information without the proper scientific guidelines on patient counseling.

METHODS

In this study, we conducted a scoping review of the primary literature to assess the current evidence of nutrigenomics counseling. A literature search using PRISMA guidelines identified the current challenges and opportunities facing nutrigenomics counseling in clinical practice.

RESULTS

We identified four main themes: inadequate training, lack of awareness, underdeveloped nutrigenomics counseling skills, and unreliable evidence-based practice information. Many clinicians did not have the necessary knowledge to perform nutrigenomic counseling and were unaware of the available scientific information source. Moreover, there are no guidelines in the scientific community to counsel patients on nutrigenomics testing.

CONCLUSION

Opportunities exist for government and non-government entities to create an evidence-based information platform using clinical guidelines to integrate nutrigenomics knowledge from bench to bedside successfully.

Olive Oil in the Mediterranean Diet and Its Biochemical and Molecular Effects on Cardiovascular Health through an Analysis of Genetics and Epigenetics

Human nutrition is a relatively new science based on biochemistry and the effects of food constituents. Ancient medicine considered many foods as remedies for physical performance or the treatment of diseases and, since ancient times, especially Greek, Asian and pre-Christian cultures similarly thought that they had beneficial effects on health, while others believed some foods were capable of causing illness. Hippocrates described the food as a form of medicine and stated that a balanced diet could help individuals stay healthy. Understanding molecular nutrition, the interaction between nutrients and DNA, and obtaining specific biomarkers could help formulate a diet in which food is not only a food but also a drug. Therefore, this study aims to analyze the role of the Mediterranean diet and olive oil on cardiovascular risk and to identify their influence from the genetic and epigenetic point of view to understand their possible protective effects.

Nutrigenomics: Perceptions of South African Dietitians and General Practitioners

INTRODUCTION

Although investigations into the emerging field of nutrigenomics are relatively limited and more research in this field is required, experts agree that there is potential for it to be incorporated into health care practice. If health care professionals can promote healthy dietary behavior based on nutrigenomic testing, it can assist in addressing the health consequences of poor diet and lightning the strain on the South African health care system.

METHODS

Registered dietitians (RDs) and general practitioners (GPs) registered with the Health Professions Council of South Africa (HPCSA) who obtained their qualification in South Africa (SA) were eligible to participate in this cross-sectional study. Participants were identified using convenience and snowball sampling. A self-administered electronic survey using EvaSys Software® was completed by those that agreed to participate.

RESULTS

Nearly all RDs (97.3%), but less than a third of GPs (30.4%), had heard of the term nutrigenomics. Approximately three-quarters of RDs (74.7%) and GPs (73.9%) had or would personally consider undergoing genetic testing. More than 40% (43.5%) of RDs ranked direct-to-consumer genetic testing companies as the most equipped, while 31.8% of GPs ranked RDs as the most equipped to provide patients with nutrigenomic services. Both RDs and GPs ranked similar reasons as "strongly agree" for why consumers were motivated to make use of nutrigenomic services, which included "motivated by a desire to prevent or manage disease" (56.7%), "prevent a disease based on family history" (65.9%), "control health outcomes based on family history" (54.9%), and "improve overall health-related quality of life" (48.6%). Cost concerns were reported as the greatest barrier to implementing nutrigenomic services (75.7%). Other barriers included confidentiality issues (47.8%) and moral concerns (37.3%). Greater individualization of diet prescription (66.5%), stronger foundations for nutrition recommendations (62.4%), and dietary prescriptions that would manage or prevent certain diseases more effectively (59.0%) were all perceived as benefits of including nutrigenomics in practice.

CONCLUSION

This study identified perceived consumer motivators and barriers that might affect the willingness to seek nutrigenomic services in SA. In addition, the need for more nutrigenomic training opportunities, including the planning of personalized diets based on genetic testing results and interpretation of results, was confirmed. However, both RDs and GPs felt that the emerging field of nutrigenomics needs further development before it can be applied effectively in routine private and public health care in SA.

Changes in Novel Anthropometric Indices of Abdominal Obesity during Weight Loss with Selected Obesity-Associated Single-Nucleotide Polymorphisms: A Small One-Year Pilot Study

Whether BMI and the competing waist circumference (WC)-based anthropometric indices are associated with obesity-related single-nucleotide polymorphisms (SNPs) is as yet unknown. The current study aimed to evaluate the anthropometric indices (fat mass index, body shape index, visceral adiposity index, relative fat mass, body roundness index, and conicity index) during a weight loss intervention in 36 obese individuals. Blood biochemical parameters (total cholesterol, low-density lipoprotein, high-density lipoprotein, and triglycerides) and three SNPs (FTO rs9939609, TFAP2B rs987237, and PLIN1 rs894160) were assessed in 22 women and 14 men (35.58 ± 9.85 years, BMI 35.04 ± 3.80 kg/m2) who completed a 12-month balanced energy-restricted diet weight loss program. Body composition was assessed via bioelectrical impedance (SECA mBCA515). At the end of the weight loss intervention, all anthropometric indices were significantly reduced (p < 0.05). For the SNP FTO rs9939609, the higher risk allele (A) was characteristic of 88.9% of the study group, in which 10 participants (27.8%) were homozygous. We found a similar distribution of alleles in TFAP2B and PLIN1. Heterozygous genotypes in FTO rs9939609 and TFAP2B rs987237 were predisposed to significant reductions in WC-based novel anthropometric indices during weight loss. The influence of PLIN1 rs894160 polymorphisms on the changes in the analyzed indices during weight loss has not been documented in the present study.

