Background/Aims: Direct-to-consumer (DTC) genetic tests have facilitated easy access to personal genetic information related to health and nutrition; however, consumer perceptions of the nutritional information provided by these tests have not been evaluated. The objectives of this study were to assess individual perceptions of personalized nutrition and genetic testing and to determine whether a personalized nutrition intervention modifies perceptions. Methods: A double-blind, parallel-group, randomized controlled trial was conducted among healthy men and women aged 20-35 years (n = 138). Participants in the intervention group (n = 92) were given a report of DNA-based dietary advice and those in the control group (n = 46) were given a general dietary advice report. A survey was completed at baseline and 3 and 12 months after distributing the reports to assess perceptions between the two groups. Results: No significant differences in perceptions of personalized nutrition and genetic testing were observed between the intervention and control group, so responses of both groups were combined. As compared to baseline, participant responses increased significantly toward the positive end of a Likert scale at 3 months for the statement ‘I am interested in the relationship between diet and genetics' (mean change ± SD: 0.28 ± 0.99, p = 0.0002). The majority of participants indicated that a university research lab (47%) or health care professional (41%) were the best sources for obtaining accurate personal genetic information, while a DTC genetic testing company received the fewest selections (12%). Most participants (56%) considered dietitians to be the best source of personalized nutrition followed by medical doctors (27%), naturopaths (8%) and nurses (6%). Conclusions: These results suggest that perceptions of personalized nutrition changed over the course of the intervention. Individuals view a research lab or health care professional as better providers of genetic information than a DTC genetic testing company, and registered dietitians are considered to be the best providers of personalized nutrition advice.

Sterling R: The on-line promotion and sale of nutrigenomic services. Genet Med 2008;10:784-796.
Coghlan A: 23andMe ordered to stop selling $99 genetic test. New Scientist, 2013. (accessed April 23, 2014).
O'Connor L: 23andMe faces $5 million lawsuit days after being banned by FDA. The Huffington Post, December 4, 2013. (accessed April 23, 2014).
Human Genetics Commission: A common framework of principles for direct-to-consumer genetic testing services. 2010. (accessed April 23, 2014).
Wagner JK: Understanding FDA regulation of DTC genetic tests within the context of administrative law. Am J Hum Genet 2010;87:451-456.
Borry P, van Hellemondt RE, Sprumont D, Jales CF, Rial-Sebbag E, Spranger TM, Curren L, Kaye J, Nys H, Howard H: Legislation on direct-to-consumer genetic testing in seven European countries. Eur J Hum Genet 2012;20:715-721.
Cherkas LF, Harris JM, Levinson E, Spector TD, Prainsack B: A survey of UK public interest in internet-based personal genome testing. PLoS One 2010;5:e13473.
Goddard KA, Duquette D, Zlot A, Johnson J, Annis-Emeott A, Lee PW, Bland MP, Edwards KL, Oehlke K, Giles RT, Rafferty A, Cook ML, Khoury MJ: Public awareness and use of direct-to-consumer genetic tests: results from 3 state population-based surveys, 2006. Am J Public Health 2009;99:442-445.
Kolor K, Duquette D, Zlot A, Foland J, Anderson B, Giles R, Wrathall J, Khoury MJ: Public awareness and use of direct-to-consumer personal genomic tests from four state population-based surveys, and implications for clinical and public health practice. Genet Med 2012;14:860-867.
Stewart-Knox BJ, Bunting BP, Gilpin S, Parr HJ, Pinhao S, Strain JJ, de Almeida MD, Gibney M: Attitudes toward genetic testing and personalised nutrition in a representative sample of European consumers. Br J Nutr 2009;101:982-989.
Ronteltap A, van Trijp JC, Renes RJ: Consumer acceptance of nutrigenomics-based personalised nutrition. Br J Nutr 2009;101:132-144.
Roosen J, Bruhn M, Mecking RA, Drescher LS: Consumer demand for personalized nutrition and functional food. Int J Vitam Nutr Res 2008;78:269-274.
Goddard KA, Moore C, Ottman D, Szegda KL, Bradley L, Khoury MJ: Awareness and use of direct-to-consumer nutrigenomic tests, United States, 2006. Genet Med 2007;9:510-517.
Stenne R, Hurlimann T, Godard B: Benefits associated with nutrigenomics research and their reporting in the scientific literature: researchers' perspectives. Account Res 2013;20:167-183.
Nielsen DE, El-Sohemy A: A randomized trial of genetic information for personalized nutrition. Genes Nutr 2012;7:559-566.
Nawrot P, Jordan S, Eastwood J, Rotstein J, Hugenholtz A, Feeley M: Effects of caffeine on human health. Food Addit Contam 2003;20:1-30.
Otten JJ, Hellwig JP, Meyers LD (eds): Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. Washington, National Academies Press, 2006.
Nishida C, Uauy R, Kumanyika S, Shetty P: The joint WHO/FAO expert consultation on diet, nutrition and the prevention of chronic diseases: process, product and policy implications. Public Health Nutr 2004;7:245-250.
