Background: The past two decades have seen exponential growth in the number of genetic testing companies, but only a small percentage of these tests are being sold through health care professionals (HCPs). As each new genetic testing company appears, it is becoming more difficult for the practitioner and consumer to evaluate the credibility of the claims being made and the value of the tests being offered. Summary: HCPs appear to have minimal nutrigenomics knowledge and little confidence in choosing and interpreting nutrigenetic tests. To remedy this, HCPs need access to credible education, professional support, networking, career development, mentorship, and a regulated testing environment. This will enable them to evaluate the credibility of genetic tests and testing companies, provide genetic results in context, and apply appropriate clinical translation. Key Message: In order to establish an expert group of nutrigenomic practitioners, collaboration is required between educational institutions, professional organizations, and genetic testing companies. This will provide the necessary support, skills, and knowledge to ensure that the best value is extracted from nutrigenetic tests in an ethical and responsible manner.
A great deal has changed in the nutrigenetic (NGX) testing environment since the first NGX tests appeared in the early 2000s. The past two decades have seen exponential growth in the number of genetic testing companies in the market place . As each new genetic testing company appears, it is becoming more and more difficult for the practitioner and consumer to evaluate the credibility of the claims being made and the value of the tests being offered.
Media and industry reports have focused on the growth from direct-to-consumer (DTC) NGX tests, but what is missing from this conversation is the use of practitioner-based NGX tests and the role of the health professional in their execution. Only a small percentage of genetic tests are being sold through health care professionals (HCPs), yet countless publications have identified the health professional as key to the delivery and translation of NGX tests . In a recent article by Bush et al. , they propose that personalized nutrition should be used by various HCPs at different levels, and thus training and education should be appropriate to the level of application. Educational courses and curricula, training programs, and certification standards should continuously be developed to ensure progressive and up-to-date offerings .
This commentary does not attempt to review the state of the nutrigenomic science, nor offer an opinion as to whether the science is ready for clinical use. These tests are already being used by consumers and clinicians. It is important for health science academics, HCP organizations and associations, and the genetic testing industry to understand the reasons HCPs are choosing or not choosing to utilize NGX tests in their practice. How clinicians experience nutrigenomics will be influenced by the peer-reviewed research they have been exposed to, their academic environment in gaining their qualifications, and their exposure to the genetic testing industry and thereby understand what it will take to build an expert group of nutrigenomic practitioners .
This article explores the possibility that HCPs have not been adequately up-skilled and supported in working in this area, nor do they feel confident in being able to select and utilize an NGX test. The following areas have been identified for the role they play in enabling and developing nutrigenomic practitioners.
Competency and confidence of the HCP.
Nutrigenomic education opportunities.
Professional development and support.
NGX test selection.
Competency and Confidence of the HCP
In 2005, the UK Human Genetics Commission published their principles for the provision of genetic testing services directly (or indirectly) to the consumer . They identify the health professional as the appropriate candidate to interpret and translate genetic tests. They recommend “an appropriately qualified professional, with recognized training and qualifications, employed by or representing the test provider, who is regulated by an appropriate professional body, should be responsible for ensuring that consumers are provided with all of the information specified in this section of the Principles.” However, when surveyed, HCPs exhibit a poor knowledge of genetics and nutrigenomics, little confidence in their ability to work with genetic tests, but a willingness to increase their knowledge. Despite the fact that genetic tests are used by nutritionists, homeopaths, medical doctors, specialists, nurse practitioners, physician assistants, and chiropractors, research detailed below has focused almost exclusively on dietitians.
Horne et al.  explored the attitude and knowledge of third-year dietetic students from Brescia University College in Canada. The authors found that the undergraduate students had limited knowledge of genetic testing, stating that they had “no idea” what nutrigenomics was. They did, however, show a strong interest in attending undergraduate or postgraduate courses . In another Canadian HCP study, it was found that only half of the participants were familiar with the term nutrigenomics .
Amongst UK dietitians, there was an overall low confidence and involvement in nutrigenomics . Interestingly, 51% of respondents reported no involvement in consulting on diseases that have both dietary and genetic components, despite working with obesity, diabetes, and cardiovascular disease, all polygenetic conditions harboring both dietary and genetic components .
The USA Human Genome Education Model Project (HuGEM) was administered amongst six different health professions including dietitians, occupational therapists, physical therapists, psychologists, speech-language-hearing specialists, and social workers . They reported inadequate knowledge and confidence to provide genetic services to their patients and a strong desire for further genetic education . An international cross-sectional study including 1,844 dietitians from Australia (n = 390), USA (n = 461), and the UK (n = 993) found that the majority of participants had low clinical and educational confidence in nutrigenomics across the board .
These studies confirm that HCPs have a low knowledge base for nutrigenomics and little confidence in being able to choose a commercial test and interpret it for their patients . This highlights the provision of NGX education as an important starting point to address the perceived lack of competency and inadequate knowledge .