FTO and ADRB2 Genetic Polymorphisms Are Risk Factors for Earlier Excessive Gestational Weight Gain in Pregnant Women with Pregestational Diabetes Mellitus: Results of a Randomized Nutrigenetic Trial

Excessive gestational weight gain (GWG) is associated with increased risk of maternal and neonatal complications. We investigated obesity-related polymorphisms in the FTO gene (rs9939609, rs17817449) and ADRB2 (rs1042713, rs1042714) as candidate risk factors concerning excessive GWG in pregnant women with pregestational diabetes. This nutrigenetic trial, conducted in Brazil, randomly assigned 70 pregnant women to one of the groups: traditional diet (n = 41) or DASH diet (n = 29). Excessive GWG was the total weight gain above the upper limit of the recommendation, according to the Institute of Medicine guidelines. Genotyping was performed using real-time PCR. Time-to-event analysis was performed to investigate risk factors for progression to excessive GWG. Regardless the type of diet, AT carriers of rs9939609 (FTO) and AA carriers of rs1042713 (ADRB2) had higher risk of earlier exceeding GWG compared to TT (aHR 2.44; CI 95% 1.03-5.78; p = 0.04) and GG (aHR 3.91; CI 95% 1.12-13.70; p = 0.03) genotypes, respectively, as the AG carriers for FTO haplotype rs9939609:rs17817449 compared to TT carriers (aHR 1.79; CI 95% 1.04-3.06; p = 0.02).

"Right diet for the right person": a focus group study of nutritionist-dietitians' perspectives on nutritional genomics and gene-based nutrition advice

Advances in nutritional genomics are intended to revolutionize nutrition practice. A basic understanding of nutritional genomics among nutritionist-dietitians is critical for such advancements to occur. As a precedent to the development and integration of gene-based nutrition advice, this study aimed to assess hospital-based nutritionist-dietitians' perceptions of nutritional genomics. A total of ten focus group discussions (FGDs) with sixty-one registered nutritionist-dietitians (RNDs) from hospitals in the National Capital Region (NCR), Philippines, were conducted from October to November 2019. Data were collected using a pretested semistructured discussion guide, and thematic analysis was subsequently performed. Diverging perceptions about nutritional genomics were noted among the FGD participants. Five themes emerged relating to the enablers and barriers of gene-based nutrition advice: training and capacity building, the extent of information to be disclosed, cost, ethical considerations, and government support. Themes related to the desired features of the gene-based nutrition advice included being consent-driven, cost-effective, technology-oriented, and guided by standards. The results of this study suggest that training and continued learning will equip RNDs to provide nutrition advice based on genetic information. However, other factors, such as cost and ethical considerations, are critical dimensions that need to be acknowledged and addressed before integrating gene-based advice into nutrition practice.

Nutrition Concepts for the Treatment of Obesity in Adults

Obesity caused by a positive energy balance is a serious health burden. Studies have shown that obesity is the major risk factor for many diseases like type 2 diabetes mellitus, coronary heart diseases, or various types of cancer. Therefore, the prevention and treatment of increased body weight are key. Different evidence-based treatment approaches considering weight history, body mass index (BMI) category, and co-morbidities are available: lifestyle intervention, formula diet, drugs, and bariatric surgery. For all treatment approaches, behaviour change techniques, reduction in energy intake, and increasing energy expenditure are required. Self-monitoring of diet and physical activity provides an effective behaviour change technique for weight management. Digital tools increase engagement rates for self-monitoring and have the potential to improve weight management. The objective of this narrative review is to summarize current available treatment approaches for obesity, to provide a selective overview of nutrition trends, and to give a scientific viewpoint for various nutrition concepts for weight loss.

The Role of miR-155 in Nutrition: Modulating Cancer-Associated Inflammation

Nutrition plays an important role in overall human health. Although there is no direct evidence supporting the direct involvement of nutrition in curing disease, for some diseases, good nutrition contributes to disease prevention and our overall well-being, including energy level, optimum internal function, and strength of the immune system. Lately, other major, but more silent players are reported to participate in the body’s response to ingested nutrients, as they are involved in different physiological and pathological processes. Furthermore, the genetic profile of an individual is highly critical in regulating these processes and their interactions. In particular, miR-155, a non-coding microRNA, is reported to be highly correlated with such nutritional processes. In fact, miR-155 is involved in the orchestration of various biological processes such as cellular signaling, immune regulation, metabolism, nutritional responses, inflammation, and carcinogenesis. Thus, this review aims to highlight those critical aspects of the influence of dietary components on gene expression, primarily on miR-155 and its role in modulating cancer-associated processes.