Cornelis MC, El-Sohemy A, Kabagambe EK, Campos H: Coffee, cyp1a2 genotype, and risk of myocardial infarction. JAMA 2006;295:1135-1141.
Palatini P, Ceolotto G, Ragazzo F, Dorigatti F, Saladini F, Papparella I, Mos L, Zanata G, Santonastaso M: CYP1A2 genotype modifies the association between coffee intake and the risk of hypertension. J Hypertens 2009;27:1594-1601.
Cahill LE, Fontaine-Bisson B, El-Sohemy A: Functional genetic variants of glutathione S-transferase protect against serum ascorbic acid deficiency. Am J Clin Nutr 2009;90:1411-1417.
Giner V, Poch E, Bragulat E, Oriola J, Gonzalez D, Coca A, De La Sierra A: Renin-angiotensin system genetic polymorphisms and salt sensitivity in essential hypertension. Hypertension 2000;35:512-517.
Poch E, Gonzalez D, Giner V, Bragulat E, Coca A, de La Sierra A: Molecular basis of salt sensitivity in human hypertension. Evaluation of renin-angiotensin-aldosterone system gene polymorphisms. Hypertension 2001;38:1204-1209.
Narum SR: Beyond Bonferroni. Less conservative analyses for conservation genetics. Conserv Genet 2006;7:783-787.
Rosenstock IM, Strecher VJ, Becker MH: Social learning theory and the health belief model. Health Educ Q 1988;15:175-183.
Maher B: Nature readers flirt with personal genomics. Nature 2011;478:19.
Kaufman DJ, Bollinger JM, Dvoskin RL, Scott JA: Risky business: risk perception and the use of medical services among customers of DTC personal genetic testing. J Genet Couns 2012;21:413-422.
Almeling R, Gadarian SK: Public opinion on policy issues in genetics and genomics. Genet Med 2014;16:491-494.
Morin K: Knowledge and attitudes of Canadian consumers and health care professionals regarding nutritional genomics. OMICS 2009;13:37-41.
Ferguson LR, Barnett MPG: Research in nutrigenomics and potential applications to practice. Nutr Diet 2012;69:198-202.
Weir M, Morin K, Ries N, Castle D: Canadian health care professionals' knowledge, attitudes and perceptions of nutritional genomics. Br J Nutr 2010;104:1112-1119.
Birmingham WC, Agarwal N, Kohlmann W, Aspinwall LG, Wang M, Bishoff J, Dechet C, Kinney AY: Patient and provider attitudes toward genomic testing for prostate cancer susceptibility: a mixed method study. BMC Health Serv Res 2013;13:279.
Cormier H, Tremblay BL, Paradis AM, Garneau V, Desroches S, Robitaille J, Vohl MC: Nutrigenomics - perspectives from registered dietitians: a report from the Quebec-wide e-consultation on nutrigenomics among registered dietitians. J Hum Nutr Diet 2014;27:391-400.
Harris A, Kelly SE, Wyatt S: Counseling customers: emerging roles for genetic counselors in the direct-to-consumer genetic testing market. J Genet Couns 2013;22:277-288.
Salari K, Karczewski KJ, Hudgins L, Ormond KE: Evidence that personal genome testing enhances student learning in a course on genomics and personalized medicine. PLoS One 2013;8:e68853.
McBride CM, Bryan AD, Bray MS, Swan GE, Green ED: Health behavior change: can genomics improve behavioral adherence? Am J Public Health 2012;102:401-405.
Bloss CS, Schork NJ, Topol EJ: Effect of direct-to-consumer genomewide profiling to assess disease risk. N Engl J Med 2011;364:524-534.
Bloss CS, Wineinger NE, Darst BF, Schork NJ, Topol EJ: Impact of direct-to-consumer genomic testing at long term follow-up. J Med Genet 2013;50:393-400.
Hurlimann T, Menuz V, Graham J, Robitaille J, Vohl MC, Godard B: Risks of nutrigenomics and nutrigenetics? What the scientists say. Genes Nutr 2014;9:370.
Grant RW, O'Brien KE, Waxler JL, Vassy JL, Delahanty LM, Bissett LG, Green RC, Stember KG, Guiducci C, Park ER, Florez JC, Meigs JB: Personalized genetic risk counseling to motivate diabetes prevention: a randomized trial. Diabetes Care 2013;36:13-19.
Arkadianos I, Valdes AM, Marinos E, Florou A, Gill RD, Grimaldi KA: Improved weight management using genetic information to personalize a calorie controlled diet. Nutr J 2007;6:29.
Chao S, Roberts JS, Marteau TM, Silliman R, Cupples LA, Green RC: Health behavior changes after genetic risk assessment for Alzheimer disease: the reveal study. Alzheimer Dis Assoc Disord 2008;22:94-97.
Gollust SE, Gordon ES, Zayac C, Griffin G, Christman MF, Pyeritz RE, Wawak L, Bernhardt BA: Motivations and perceptions of early adopters of personalized genomics: perspectives from research participants. Public Health Genomics 2012;15:22-30.
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