Ethical issues raised by personalized nutrition based on genetic information

Precision or Personalized Nutrition: A Bibliometric Analysis

Food systems face the challenge of maintaining adequate nutrition for all populations. Inter-individual responses to the same diet have made precision or personalized nutrition (PN) an emerging and relevant topic. The aim of this study is to analyze the evolution of the PN field, identifying the principal actors and topics, and providing a comprehensive overview. Therefore, a bibliometric analysis of the scientific research available through the Web of Science (WOS) database was performed, revealing 2148 relevant papers up to June 2024. VOSviewer and the WOS platform were employed for the processing and analysis, and included an evaluation of diverse data such as country, author or most frequent keywords, among others. The analysis revealed a period of exponential growth from 2015 to 2023, with the USA, Spain, and England as the top contributors. The field of "Nutrition and Dietetics" is particularly significant, comprising nearly 33% of the total publications. The most highly cited institutions are the universities of Tufts, College Dublin, and Navarra. The relationship between nutrition, genetics, and omics sciences, along with dietary intervention studies, has been a defining factor in the evolution of PN. In conclusion, PN represents a promising field of research with significant potential for further advancement and growth.

Genetic test for the prescription of diets in support of physical activity

Owing to the fields of nutrigenetics and nutrigenomics today we can think of devising approaches to optimize health, delay onset of diseases and reduce its severity according to our genetic blue print. However this requires a deep understanding of nutritional impact on expression of genes that may result in a specific phenotype. The extensive research and observational studies during last two decades reporting interactions between genes, diet and physical activity suggest a cross talk between various genetic and environmental factors and lifestyle interventions. Although considerable efforts have been made in unraveling the mechanisms of gene-diet interactions the scientific evidences behind developing commercial genetic tests for providing personalized nutrition recommendations are still scarce. In this scenario the current mini-review aims to provide useful insights into salient feature of nutrition based genetic research and its commercial application and the ethical issue and concerns related to its outcome.

Ethical considerations in the implementation of nutrigenetics/nutrigenomics

Awareness of ethical issues that may be raised by the implementation of nutrigenetic/nutrigenomic (NGx) testing and personalized nutrition, at an individual or a public health level, is crucial to ensure the latter's sound and effective implementation. NGx tests that are currently offered or developed have different natures and scopes. We provide an example of NGx testing on the MTHFR gene to illustrate the current challenges when it comes to grasp the meaning of the results of such testing. In addition, NGx testing is developed within an evolving landscape of new genomic technologies and occurs at a time when public health policies mainly focus on preventive and predictive healthcare, with an emphasis on increased individual responsibility. The ethical issues raised by such a context and the genetic nature of NGx testing both should be carefully evaluated.

Guide and Position of the International Society of Nutrigenetics/Nutrigenomics on Personalized Nutrition: Part 2 - Ethics, Challenges and Endeavors of Precision Nutrition

Nutrigenetics considers the influence of individual genetic variation on differences in response to dietary components, nutrient requirements and predisposition to disease. Nutrigenomics involves the study of interactions between the genome and diet, including how nutrients affect the transcription and translation process plus subsequent proteomic and metabolomic changes, and also differences in response to dietary factors based on the individual genetic makeup. Personalized characteristics such as age, gender, physical activity, physiological state and social status, and special conditions such as pregnancy and risk of disease can inform dietary advice that more closely meets individual needs. Precision nutrition has a promising future in treating the individual according to their phenotype and genetic characteristics, aimed at both the treatment and prevention of disease. However, many aspects are still in progress and remain as challenges for the future of nutrition. The integration of the human genotype and microbiome needs to be better understood. Further advances in data interpretation tools are also necessary, so that information obtained through newer tests and technologies can be properly transferred to consumers. Indeed, precision nutrition will integrate genetic data with phenotypical, social, cultural and personal preferences and lifestyles matters to provide a more individual nutrition, but considering public health perspectives, where ethical, legal and policy aspects need to be defined and implemented.