Healthcare Professional Clinical Actions following Nutrigenomics Testing in Practice

<b><i>Background:</i></b> Clinical demand for nutrigenomics testing (NGT) is increasing, underscoring the importance of assessing healthcare professional (HCP) competence and clinical actions with NGT in practice. While previous studies have explored HCP perceptions of NGT, no study has examined real HCP experiences with NGT in practice. <b><i>Objective:</i></b> The objective of this study was to evaluate the clinical experience of providing NGT among early adopter HCPs who have used NGT in their practice. We hypothesized that HCP clinical actions after NGT would differ according to HCP personal experience undergoing genetic testing (GT) as well as years in practice. <b><i>Design:</i></b> An online survey questionnaire was administered to HCPs (<i>n</i> = 70) who have provided NGT in practice. χ² tests, tests for trend, and logistic regression were used to compare HCP characteristics with post-NGT outcomes. <b><i>Results:</i></b> HCPs with fewest years in practice (&#x3c;5 years) comprised the lowest proportion of respondents (16%). Most HCPs reported good understanding of NGT results and 92% made genetic-based dietary recommendations to patients following NGT. HCP personal use of GT increased significantly with increasing years in practice (&#x3c;5 years: 36%, 5–10 years: 53%, 11–20 years: 70%, and &#x3e;20 years: 85%, <i>p</i> trend = 0.003). Requesting patient bloodwork because of NGT results increased significantly with HCP years in practice when HCPs with &#x3c;5 years in practice were not considered (5–10 years: 19%, 11–20 years: 28%, and &#x3e;20 years: 60%, <i>p</i> trend = 0.010). A near significant difference was observed where a greater proportion of HCPs who had personally undergone GT reported requesting patient bloodwork (personal use: 46% vs. no personal use: 23%, <i>p</i>-χ² = 0.066). <b><i>Conclusion:</i></b> Early HCP adopters of NGT utilize the test results to provide genetic-based dietary recommendations to patients. Clinical action after NGT currently appears to be driven by HCP years in practice, but HCP personal use of GT may also be a factor.

Knowledge, opinions and expectations of adults concerning personalised genotype-based dietary recommendations: a German survey

Objective:

To assess the knowledge, opinions and expectations of persons with and without obesity concerning personalised genotype-based nutrition.

Design:

Questions about nutrition, weight management and personalised genotype-based dietary recommendations were asked via standardised telephone-based interviews. Sociodemographic and anthropometric data were collected. The data were statistically weighted by age, gender, education, domicile and BMI.

Setting:

Germany.

Participants:

Representative sample of the German population (n 1003) randomly sampled via a scientific Random Digit dial method plus 354 adults with a BMI ≥ 30·0 kg/m² to enlarge the sample.

Results:

Data of 1357 participants were analysed (51·1 % female, age: 50·5 ± 18·5 years, 15·9 % adults with a BMI ≥ 30·0 kg/m²). About 42 % or 19 % of the survey participants stated to know the terms personalised dietary recommendation or genotype-based dietary recommendation, respectively. Of those, 15·8 % indicated to have an experience with a personalised or genotype-based dietary recommendation. Almost 70 % of the survey participants believed that a genotype-based dietary recommendation is a reasonable measure for weight management. About 55 % of the survey participants pointed out that a genotype-based dietary recommendation is an effective concept in general. One-third of the survey participants (34·6 %) indicated to conceive the usage of a genotype-based dietary recommendation.

Conclusion:

Most of the survey participants did not know the term personalised or genotype-based dietary recommendation. One-third of the study participants are interested to use a genotype-based dietary recommendation. Therefore, more education of the public is necessary to properly help people making informed and serious decisions and assessing commercially available direct-to-consumer genetic tests.

Genomics in Personalized Nutrition: Can You "Eat for Your Genes"?

Genome-wide single nucleotide polymorphism (SNP) data are now quickly and inexpensively acquired, raising the prospect of creating personalized dietary recommendations based on an individual's genetic variability at multiple SNPs. However, relatively little is known about most specific gene-diet interactions, and many molecular and clinical phenotypes of interest (e.g., body mass index [BMI]) involve multiple genes. In this review, we discuss direct to consumer genetic testing (DTC-GT) and the current potential for precision nutrition based on an individual's genetic data. We review important issues such as dietary exposure and genetic architecture addressing the concepts of penetrance, pleiotropy, epistasis, polygenicity, and epigenetics. More specifically, we discuss how they complicate using genotypic data to predict phenotypes as well as response to dietary interventions. Then, several examples (including caffeine sensitivity, alcohol dependence, non-alcoholic fatty liver disease, obesity/appetite, cardiovascular, Alzheimer's disease, folate metabolism, long-chain fatty acid biosynthesis, and vitamin D metabolism) are provided illustrating how genotypic information could be used to inform nutritional recommendations. We conclude by examining ethical considerations and practical applications for using genetic information to inform dietary choices and the future role genetics may play in adopting changes beyond population-wide healthy eating guidelines.

Panorama da nutrigenômica no Brasil sob a perspectiva da Bioética

A nutrigenômica tem configurado, no meio científico e popular, como alternativa para prevenir doenças, cuja predisposição determinada geneticamente pode ser evitada ou estimulada, de- pendendo do ambiente no qual o indivíduo se insere. Este estudo questionou o potencial da nutrigenômica em mitigar ou gerar vulnerabilidades. Objetivou-se traçar o panorama da nutrigenômica no Brasil sob a perspectiva da Bioética. O estudo consistiu em um mapeamento quantitativo do panora- ma da nutrigenômica no cenário científico e popular do Brasil, e em uma análise bibliográfica exploratória com o intuito de identificar os agentes e pacientes morais, bem como as vulnerabilidades com vistas a promover uma reflexão à luz da Bioética. O cenário da nutrigenômica no Brasil, elaborado a partir de 18 textos científicos e de 600 conteúdos populares, indicou a prematuridade da área no contexto científico em confronto com uma ampla incorporação pelo meio popular. A incorporação da Bioética na questão foi analisada em 44 artigos científicos, a partir dos quais foram identificados como aspectos condicionantes de decisões do agente moral os contextos filosófico, biológico, cultural, legal e sanitário nos quais se insere. Foram elencadas as vulnerabilidades e mudanças de paradigmas necessárias para sua implementação no Brasil, a fim de diminuir o potencial de geração de vulnerabilidades. A Bioética pode e deve ter uma atuação mais ampla e efetiva nas questões da nutrigenômica ao normatizar, balizar e orientar o desenvolvimento dessa área promissora. Assim, deve visar às mudanças de paradigmas da ciência, dos profissionais, do mercado, do paciente e do consumidor para serem suprimidos os aspectos potenciais de geração das vulnerabilidades identificadas e contribuir para a qualidade de vida de todos os seres vivos desta e de futuras gerações.