Nutrigenomic Education Opportunities
Despite the considerable growth in the publication of NGX peer-reviewed journal articles and the increasing presence of NGX in conference programs around the world, NGX course content in undergraduate curricula remains minimal. Prasad et al.  suggest that what is required is a systematic incorporation of the teaching of nutritional genomics and associated legal, social, and ethical issues in the undergraduate curricula of health sciences. They suggest that the greatest obstacle to this is that the curricula are filled with mandated graduation requirements, making the addition of a stand-alone course in nutritional genomics challenging to most universities .
The last decade has, however, seen an increase in the number of postgraduate degrees, university courses, online programs, and workshops in NGX offered by various universities, commercial companies, and health care institutes . A number of these education opportunities have been described in Table 1. Courses were selected for inclusion by performing a literature search making use of electronic databases; PubMed, Google, and Google Scholar. The following search terms were used: nutrigenomics, nutrigenetics, education, courses, tertiary, commercial, health practitioners, curriculum, undergraduate nutritional education, postgraduate nutritional education, tertiary institutes, target audience, online courses, and workshops. No date and location limit was placed on the literature research. Articles that were cited and mentioned by review articles were also included and used to identify the relevant courses added to the tables. The search was limited to courses provided in English as the manuscript is being published in English and the authors are English speaking and unable to adequately evaluate courses in other languages; however, we acknowledge the fact that there are many courses offered in other languages around the world. Notably, there are a number of nutrigenomics courses offered in French including: NUT-7010 Nutrigénomique offered by Laval University (Québec), NUT 6033 – Nutrigénomique offered by the University of Montréal (Québec), NUT 3705 Introduction à la génomique nutritionnelle offered by the University of Ottawa (Ottawa), and About Kids Health’s course in Nutrigénomique (Toronto).
Courses which focused on undergraduate and postgraduate nutrition students, nutrition scientists, and health care practitioners, especially nutrition HCPs, were included. Tertiary courses or modules that formed part of the curriculum for undergraduate nutrition, science, or biology degrees were included in Table 1a, as well as postgraduate courses that formed part of the curriculum for nutrition and health science MSc or PhD degrees. Tertiary and online courses focusing on the translation, application, and clinical use of nutrigenomics were included in Table 1a, b. Training workshops focusing on enabling HCPs to apply nutrigenomics in their practices were included in Table 1b.
Although there has been an increase in the NGX programs offered, they differ in cost, duration, content, and the scientific rigor on which they have been built. This makes it difficult for the HCP to choose the best program to meet their needs . Many of the university programs offered, especially the doctoral postgraduate programs, focus on research, with little or no instruction in clinical translation. The HCP therefore relies on continuing education offered by affiliated associations or commercial organizations to enable clinical translation [12-14]. A number of practitioner-based genetic testing companies have addressed this knowledge gap by providing NGX education in one form or another to their practitioners to better equip them to provide NGX services to their patients . In addition to the formal and informal education described in Table 1, the minimum that is required is the introduction of adequate NGX and nutrigenomic education in HCP undergraduate curricula. This will require collaboration between health science universities, health professional associations, and certification and accreditation bodies.
Professional Development and Support
Professional associations and organizations serve the purpose of growing the whole profession as well as the individual HCP. They commonly address networking, education, career development, and mentorship, and in some cases involve themselves in certification and regulation. In the field of nutrigenomics, the European Nutri-genomics Organization, an Association of Universities and Research Institutes (NuGO) and the International Society of Nutrigenetics and Nutrigenomics (ISNN) have historically taken the lead in professional development; however, little has been done in accreditation, certification, and regulation. Recently, the American Nutrition Association (ANA) has begun to address this requirement. Below is a brief description of each organization and their contribution to the field.
NuGO is an association of 27 universities and research institutes that focus on research in molecular nutrition, personalized nutrition, nutrigenomics, and nutritional systems biology. NuGO evolved from an EU Sixth Framework Network of Excellence that ended in 2010, and the association took over some of the activities as well as developing new ones and expanding beyond Europe. The network aims to facilitate research, education, communication, and dissemination, at the interface of nutrigenomics with nutrition and health. One of their main objectives is the development, data-warehousing, and exploitation of nutrition- and health-related bioinformatics for the benefit of European nutrition researchers, and for the community as a whole.
The ISNN was established in 2005. The purpose of the society is to increase the understanding of the role of genetic variation and individual dietary response, and the role of nutrients in gene expression. This is done through research and education of professionals and the general public. They offer annual conferences, disseminate evidence-based information to the public, develop recommendations for the use of nutrigenomics in practice, and provide training in omics-based precision nutrition practice for health professionals.
ANA/Board for Certified Nutrition Specialists
The ANA has been a leader in the education of nutrition professionals for some time. More recently they have been highlighting the role of NGX in nutrition science and are in the process of developing a nutritional genomics training program which will be offered to clinicians such as nutritionists, dietitians, and other licensed HCPs who have advanced training in biochemistry, nutritional assessment, and therapeutics.
