What is personalised nutrition?

Internet and mobile phone technology has become integral to our daily activities and health and eating behaviour is no exception with recent technical advances having fuelled a drive towards direct-to-consumer (D-T-C) personalised nutrition. Personalised nutrition is an innovative concept that seeks to identify individual nutritional needs based on health status, genotype⁽ Reference Ronteltap and van Trijp ^{1 )} and/or phenotype⁽ Reference Boland ^{2 )} and then to provide healthy eating advice that is tailored to suit the individual (Food4me.org). Meanwhile, there is a growing body of evidence for the effectiveness of tailored feedback in bringing about healthy behaviour change⁽ Reference Gordon, Griffin and Wawak ^{3 –} Reference de Bourdeaudhuij and Brug ^{6 )}. Surveys of D-T-C services have suggested that they are effective in producing healthy behaviour change in approximately one-third of users⁽ Reference Egglestone, Morris and O'Brien ^{7 –} Reference O'Daniel, Haga and Willard ^{10 )}. Awareness of D-T-C genetic tests is increasing among consumers⁽ Reference Finney Rutten, Gollust and Naveed ^{11 )}. Those with a stake-hold in the delivery of personalised nutrition see immense potential to transform preventative and therapeutic nutrition and in doing so, to benefit public health and reduce health costs⁽ Reference Lewis and Burton-Freeman ^{12 )}. Personalised nutrition not only has potential for the tailoring of diet to individual health needs, but also to that of groups of people among the general public⁽ Reference Gibney ^{13 )}. For personalised nutrition intervention to have any real and enduring impact upon public health, however, we need to understand and take into account the public vision for such services⁽ Reference Onwezen, Reinders and van der Lans ^{14 )}. Early D-T-C personalised nutrition initiatives have, on the whole, not been commercially successful. Despite the recent rapid advance in interactive health technology⁽ Reference Lewis and Burton-Freeman ^{12 )} and the potential for societal benefit, there is a dearth of research in the area of personalised nutrition and nutrigenomics from the perspective of the general public⁽ Reference Su and Lu ^{15 ,} Reference de Vrieze, Bouwman and Komduur ^{16 )}. Much of what research exists has focused on genetic testing albeit in various contexts, while fewer studies have considered personalised nutrition in particular.

What do the public think about nutrigenomics?

The future success of personalised nutrition in practice will depend upon the public being ready and able to take up aspects of the technology that are essential to service delivery. Personalised medicine and personalised nutrition share certain technologies. Genetic profiling is common to personalised medicine and nutrition and is likely to be important (along with phenotype, etc.) in informing personalised nutrition initiatives in the future. Understanding attitudes towards genetic testing, therefore, is relevant to understanding public response to nutrigenomics which represents the more ‘medicalised’ level of personalised nutrition provision.