Integrative Nutrition CARE in the Community-Starting with Pharmacists

Dietary supplementation is increasingly sought after by consumers looking to meet the demands of a modern lifestyle. Effective supplementation requires knowledge of the purpose and proper use of nutritional supplements. Unverified or inadequate guidance on supplementation can propagate misconceptions and increase undue fears of side effects. Community pharmacists are best placed to guide consumers on nutritional supplement use. In this review, a panel comprised of community pharmacists, pharmacy academia, and dietitians (n = 6) convened to provide an experience- and evidence-based guidance on rational drug use, patient education, and integrated and personalized nutrition care in both community and hospital pharmacy settings. A novel framework to guide community pharmacist-led consultations on supplementation is proposed. The four-step CARE (Categorize, Assess, Recommend, Empower) guide was developed to facilitate and optimize outcomes of pharmacist-led nutritional supplement consultation. Telehealth advancements in the form of digital health applications and personalized nutrigenomic DNA testing support Integrative Nutrition Care, and will further promote appropriate supplementation use to improve overall well-being in the community. Practical implementation of the CARE guide is necessary to ascertain its applicability for optimizing outcomes of pharmacist-led consultation and the recommendation of nutritional supplements.

Consensus Report of the Academy of Nutrition and Dietetics: Incorporating Genetic Testing into Nutrition Care

Personalization of nutrition advice is a process already familiar to registered dietitian nutritionists, but it is not yet clear whether incorporating genetic results as an added layer of precision improves nutrition-related outcomes. Therefore, an independent workgroup of experts, supported by the Academy's Evidence Analysis Center staff, conducted a systematic review to examine the level of evidence measuring the effect of incorporating genetic testing results into nutrition counseling and care, compared to an alternative intervention or control group, on nutrition-related outcomes. This systematic review revealed that only weak quality evidence is available in the scientific literature and observed that this field is still maturing. Therefore, at present, there is insufficient scientific evidence to determine whether there are effects of incorporating genetic testing into nutrition practice. The workgroup prepared this Consensus Report based on this systematic review to provide considerations for the practical application of incorporating genetic testing into the nutrition care process.

Effect of Incorporating Genetic Testing Results into Nutrition Counseling and Care on Dietary Intake: An Evidence Analysis Center Systematic Review-Part I

Consumer interest in personalized nutrition based on nutrigenetic testing is growing. Recently, multiple, randomized controlled trials have sought to understand whether incorporating genetic information into dietary counseling alters dietary outcomes. The objective of this systematic review was to examine how incorporating genetic information into nutrition counseling and care, compared to an alternative intervention or control group, impacts dietary outcomes. This is the first of a 2-part systematic review series. Part II reports anthropometric, biochemical, and disease-specific outcomes. Peer-reviewed randomized controlled trials were identified through a systematic literature search of multiple databases, screened for eligibility, and critically reviewed and synthesized. Conclusion statements were graded to determine quality of evidence for each dietary outcome reported. Reported outcomes include intake of total energy and macronutrients, micronutrients, foods, food groups, food components (added sugar, caffeine, and alcohol), and composite diet scores. Ten articles representing 8 unique randomized controlled trials met inclusion criteria. Of 15 conclusion statements (evidence grades: Weak to Moderate), 13 concluded there was no significant effect of incorporating genetic information into nutrition counseling/care on dietary outcomes. Limited data suggested that carriers of higher-risk gene variants were more likely than carriers of low-risk gene variants to significantly reduce intake of sodium and alcohol in response to nutrition counseling that incorporated genetic results. Included studies differed in quality, selected genetic variants, timing and intensity of intervention, sample size, dietary assessment tools, and population characteristics. Therefore, strong conclusions could not be drawn. Collaboration between the Academy of Nutrition and Dietetics and professional nutrigenetic societies would likely prove valuable in prioritizing which genetic variants and targeted nutrition messages have the most potential to alter dietary outcomes in a given patient subpopulation and, thus, should be the targets of future research.

Genetic and Genomic Advances in Developmental Models: Applications for Nutrition Research

There is increasing appreciation that dietary components influence and interact with genes important to metabolism. How such influences impact developmental regulation and programming or risks of chronic diseases remains unclear. Nutrition is recognized to affect development and chronic diseases, but our understanding about how genes essential to nutrient metabolism regulate development and impact risks of these diseases remains unclear. Historically, mammalian models, especially rodents such as rats and mice, have been the primary models used for nutrition and developmental nutrition science, although their complexity and relatively slow rate of development often compromise rapid progress in resolving fundamental, genetic-related questions. Accordingly, the objective of this review is to highlight the opportunities for developmental models in the context of uncovering the function of gene products that are relevant to human nutrition and provide the scientific bases for these opportunities. We present recent studies in zebrafish related to obesity as applications of developmental models in nutritional science. Although the control of external factors and dependent variables, such as nutrition, can be a challenge, suggestions for standardizations related to diet are made to improve consistency in findings between laboratories. The review also highlights the need for standardized diets across different developmental models, which could improve consistency in findings across laboratories. Alternative and developmental animal models have advantages and largely untapped potential for the advancement of nutrigenomics and nutritionally relevant research areas.

