Nutrigenomics: perceptions of South African dietitians and general practitioners

Abstract

Background: Nutrigenomics is defined as the study of how nutrients affect gene function. The primary objective of the field of nutrigenomics is to improve health through dietary recommendations aimed at subgroups of populations in which current general recommendations may not be relevant. If health care workers can promote healthy dietary behaviour based on results of genetic testing provided by nutrigenomic services, this can help to address non-communicable diseases (NCDs) and other diseases more effectively. Currently, no studies related to the perceptions of registered dietitians (RDs) and general practitioners (GPs) regarding nutrigenomics in South Africa (SA) are available. In view of the lack of information in SA and conflicting information from other countries about the feasibility of using nutrigenomics in practice, the purpose of the current study was to investigate the perceptions of RDs and GPs in SA regarding nutrigenomics. The perceptions of RDs and GPs were compared, and associations between background regarding nutrigenomics and perceptions determined. The Health Sciences Research Ethics Committee (UFS-HSD2020/0112/2403) of the University of the Free State provided approval to conduct this study. Methods: A self-administered electronic survey was used to collect the information required for this study. The survey was distributed in English. The survey consisted of open- and close-ended questions. Responses were rated according to a dichotomous response set, as well as a four-point scale. Recruitment of participants was undertaken via the Association for Dietetics in SA (ADSA) and social media platforms. Potential participants were informed about the study and invited to participate, using convenience and snowball sampling methods. Participation was encouraged by sending out a reminder to targeted participants two weeks after the initial invitation. Results: The sample included 150 RDs and 23 GPs. Majority of RDs (97.3%) and 30.4% of GPs had heard the term ‘nutrigenomics’ before. Almost three-quarters of RDs and GPs had or would personally consider genetic testing. More than half of RDs (58.9%) and only two (8.7%) GPs had read scientific literature relating to nutrigenomics during the past year. About a third (32.0%) of RDs and only three (13.0%) GPs had provided nutrigenomic counselling to patients during the past year. Both RDs (46.3%) and GPs (52.2%) rated genetic testing as ‘important’, while the majority of RDs (92.0%) and GPs (95.7%) rated nutrition as ‘very important’ in the medical or health industry. RDs ranked private companies (direct-to-consumer genetic testing companies) as most equipped (43.5%), while GPs ranked RDs as most equipped (31.8%) to provide nutrigenomic counselling. There was a statistically significant difference between RDs and GPs in terms of the ranking of how equipped dietitians are to provide nutrigenomic services (p=0.0345). Dietitians were rated by GPs as equipped to very equipped, while RDs rated themselves as neutral to equipped to deliver nutrigenomic counselling. More than half of RDs strongly agreed with all consumer motivators to make use of nutrigenomic services (motivated by a desire to prevent or manage disease, prevent a disease based on family history, control health outcomes based on family history, and improve overall health-related quality of life). Only about a third of GPs strongly agreed with almost all the consumer motivators, the exception being to ‘prevent a disease based on family history’ where more than half of GPs strongly agreed. About three-quarters of participants rated cost concerns as the greatest barrier to implementing nutrigenomic testing. The lowest-ranked barriers to implementation were confidentiality issues (40.0% for RDs and 60.9% for GPs) and moral concerns (37.3% for RDs and 47.8% for GPs). RDs perceived ‘greater individualisation of diet prescription (personal nutrition)’ (68.7%), and GPs perceived ‘strongest foundations for nutrition recommendations’ (60.9%) as the greatest possible benefits. More than half of RDs and only about a third of GPs reported that they would change the usual care or service that they provide based on new knowledge about nutrigenomics. Conclusions: Findings of the study were mostly consistent with previous research which found that although considered to be important, RDs and GPs felt that the emerging field of nutrigenomics needs further development before it can be widely applied effectively in routine private and public health care in SA. Recommendations: This study identified the need to add or expand the field of nutrigenomics in the current undergraduate curriculum of South African universities. Additional training on the planning of personalised diets and data interpretation tools are required to prepare health care professionals for the challenges related to nutrigenomic counselling.