Qualitative enquiry into societal views on genetic testing undertaken in the USA⁽ Reference Glenn, Chawla and Bastani ^{17 –} Reference Doukas, Fetters and Coyne ^{23 )}, Australia⁽ Reference Keogh, McClaren and Maskiell ^{24 )}, Switzerland⁽ Reference Vayena, Gourna and Streuli ^{25 )}, the Netherlands⁽ Reference Wijdenes-Pijl, Dondorp and Timmermans ^{26 )} and the UK⁽ Reference Skirton ^{27 )}, has indicated that people are aware of the potential benefits and hold generally positive attitudes towards genetic testing. Potential drivers of the uptake of genetic testing include own health⁽ Reference Glenn, Chawla and Bastani ^{17 ,} Reference Streicher, Sanderson and Jabs ^{18 ,} Reference Keogh, McClaren and Maskiell ^{24 ,} Reference Hardie ^{28 ,} Reference McGowan, Fishman and Lambrix ^{29 )}, the health of other family members and descendants⁽ Reference Glenn, Chawla and Bastani ^{17 –} Reference Goldman, Kingdon and Wasser ^{19 ,} Reference Keogh, McClaren and Maskiell ^{24 )}, for research purposes⁽ Reference Glenn, Chawla and Bastani ^{17 ,} Reference Keogh, McClaren and Maskiell ^{24 ,} Reference Su, Howard and Borry ^{30 )} and curiosity⁽ Reference O'Daniel, Haga and Willard ^{10 ,} Reference Streicher, Sanderson and Jabs ^{18 ,} Reference Keogh, McClaren and Maskiell ^{24 ,} Reference Vayena, Gourna and Streuli ^{25 ,} Reference Hardie ^{28 ,} Reference Su, Howard and Borry ^{30 ,} Reference Basson, Futter and Greenberg ^{31 )}. All these studies, however, also catalogued concerns surrounding the enabling technology. Online privacy and the potential for information to be used by companies for commercial gain or to fall into the hands of insurers, employers or government agencies are among issues that have been consistently raised⁽ Reference Glenn, Chawla and Bastani ^{17 –} Reference Skirton ^{27 ,} Reference Wilde, Meiser and Mitchell ^{32 ,} Reference Nyrhinen, Leino-Kilpi and Hietala ^{33 )}. Aspects of the service delivery system itself may also need to be personalised. Whereas some studies of factors determining uptake of genetic testing⁽ Reference Doukas, Fetters and Coyne ^{23 ,} Reference Townsend, Adam and Birch ^{34 )}, have suggested that consumers liked the notion of autonomy and being in control⁽ Reference Nyrhinen, Leino-Kilpi and Hietala ^{33 )}, other works have implied that some consumers would prefer the input of a health professional⁽ Reference Wilde, Meiser and Mitchell ^{32 ,} Reference Rew, Mackert and Bonevac ^{35 ,} Reference Frazier, Calvin and Mudd ^{36 )}. In view of the differing perspectives, the mode of service delivery may need to be personalised.

Survey studies conducted in the USA⁽ Reference Haga, Barry and Mills ^{8 ,} Reference Kerath, Klein and Kern ^{37 –} Reference Durfy, Bowen and McTiernan ^{47 )}, Canada⁽ Reference Etchegary, Cappelli and Potter ^{48 )}, Russia⁽ Reference Makeeva, Markova and Roses ^{49 ,} Reference Makeeva, Markova and Puzyrev ^{50 )}, Finland⁽ Reference Toiviainen, Jallinoja and Aro ^{51 ,} Reference Aro, Hakonen and Hietala ^{52 )}, Sweden⁽ Reference Hoeyer, Olofsson and Mjörndal ^{53 )}, the Netherlands⁽ Reference Morren, Rijken and Baanders ^{54 )}, Australia⁽ Reference Wilde, Meiser and Mitchell ^{55 )}, Canada⁽ Reference Ries, Hyde-Lay and Caulfield ^{56 )} and the UK⁽ Reference Sanderson, Wardle and Jarvis ^{57 )} have indicated largely positive attitudes towards genetic testing. The public also appear positive about donating genetic material to biobanks⁽ Reference Goldman, Kingdon and Wasser ^{19 ,} Reference Brothers, Morrison and Clayton ^{58 ,} Reference Treweek, Doney and Leiman ^{59 )} and willing to supply genetic material for research purposes⁽ Reference Pulley, Brace and Bernard ^{60 )}. Reasons suggested by the public for taking up genetic testing not only include improving one's own health⁽ Reference Gollust, Gordon and Zayac ^{61 –} Reference Cappelli, Surh and Humphreys ^{64 )}, but also of other family members and descendants⁽ Reference Akinleye, Roberts and Royal ^{62 –} Reference Bosompra, Flynn and Ashikaga ^{66 )} . Unsurprisingly, therefore, those with a family history of inherited conditions have been found to have more favourable attitudes towards genetic testing⁽ Reference Catz, Green and Tobin ^{21 ,} Reference Wilde, Meiser and Mitchell ^{55 ,} Reference Kettis-Lindblad, Ring and Viberth ^{67 )} and may be willing to pay more⁽ Reference Ries, Hyde-Lay and Caulfield ^{56 )}. A sizeable proportion would avail of genetic testing for no reason other than curiosity⁽ Reference Hull, Sharp and Botkin ^{42 ,} Reference Makeeva, Markova and Roses ^{49 ,} Reference Makeeva, Markova and Puzyrev ^{50 ,} Reference Gollust, Gordon and Zayac ^{61 ,} Reference Akinleye, Roberts and Royal ^{62 ,} Reference Ormond, Hudgins and Ladd ^{68 )}. Others, on the other hand, may not want to know test results unless treatment was available⁽ Reference Hoeyer, Olofsson and Mjörndal ^{53 ,} Reference Morren, Rijken and Baanders ^{54 )}.