The relevance of nutrition to pediatric oncology: A cancer control perspective

It is indisputable that adequate and appropriate nutrition is fundamental to the health, growth, and development of infants, children, and adolescents, including those with cancer. Nutrition has a role in most of the accepted components of the cancer control spectrum, from prevention through to palliation. The science of nutrigenomics, nutrigenetics, and bioactive foods (phytochemicals), and how nutrition affects cancer biology and cancer treatment, is growing. Nutritional epigenetics is giving us an understanding that there are possible primary prevention strategies for pediatric cancers, especially during conception and pregnancy, which need to be studied. Primary prevention of cancer in adults, such as colorectal cancer, should commence early in childhood, given the long gestation of nutritionally related cancers. Obesity avoidance is definitely a target for both pediatric and adult cancer prevention, commencing in childhood. There is now compelling evidence that the nutritional status of children with cancer, both overweight and underweight, does affect cancer outcomes. This is a potentially modifiable prognostic factor. Consistent longitudinal nutritional assessment of patients from diagnosis through treatment and long-term follow-up is required so that interventions can be implemented and evaluated. While improving, there remains a dearth of basic and clinical nutritional research in pediatric oncology. The perspective of evaluating nutrition as a cancer control factor is discussed in this article.

Immunometabolism: new insights and lessons from antigen-directed cellular immune responses

Modulation of immune responses by nutrients is an important area of study in cellular biology and clinical sciences in the context of cancer therapies and anti-pathogen-directed immune responses in health and disease. We review metabolic pathways that influence immune cell function and cellular persistence in chronic infections. We also highlight the role of nutrients in altering the tissue microenvironment with lessons from the tumor microenvironment that shapes the quality and quantity of cellular immune responses. Multiple layers of biological networks, including the nature of nutritional supplements, the genetic background, previous exposures, and gut microbiota status have impact on cellular performance and immune competence against molecularly defined targets. We discuss how immune metabolism determines the differentiation pathway of antigen-specific immune cells and how these insights can be explored to devise better strategies to strengthen anti-pathogen-directed immune responses, while curbing unwanted, non-productive inflammation.

Nutritional genomics, inflammation and obesity

The Human Genome Project has significantly broadened our understanding of the molecular aspects regulating the homeostasis and the pathophysiology of different clinical conditions. Consequently, the field of nutrition has been strongly influenced by such improvements in knowledge - especially for determining how nutrients act at the molecular level in different conditions, such as obesity, type 2 diabetes, cardiovascular disease, and cancer. In this manner, characterizing how the genome influences the diet and vice-versa provides insights about the molecular mechanisms involved in chronic inflammation-related diseases. Therefore, the present review aims to discuss the potential application of Nutritional Genomics to modulate obesity-related inflammatory responses. Arch Endocrinol Metab. 2020;64(3):205-22.

Using document analysis to identify core concepts for dietetics: The first step in promoting conceptual learning

Concept-based approaches to curriculum design have been proposed in nursing and health sciences education to address the issue of content overload in curricula but have not been described in dietetics. This study aimed to identify core concepts for the dietetics discipline in Australia and investigate the commonality and differences in these concepts across different dietetic organizations across the world. This study used document analysis of a purposive sample of international dietetics competency or proficiency standards identified from English-speaking dietetic organizations worldwide. Content analysis was applied to the performance criteria or equivalent from 10 documents (nine organizations) to identify the most common elements. A total of 1,007 statements were analyzed. Fifty-six concepts were developed. The four most frequent concepts coded across all statements were "critical thinking," "communication," "nutrition and dietetic service," and "quality assurance and improvement." There were 55 concepts common to all standards. The concept of "food security" was not present in one of the standards from the United States. The concepts that emerged from this study were common across different English-speaking dietetic organizations across the world. Small differences on the emphasis of concepts, between different competency standards may reflect the health needs; health, political, economic, and social systems; and the cultural context of a country. Identifying core concepts in dietetics is the first step to help to inform curriculum design, which may address overcrowded curricular and promote conceptual learning.

Knowledge and Attitudes Towards Nutrigenetics: Findings from the 2018 Unified Forces Preventive Nutrition Conference (UFPN)

Background: Nutrigenetics indicates that individual genetic variability results in altered health outcomes necessitating personalized nutrition adaptation. Registered dietitians are recognized as the clinical nutrition experts, but their knowledge and attitudes regarding nutrigenetics has not been delineated. Methods: This cross sectional online survey was conducted in a convenience sample of 169 national nutrition conference attendees. The survey queried demographics, knowledge, and attitudes towards nutrigenetics and information on training in nutrigenetics. Results: The majority of participants were registered dietitians and female, 45% of whom held advanced degrees. Personalized nutrition was perceived by 93.5% of participants as highly important or important; however, 94% of respondents indicated they are not sufficiently knowledgeable in personalized nutrition and only 9.5% had received training in nutrigenetics. The mean nutrigenetics knowledge score was 6.89 ± 1.67 (out of a possible 12). A multivariate regression model of knowledge score identified education as the only independent predictor of this outcome. Conclusion: Personalized nutrition is a rapidly developing field that incorporates genetic data into clinical practice. Dietitians recognize the importance of advanced studies to acquire knowledge in nutrigenetics. Only by acquiring the necessary knowledge can dietitians accurately translate this nutrigenetics into clinical practice.