These organizations are favorably contributing to the establishment of NGX as a credible clinical offer. There are, however, health professional organizations that have not as yet contributed to the nutrigenomics conversation. In addition, there is a great deal of work that needs to be done around tertiary education, scope of practice for HCPs, accreditation, and certification. In addition to the requirements for clinicians, it is imperative that a regulatory environment be put in place to manage the proliferation of NGX tests in the market place.
NGX Test Selection
It is important that HCPs who use NGX tests are equipped with the appropriate knowledge and confidence to offer nutrigenomic advice to their patients. Their challenge, however, is in choosing the best commercially available NGX test to work with in their practice. There is variability in the methodology and rigor driving NGX test development and execution [15-17] and HCPs need to be able to critically evaluate these tests.
There are a number of variables that determine the credibility and clinical usefulness of a genetic testing company. HCPs need to actively engage with these companies, starting with an understanding of what criteria were used to select the gene variants included in the test. Researchers and various private and public organizations have developed methods for evaluating genetic tests in clinical settings, to guide the proper translation of genomics into clinical practice . The main evaluation method for assessing the performance of genetic tests from the laboratory to clinical practice is the ACCE model, which stands for the four evaluation criteria; analytic validity, clinical validity, clinical utility, and ethical, legal, and social implications . While ACCE is used the most, additional frameworks include:
The Health Technology Assessment (HTA) .
Wilson and Jungner screening criteria [20, 21].
The Evaluation of Genomic Application in Practice and Prevention Framework (EGAPP) .
The Genetic Testing Evidence Tracking Tool (GETT) .
The McMaster University Evaluation Framework .
The Frueh and Quinn Framework [16, 25, 26].
The three commonalities between these methods are the evaluation of analytical validity, clinical validity, and clinical/health utility. These are defined as follows:
Analytical validity refers to the ability of a genetic test to accurately test for gene variants of interest in samples that are representative of the population of interest. It also includes analytic sensitivity, analytic specificity, laboratory precision, and assay robustness [25, 27].
Clinical validity focusses on the reliable and accurate prediction of the clinical disorder or phenotype under examination. Clinical validity can also be conveyed as a measure of association, for instance in the case were odds ratios are given [25, 27].
Clinical/health utility is the confirmation that a certain genetic test measurably improves health outcomes and adds value to the decisions and lifestyle changes patients make in comparison to health management without the use of genetic testing [25, 27].
Most tests will address the first two, but few are able to define how the gene variants chosen achieve clinical or health utility. In a clinical translational environment, this is imperative. If the use of an NGX test does not contribute to the HCPs clinical decision-making, then it is an expensive test with little clinical value. In addition to validity and utility, many of the evaluation methods also focus on criteria that contribute to the quality of the testing experience, including [25, 27-29]:
Ethical, legal, and social implications.
The compliance of laboratories to an acceptable quality standard.
Purpose and appropriateness of the genetic test.
Whether appropriate NGX counseling for the specific type of test and disease are provided.
The privacy, security, and confidentiality of genetic information.
Avoidance of inappropriate testing of minors and other legally incapacitated individuals.
The transparency of genes tested and claims made.
Not included in these evaluation methods is an understanding of the scientific rationale for the development of test report recommendations [2, 27]. In a recent commentary by Loos , she points out that there are a number of problems inherent in DTC genetic tests. Many of these have also been observed in practitioner-based test reports and impact test report recommendations . They include:
Making claims based on testing only a single or few gene variants.
Making diet, lifestyle, or supplement recommendations based on a single (low penetrance) gene variant.
Promoting the common misconception that an NGX gene variant can predict disease.
Basing gene variant selection on association and interaction studies without consideration for biological plausibility and biochemical function.
Taking genetics out of context when giving diet and lifestyle advice.
Providing HCPs with the ability to critically evaluate an NGX test and to interrogate the company offering the test is as important as being taught the molecular principles of NGX and nutrigenomics. This is an area where regulatory guidelines are required to ensure credibility and accountability in the industry.
Until such time as a comprehensive nutrigenomic solution is made available to health professionals, consumers will continue to be drawn to DTC companies. In order to establish an expert group of nutrigenomic practitioners, collaboration is required between educational institutions, professional organizations, and genetic testing companies. Health professionals need adequate knowledge to be able to evaluate the credibility of genetic tests being offered [27, 31, 32]. They need to provide genetic results in context, base their knowledge on evidence-based learning, and apply clinical translation. They need to be provided with appropriate mentorship and form part of a community. Together, this will provide the necessary support, skills, and knowledge to ensure that the best value is extracted from NGX tests in an ethical and responsible manner.
Yael Joffe and Heléne Herholdt are employed by 3X4 Genetics and Manuka Science.
Yael Joffe and Heléne Herholdt contributed equally in the conception, design, and writing. Yael Joffe was responsible for final approval of the version to be published.