Risks of nutrigenomics and nutrigenetics? What the scientists say

Nutrigenomics and nutrigenetics (hereafter NGx) have stimulated expectations for beneficial applications in public health and individuals. Yet, the potential achievability of such promise is not without socioethical considerations that challenge NGx implementation. This paper focuses on the opinions of NGx researchers about potential risks raised by NGx. The results of an online survey show that these researchers (n = 126) are fairly confident about the potential benefits of NGx, and that most downplay its potential risks. Researchers in this field do not believe that NGx will reconfigure foods as medication or transform the conception of eating into a health hazard. The majority think that NGx will produce no added burden on individuals to get tested or to remain compliant with NGx recommendations, nor that NGx will threaten individual autonomy in daily food choice. The majority of researchers do not think that NGx will lead to discrimination against and/or stigmatization of people who do not comply with NGx dietary recommendations. Despite this optimism among NGx researchers, we suggest that key risk factors raised by the socioethical context in which NGx applications will be implemented need to be considered.

Do we know enough? A scientific and ethical analysis of the basis for genetic-based personalized nutrition

This article discusses the prospects and limitations of the scientific basis for offering personalized nutrition advice based upon individual genetic information. Two divergent scientific positions are presented, with an ethical comment. The crucial question is whether the current knowledge base is sufficiently strong for taking an ethically responsible decision to offer personalized nutrition advice based upon gene-diet-health interaction. According to the first position, the evidence base for translating the outcomes of nutrigenomics research into personalized nutritional advice is as yet immature. There is also limited evidence that genotype-based dietary advice will motivate appropriate behavior changes. Filling the gaps in our knowledge will require larger and better randomized controlled trials. According to the second position, personalized nutrition must be evaluated in relation to generally accepted standard dietary advice-partly derived from epidemiological observations and usually not proven by clinical trials. With personalized nutrition, we cannot demand stronger evidence. In several specific cases of gene-diet interaction, it may be more beneficial for individuals with specific genotypes to follow personalized advice rather than general dietary recommendations. The ethical comment, finally, considers the ethical aspects of deciding how to proceed in the face of such uncertainty. Two approaches for an ethically responsible way forward are proposed. Arguing from a precautionary approach, it is suggested that personalized dietary advice should be offered only when there is strong scientific evidence for health effects, followed by stepwise evaluation of unforeseen behavioral and psychological effects. Arguing from theoretical and applied ethics as well as psychology, it is also suggested that personalized advice should avoid paternalism and instead focus on supporting the autonomous choice of each person.

Editorial

This special section of Genes and Nutrition presents a baseline analysis of ethical and legal issues undertaken within the EU FP7 research project Food4Me, which investigates the feasibility today of the vision for delivering personalized nutrition. Four major topics are addressed: Do we know enough for offering personalized nutritional advice? How can personal, cultural, and scientific perspectives on food and health be integrated? How does personalized nutrition affect individual autonomy? Which urgent ethical and legal matters stand out when personalized nutrition is commercialized?

Values at stake: autonomy, responsibility, and trustworthiness in relation to genetic testing and personalized nutrition advice

Personalized nutrition has the potential to enhance individual health control. It could be seen as a means to strengthen people's autonomy as they learn more about their personal health risks, and receive dietary advice accordingly. We examine in what sense personalized nutrition strengthens or weakens individual autonomy. The impact of personalized nutrition on autonomy is analyzed in relation to responsibility and trustworthiness. On a societal level, individualization of health promotion may be accompanied by the attribution of extended individual responsibility for one's health. This constitutes a dilemma of individualization, caused by a conflict between the right to individual freedom and societal interests. The extent to which personalized nutrition strengthens autonomy is consequently influenced by how responsibility for health is allocated to individuals. Ethically adequate allocation of responsibility should focus on prospective responsibility and be differentiated with regard to individual differences concerning the capacity of adults to take responsibility. The impact of personalized nutrition on autonomy also depends on its methodological design. Owing to the complexity of information received, personalized nutrition through genetic testing (PNTGT) is open to misinterpretation and may not facilitate informed choices and autonomy. As new technologies, personalized nutrition and PNTGT are subject to issues of trust. To strengthen autonomy, trust should be approached in terms of trustworthiness. Trustworthiness implies that an organization that develops or introduces personalized nutrition can show that it is competent to deal with both the technical and moral dimensions at stake and that its decisions are motivated by the interests and expectations of the truster.