Using gold nanoparticles to detect single-nucleotide polymorphisms: toward liquid biopsy

The possibility of detecting genetic mutations rapidly in physiological media through liquid biopsy has attracted the attention within the materials science community. The physical properties of nanoparticles combined with robust transduction methods ensure an improved sensitivity and specificity of a given assay and its implementation into point-of-care devices for common use. Covering the last twenty years, this review gives an overview of the state-of-the-art of the research on the use of gold nanoparticles in the development of colorimetric biosensors for the detection of single-nucleotide polymorphism as cancer biomarker. We discuss the main mechanisms of the assays that either are assisted by DNA-based molecular machines or by enzymatic reactions, summarize their performance and provide an outlook towards future developments.

Dietary Restrictions and Nutrition in the Prevention and Treatment of Cardiovascular Disease

Cardiovascular disease (CVD) is the leading cause of death in many developed countries and remains one of the major diseases strongly affected by the diet. Nutrition can affect CVD directly by contributing to the accumulation of vascular plaques and also indirectly by regulating the rate of aging. This review summarizes research on nutrition and CVD incidence based on a multipillar system that includes basic research focused on aging, epidemiological studies, clinical studies, and studies of centenarians. The relevant research linking nutrition and CVD with focus on macronutrients and aging will be highlighted. We will review some of the most relevant studies on nutrition and CVD treatment, also focusing on interventions known to delay aging. We will discuss both everyday dietary compositions, as well as intermittent and periodic fasting interventions with the potential to prevent and treat CVD.

Position of the Academy of Nutrition and Dietetics: Micronutrient Supplementation

It is the position of the Academy of Nutrition and Dietetics that micronutrient supplements are warranted when requirements are not being met through the diet alone. Those with increased requirements secondary to growth, chronic disease, medication use, malabsorption, pregnancy and lactation, and aging may be at particular risk for inadequate dietary intakes. However, the routine and indiscriminate use of micronutrient supplements for the prevention of chronic disease is not recommended, given the lack of available scientific evidence. A few specific age and disease states that may benefit from micronutrient supplementation are discussed. The most common dietary supplements used by both children and adults in the United States contain micronutrients. Consumers may not be well informed about the safety and use of these products, and some may have difficulty interpreting product labels. Thus, the expertise of registered dietitian nutritionists and nutrition and dietetic technicians, registered, is needed to guide the safe and appropriate selection and use of micronutrient supplements. To accomplish this, registered dietitian nutritionists and nutrition and dietetic technicians, registered, must keep up to date on efficacy, safety, and the regulatory issues influencing the use of these products. This position paper aims to increase awareness of current issues relevant to micronutrient supplementation and of the resources available to assist registered dietitian nutritionists and nutrition and dietetic technicians, registered, in evaluating their potential benefits and adverse outcomes.

Dynamic Macronutrient Meal-Equivalent Menu Method: Towards Individual Nutrition Intervention Programs

Nutrition interventions should reflect the state of the art in science and dietetics to meet each patient's requirements. Incorporating new knowledge into individualized food-based nutrition interventions is a major challenge, and health care professionals constantly search for novel approaches through specific and standardized methods. The dynamic macronutrient meal-equivalent menu method involves individuals making informed food choices that match their requirements, schedule, and food availability and affinity, helping them maintain a sense of control and motivation to adhere to a nutrition intervention program. This protocol includes the steps required to prepare a nutrition plan containing equivalent meal options consistent with the patient's needs and preferences. Standard food servings are planned according to population specific dietary guidelines and individual characteristics. Servings are distributed at required mealtimes, and are all equivalent in energy and macronutrient content, providing every patient with interchangeable choices within each mealtime. This empowers individuals to select foods in a guided format whilst adhering to a dietary plan. Acceptable variations for calculated energy and macronutrient content are as follows: protein ±1 g/day, fat ±1 g/day, carbohydrate ±2 g/day, and energy ±15 kcal/day. Following this method, health care professionals can develop individualized nutrition intervention programs that may improve patients' adherence, nutritional status, and health.

Effects of Dietary Nutrients on Epigenetic Changes in Cancer

Gene-nutrient interactions are important contributors to health management and disease prevention. Nutrition can alter gene expression, as well as the susceptibility to disease, including cancer, through epigenetic changes. Nutrients can influence the epigenetic status through several mechanisms, such as DNA methylation, histone modifications, and miRNA-dependent gene silencing. These alterations were associated with either increased or decreased risk for cancer development. There is convincing evidence indicating that several foods have protective roles in cancer prevention, by inhibiting tumor progression directly or through modifying tumor's microenvironment that leads to hostile conditions favorable to tumor initiation or growth. While nutritional intakes from foods cannot be adequately controlled for dosage, the role of nutrients in the epigenetics of cancer has led to more research aimed at developing nutriceuticals and drugs as cancer therapies. Clinical studies are needed to evaluate the optimum doses of dietary compounds, the safety profile of dosages, to establish the most efficient way of administration, and bioavailability, in order to maximize the beneficial effects already discovered, and to ensure replicability. Thus, nutrition represents a promising tool to be used not only in cancer prevention, but hopefully also in cancer treatment.