Despite generally positive attitudes towards genetic testing, and in keeping with existing qualitative studies into genetic testing (see previous paragraph), quantitative research, mainly surveys conducted over the last couple of decades conducted in the USA⁽ Reference Haga, Barry and Mills ^{8 ,} Reference Kerath, Klein and Kern ^{37 ,} Reference Ormond, Hudgins and Ladd ^{68 –} Reference Neumann, Hammitt and Mueller ^{71 )}, Canada⁽ Reference Etchegary, Cappelli and Potter ^{48 ,} Reference Ries, Hyde-Lay and Caulfield ^{56 )}, Australia⁽ Reference Taylor ^{72 )}, Europe⁽ Reference Gaskell, Allum and Stares ^{73 )}, the UK⁽ Reference Treweek, Doney and Leiman ^{59 )}, Finland⁽ Reference Jallinoja, Hakonen and Aro ^{74 ,} Reference Hietala, Hakonen and Aro ^{75 )} and the Netherlands⁽ Reference Henneman, Vermeulen and van El ^{76 )} also indicate considerable concern among the public about internet privacy, data security, data use and data destiny⁽ Reference McGuire, Diaz and Wang ^{41 ,} Reference Peters, Rose and Armstrong ^{43 ,} Reference Singer, Antonucci and Hoewyk ^{44 ,} Reference Toiviainen, Jallinoja and Aro ^{51 –} Reference Ries, Hyde-Lay and Caulfield ^{56 )}. Previous surveys into public attitudes towards genomics⁽ Reference Aro, Hakonen and Hietala ^{52 ,} Reference Hoeyer, Olofsson and Mjörndal ^{53 ,} Reference Wilde, Meiser and Mitchell ^{55 ,} Reference Kettis-Lindblad, Ring and Viberth ^{67 )}, however, have failed to recruit samples that have been representative of the general population, making it difficult to draw firm conclusions as to the response of various societal groups to this emerging technology. Attitudes to genetic testing, however, appear to vary by gender, age and educational level. Males⁽ Reference Haga, Barry and Mills ^{8 ,} Reference Aro, Hakonen and Hietala ^{52 ,} Reference Sanderson, Wardle and Jarvis ^{57 ,} Reference Cherkas, Harris and Levinson ^{63 )} and older individuals⁽ Reference Finney Rutten, Gollust and Naveed ^{11 ,} Reference Kerath, Klein and Kern ^{37 ,} Reference Aro, Hakonen and Hietala ^{52 ,} Reference Sanderson, Wardle and Jarvis ^{57 )} appear most favourable towards the notion of genetic testing. Analyses of the impact of education level upon attitudes towards genetic testing have produced mixed results⁽ Reference Finney Rutten, Gollust and Naveed ^{11 ,} Reference Catz, Green and Tobin ^{21 ,} Reference Hensley Alford, McBride and Reid ^{40 ,} Reference Donovan and Tucker ^{46 ,} Reference Jonassaint, Santos and Glover ^{77 –} Reference Hughes, Gomez-Caminero and Benkendorf ^{79 )}. Those educated to a higher educational level⁽ Reference Catz, Green and Tobin ^{21 ,} Reference Goddard, Moore and Ottman ^{78 )} and those in minority ethnic groups⁽ Reference Peters, Rose and Armstrong ^{43 ,} Reference Singer, Antonucci and Hoewyk ^{44 )} appear particularly concerned over data protection, use and destiny.