Food and health: individual, cultural, or scientific matters?

In personalized nutrition, food is a tool for good health, implying an instrumental relationship between food and health. Food receives a secondary value, while health would appear to be a descriptive biological concept. This article gives an introduction to cultural understandings of food and health. The wider definition of food and health is explored in relation to the commonly used scientific approach that tends to take a more reductionist approach to food and health. The different discourses on food and health are being discussed in relation to ethical aspects of personalized nutrition. The success of personalized nutrition is likely dependent upon the ability to integrate the scientific approach with everyday cultural, emotional, ethical, and sensual understandings of food. Health theories can be divided into two principal rival types-biostatistical and holistic. Biostatistical focuses on survival, while holistic focuses on ability as a precondition for health. Arguments in favor of a holistic and individualistic theory of health and illness are presented. This implies a focus on the ability of the individual to realize his or her "vital goals." A holistic and individualistic health concept may have a reinforcing effect on the individualized approach in personalized nutrition. It allows focus on individual health premises and related dietary means of health promotion, as well as an individualized perspective on the objectives of health promotion. An individualistic notion of health also indicates that people with high levels of vital goals benefit more easily. To reach beyond these groups is likely difficult. This potential injustice should be balanced with global preventive medical programs.

The challenges for molecular nutrition research 1: linking genotype to healthy nutrition

Nutrition science finds itself at a major crossroad. On the one hand we can continue the current path, which has resulted in some substantial advances, but also many conflicting messages which impair the trust of the general population, especially those who are motivated to improve their health through diet. The other road is uncharted and is being built over the many exciting new developments in life sciences. This new era of nutrition recognizes the complex relation between the health of the individual, its genome, and the life-long dietary exposure, and has lead to the realisation that nutrition is essentially a gene-environment interaction science. This review on the relation between genotype, diet and health is the first of a series dealing with the major challenges in molecular nutrition, analyzing the foundations of nutrition research. With the unravelling of the human genome and the linking of its variability to a multitude of phenotypes from "healthy" to an enormously complex range of predispositions, the dietary modulation of these propensities has become an area of active research. Classical genetic approaches applied so far in medical genetics have steered away from incorporating dietary effects in their models and paradoxically, most genetic studies analyzing diet-associated phenotypes and diseases simply ignore diet. Yet, a modest but increasing number of studies are accounting for diet as a modulator of genetic associations. These range from observational cohorts to intervention studies with prospectively selected genotypes. New statistical and bioinformatics approaches are becoming available to aid in design and evaluation of these studies. This review discusses the various approaches used and provides concrete recommendations for future research.

Patients, evidence and genes: an exploration of GPs' perspectives on gene-based personalized nutrition advice

BACKGROUND

Nutrigenomics science examines the response of individuals to food compounds using post-genomics technology. It is expected that in the future, personalized nutrition advice can be provided based on information about genetic make-up.

OBJECTIVES

Gene-based personalized nutrition advice emerges at the junction of different disciplines and technologies and may directly influence people's lives. Therefore, public concern is to be expected. Because GPs are gatekeepers of health care, their involvement in early stages of the development process is desirable.

METHOD

In 2006, 15 GPs were interviewed to collect their perceived barriers and opportunities towards involvement in gene-based nutrition advice. The interviews were qualitatively analysed with use of Atlas.ti, a qualitative analysis programme.