"Omics" Education in Dietetic Curricula: A Comparison between Two Institutions in the USA and Mexico

BACKGROUND/AIMS

The completion of sequencing of the human genome and a better understanding of epigenomic regulation of gene expression have opened the possibility of personalized nutrition in the near future. This has also created an immediate need for trained personnel qualified to administer personalized nutrition education. Of all the allied healthcare personnel, dietitians are the most likely to undertake this role. However, dietitians and dietetic students are still deficient in their knowledge of nutrigenomics and other "omics" technologies. Therefore, with the eventual goal of dietetic curriculum reorganization, the International Society of Nutrigenetics/Nutrigenomics (ISNN) has set out to evaluate nutrigenomic knowledge among dietetic students from different countries. In this study, we compared nutrition and dietetic students from Texas Woman's University (TWU) and the Universidad Autónoma de Nuevo León (UANL) for their perceived need for, interest in, and knowledge of different topics within nutritional genomics.

METHODS

Students from both universities were sent an e-mail link to the survey which was located at psychdata.com. One hundred twenty-seven students completed the survey. The survey assessed the students' knowledge of, perceived need for, and interest in different omics technologies, as well as their basic knowledge of basic nutrition and genetic topics. Differences were assessed using the χ2 test for homogeneity and Fisher's exact test.

RESULTS

Students from TWU and UANL exhibited differences in their knowledge, desire to learn more, and perceived need for omics science in some but not all categories.

CONCLUSIONS

Undergraduate nutrition students from both the USA and Mexico lack a high level of knowledge in different omics topics but recognize the role that omics will play in their future as dietitians. There were differences between the 2 universities in terms of the desire to learn more about different omics technologies and to take more classes covering different topics with nutritional genomic components. In order to make personalized nutrition a reality, future dietitians will need to become fluent in different omics technologies.

Paving the Way to Precision Nutrition Through Metabolomics

Nutrition is an interdisciplinary science that studies the interactions of nutrients with the body in relation to maintenance of health and well-being. Nutrition is highly complex due to the underlying various internal and external factors that could model it. Thus, hacking this complexity requires more holistic and network-based strategies that could unveil these dynamic system interactions at both time and space scales. The ongoing omics era with its high-throughput molecular data generation is paving the way to embrace this complexity and is deeply reshaping the whole field of nutrition. Understanding the future paths of nutrition science is of importance from both translational and clinical perspectives. Basic nutrients which might include metabolites are important in nutrition science. Moreover, metabolites are key biological communication channels and represent an appealing functional readout at the interface of different major influential factors that define health and disease. Metabolomics is the technology that enables holistic and systematic analyses of metabolites in a biological system. Hence, given its intrinsic functionality, its tight connection to metabolism and its high clinical actionability potential, metabolomics is a very appealing technology for nutrition science. The ultimate goal is to deliver a tailored and clinically relevant nutritional recommendations and interventions to achieve precision nutrition. This work intends to present an update on the applications of metabolomics to personalize nutrition in translational and clinical settings. It also discusses the current conceptual shifts that are remodeling clinical nutrition practices in this Precision Medicine era. Finally, perspectives of clinical nutrition in the ever-growing, data-driven healthcare landscape are presented.

A Scientific Perspective of Personalised Gene-Based Dietary Recommendations for Weight Management

Various studies showed that a "one size fits all" dietary recommendation for weight management is questionable. For this reason, the focus increasingly falls on personalised nutrition. Although there is no precise and uniform definition of personalised nutrition, the inclusion of genetic variants for personalised dietary recommendations is more and more favoured, whereas scientific evidence for gene-based dietary recommendations is rather limited. The purpose of this article is to provide a science-based viewpoint on gene-based personalised nutrition and weight management. Most of the studies showed no clinical evidence for gene-based personalised nutrition. The Food4Me study, e.g., investigated four different groups of personalised dietary recommendations based on dietary guidelines, and physiological, clinical, or genetic parameters, and resulted in no difference in weight loss between the levels of personalisation. Furthermore, genetic direct-to-consumer (DTC) tests are widely spread by companies. Scientific organisations clearly point out that, to date, genetic DTC tests are without scientific evidence. To date, gene-based personalised nutrition is not yet applicable for the treatment of obesity. Nevertheless, personalised dietary recommendations on the genetic landscape of a person are an innovative and promising approach for the prevention and treatment of obesity. In the future, human intervention studies are necessary to prove the clinical evidence of gene-based dietary recommendations.

Personal genomic testing for nutrition and wellness in Australia: A content analysis of online information

AIM

Personal genomic testing for nutrition and wellness (PGT-NG) offers a new service delivery model to nutritionists and dietitians. However, research indicates that this type of testing currently lacks sufficient clinical validity and utility to be commercially available. Despite Australian guidelines to the contrary, healthcare professionals are currently offering testing to clients, and promoting these services online. Thus, it is important to understand how PGT-NG is currently framed online to the public.

METHODS

A mixed methods content analysis was conducted to assess the content, quality and marketing approaches of websites offering PGT-NG to Australians. Websites were identified using popular search engines to mimic the behaviour of a consumer. A novel framework was developed for the purposes of the analysis.