What does the public think about personalised nutrition?

Whereas personalised medicine relates genotypic information to propensity for disease, personalised nutrition relates genotypic information to optimal diet and health⁽ Reference Gibney and Walsh ^{80 )}. Personalised nutrition also differs from nutrigenomics in taking a broader view of health and dietary health promotion and considering not only genotype, but also phenotype and lifestyle. This could render personalised nutrition less ethically sensitive and more amenable to public health promotion. However, consumer response to nutrigenomics and personalised nutrition remains an under researched area. Only a handful of qualitative (Morin⁽ Reference Morin ^{81 )}) and survey⁽ Reference Stewart-Knox, Bunting and Gilpin ^{82 ,} Reference Roosen, Bruhn and Mecking ^{83 )} studies have considered the public perspective of nutrigenomics, all of which have indicated that between one-third and a one-half of those surveyed would be willing to avail such services and to follow a tailored diet. Having a health problem was also associated with being positive about receiving genetic-profiling information for the purpose of personalising their diet⁽ Reference Stewart-Knox, Bunting and Gilpin ^{82 ,} Reference Roosen, Bruhn and Mecking ^{83 )}. Research conducted in the Netherlands has indicated that consumers may be more amenable towards web-based personalised nutrition if they were in control of the use of the results⁽ Reference Ronteltap, van Trijp and Renes ^{84 )}. In keeping with this notion, other studies have implied that doubts about data security, data use and destiny would deter use of such services⁽ Reference Stewart-Knox, Bunting and Gilpin ^{82 ,} Reference Roosen, Bruhn and Mecking ^{83 )}.

What does the future hold for personalised nutrition?

Previous research findings provide some clues as to why despite evidence that tailored interventions are effective in bringing about healthy behaviour change, early attempts to deliver personalised nutrition services on a commercial scale have failed. Expectancy value theories allow us to consider the implications of these findings for behaviour change. Protection motivation theory⁽ Reference Maddux and Rogers ^{87 –} Reference Floyd, Prentice-Dunn and Rogers ^{89 )} holds that the likelihood of a behaviour occurring, for example, taking up personalised nutrition, will depend upon the perceived size, severity and likelihood of any associated risk and perceived ability to reduce the risk. This implies a need for further consumer research to establish the perceived size, severity and likelihood of risk associated with online D-T-C personalised nutrition as well as perceived ability to reduce the risk and interaction with perceived benefit.

The overarching message from the research into the public response to genetic testing, nutrigenomics and personalised nutrition is that for D-T-C personalised nutrition to be taken up on a societal scale, people will need assurances that all online interactions would be private and that the provider will have ability to effectively handle and protect information collected in the endeavour to design personalised diets. In the wake of accidents resulting in public data falling into the ‘wrong’ hands and recent revelations about how data generated through social media and other personal internet activities is used for marketing purposes and commercial gain, perceived weaknesses inherent in such technology are likely to limit the future development, consumer uptake and growth of such services.

Potential consumers, although positive about the concept of personalised nutrition, are telling us that in order for them to take up such services the information collected will require regulation⁽ Reference Ahlgren, Nordgren and Perrudin ^{90 )}. Control of the handling and use of health-related data will only be effective if the technology is in place to enable compliance with regulation⁽ Reference Bollinger, Green and Kaufman ^{91 )}. Interdisciplinary research and innovation is needed urgently to render the delivery of health systems such as personalised nutrition secure and enable this potentially important public health innovation. Delivering personalised nutrition to the public will require working closely with information technologists in getting the delivery system perfected. Technological innovation has driven the concept of D-T-C health systems. The future of personalised nutrition would also appear to lie in the hands of information technologists. Meanwhile, promotion of personalised nutrition to the general public would do well to emphasise the (personal) benefits of personalised nutrition.