RESULTS

The participants held a mostly critical view towards such personalized nutrition advice. They argued that findings of nutritional studies lacked robustness, were not based on patients' needs and were often equivocal. And that a patient central perspective urges them to question consequences for patients. Participants argued that GPs should be involved in selecting and monitoring patients in nutrigenomics studies.

CONCLUSIONS

Early involvement of GPs in the development process is needed to allow for the integration of their practical, social and ethical considerations in the technical and scientific agendas. However, the background of their critical attitude towards nutrigenomics-based personalized nutrition, and nutrition advice more generally, has to be explored further. To facilitate a joint learning process and to improve socio-technical decision making with respect to this innovation, initiatives that allow different stakeholders to exchange their perspectives should be organized.

Integrating anticipated nutrigenomics bioscience applications with ethical aspects

Nutrigenomics is a subspecialty of nutrition science which aims to understand how gene-diet interactions influence individuals' response to food, disease susceptibility, and population health. Yet ethical enquiry into this field is being outpaced by nutrigenomics bioscience. The ethical issues surrounding nutrigenomics face the challenges of a rapidly evolving field which bring forward the additional dimension of crossdisciplinary integrative research between social and biomedical sciences. This article outlines the emerging nutrigenomics definitions and concepts and analyzes the existing ethics literature concerning personalized nutrition and presents "points to consider" over ethical issues regarding future nutrigenomics applications. The interest in nutrigenomics coincides with a shift in emphasis in medicine and biosciences toward prevention of future disease susceptibilities rather than treatment of already established disease. Hence, unique ethical issues emerge concerning the extent to which nutrigenomics can alter our relation to food, boundaries between health and disease, and the folklore of medical practice. Nutrigenomics can result in new social values, norms, and responsibilities for both individuals and societies. Nutrigenomics is not only another new application of "-omics" technologies in the context of gene-diet interactions. Nutrigenomics may fundamentally change the way we perceive human illness while shifting the focus and broadening the scope of health interventions from patients to healthy individuals. In resource- and time-limited healthcare settings, this creates unique ethical dilemmas and distributive justice issues. Ethical aspects of nutrigenomics applications should be addressed proactively, as this new science develops and increasingly coalesces with other applications of genomics in medicine and public health.

Evidence-based management of nutrigenomics expectations and ELSIs

Nutrigenomics is a new application context for genomics technologies that focuses on the bidirectional study of genetic factors influencing host (individuals' or populations') response to diet and the effects of bioactive constituents in food on host genome and gene expression. Nutrigenomics is considered the next wave after pharmacogenomics for individualization of health interventions. However, relatively little attention has been given to the specific ethical-legal-social issues (ELSIs) and sociotechnical expectations raised by nutrigenomics research. Some of the ELSIs, such as ensuring privacy of genetic information and implications of genetic testing for health insurance and employment, may be shared across the continuum of genomic technology applications in human disease genetics, pharmacogenomics and nutrigenomics. However, there are certain aspects of nutrigenomics research that may result in unique or unprecedented ELSIs. For example, nutrigenomics has a strong focus on public health and the prevention/modification of 'predisease phenotypes' in apparently healthy individuals. Thus, in contrast to previous applications of genomics technologies, where the goal is to distinguish existing disease from absence of disease, the aim of nutrigenomics is the discernment of nuanced differences in predisease states. Moreover, there is evidence to suggest that ELSIs may be different in biomarker discovery, translational research and clinical testing stages of nutrigenomics. Ideally, ELSI research and nutrigenomics bioscience should progress in parallel and in a commensurate manner. We suggest that qualitative research methods, using a hypothesis-free approach, can be employed to gain deeper insights on complex bioethics issues that do not ordinarily lend themselves to formal hypothesis testing with the quantitative methods used in biomedical sciences.