RESULTS

Thirty-nine websites were analysed, comprising four nutritional genomic testing company websites and 35 healthcare provider websites. Healthcare providers relied on information from the testing companies. The content was emotive, and little attention was given to the scientific and ethical aspects of personal genomic testing. Websites appealed to consumer empowerment and framed testing as an essential and superior tool for optimising health.

CONCLUSIONS

Websites lacked the transparency necessary for informed consent. A basic checklist of key information was developed to aid healthcare providers when informing potential clients of PGT-NG online.

The Evolution of Public Health Genomics: Exploring Its Past, Present, and Future

Public health genomics has evolved to responsibly integrate advancements in genomics into the fields of personalized medicine and public health. Appropriate, effective and sustainable integration of genomics into healthcare requires an organized approach. This paper outlines the history that led to the emergence of public health genomics as a distinguishable field. In addition, a range of activities are described that illustrate how genomics can be incorporated into public health practice. Finally, it presents the evolution of public health genomics into the new era of "precision public health."

Personalised nutrition and health

Jose Ordovas and colleagues consider that nutrition interventions tailored to individual characteristics and behaviours have promise but more work is needed before they can deliver

Proposed guidelines to evaluate scientific validity and evidence for genotype-based dietary advice

Nutrigenetic research examines the effects of inter-individual differences in genotype on responses to nutrients and other food components, in the context of health and of nutrient requirements. A practical application of nutrigenetics is the use of personal genetic information to guide recommendations for dietary choices that are more efficacious at the individual or genetic subgroup level relative to generic dietary advice. Nutrigenetics is unregulated, with no defined standards, beyond some commercially adopted codes of practice. Only a few official nutrition-related professional bodies have embraced the subject, and, consequently, there is a lack of educational resources or guidance for implementation of the outcomes of nutrigenetic research. To avoid misuse and to protect the public, personalised nutrigenetic advice and information should be based on clear evidence of validity grounded in a careful and defensible interpretation of outcomes from nutrigenetic research studies. Evidence requirements are clearly stated and assessed within the context of state-of-the-art 'evidence-based nutrition'. We have developed and present here a draft framework that can be used to assess the strength of the evidence for scientific validity of nutrigenetic knowledge and whether 'actionable'. In addition, we propose that this framework be used as the basis for developing transparent and scientifically sound advice to the public based on nutrigenetic tests. We feel that although this area is still in its infancy, minimal guidelines are required. Though these guidelines are based on semi-quantitative data, they should stimulate debate on their utility. This framework will be revised biennially, as knowledge on the subject increases.

Ethical issues in the development and implementation of nutrition-related public health policies and interventions: A scoping review

Background

The limited integration of ethics in nutrition-related public health policies and interventions is one major concern for those who have the task of implementing them. Ethical challenges that are overlooked during the development of such interventions could raise serious ethical issues during their implementation and even after. As a result, these decision makers need technical support and ethical guidance for adaptation of interventions to local (cultural, social, economic, etc.) contexts.

Aim

The goal of this scoping review is to delineate and “map” the range of ethical issues in nutrition-related public health interventions, as well as the range of the various fields in which they may arise.

Methods

A scoping review of empirical research and conceptual literature was conducted following the framework of Arksey and O’Malley. Searches using PubMed with Medical Subject Headings (MeSH) categories and Advanced Search Builder as well as in the Global Health Library were performed. The final sample consists of 169 publications.

Results

The ethics of public health prevention or treatment of obesity and non-communicable diseases is the most explicitly and frequently discussed subject. In comparison, ethical issues raised by public health interventions in the fields of undernutrition, breastfeeding, vitamin/mineral supplementation and food fortification, food security, food sustainability and food safety are addressed in a lower proportion of the sample. The results illustrate the various natures, types, and scopes of existing public health nutrition-related interventions, and the various ethical issues that may be raised by these interventions, in addition to the numerous and different contexts in which they may be implemented.

Discussion

The ethical issues faced in the development and implementation of nutrition-related public health interventions are varied and cannot be equated with, nor generalized about, when dealing with specific activities in this field. More importantly, these ethical issues cannot be managed without a careful consideration for the complexity of contexts in which nutrition-related interventions are expected to be implemented. These interventions engage a variety of actors with diverse perspectives and interests. We discuss these challenges and also comment on the importance of considering ethical impacts in the monitoring and evaluation of such interventions.

Conclusion

General ethical frameworks or recommendations–although useful–cannot be expected to provide policy makers, implementators and other public health personnel with sufficient practical ethical guidance as they cannot consider and anticipate the particularities of all specific nutrition-related public health interventions and the complexity of the contexts in which they are implemented. Further research is needed in order to develop more targeted ethical frameworks.

Nature, Nurture, and Cancer Risks: Genetic and Nutritional Contributions to Cancer

It is speculated that genetic variants are associated with differential responses to nutrients (known as gene-diet interactions) and that these variations may be linked to different cancer risks. In this review, we critically evaluate the evidence across 314 meta-analyses of observational studies and randomized controlled trials of dietary risk factors and the five most common cancers (breast, lung, prostate, colorectal, and stomach). We also critically evaluate the evidence across 13 meta-analyses of observational studies of gene-diet interactions for the same cancers. Convincing evidence for association was found only for the intake of alcohol and whole grains in relation to colorectal cancer risk. Three nutrient associations had highly suggestive evidence and another 15 associations had suggestive evidence. Among the examined gene-diet interactions, only one had moderately strong evidence.