Media Releases

Genetic testing for personalized nutrition leads to better outcomes

November 17, 2014

TORONTO, ON — Per­son­al­ized dietary advice based on a person’s genet­ic make­up improves eat­ing habits com­pared to cur­rent “one-size-fits-all” dietary rec­om­men­da­tions, says a Uni­ver­si­ty of Toron­to researcher.

The find­ings were pub­lished online Novem­ber 14 in the jour­nal PLOS ONE.‎

“We con­duct­ed the first ran­dom­ized, con­trolled tri­al to deter­mine the impact of dis­clos­ing DNA-based dietary advice on eat­ing habits,” said Ahmed El-Sohe­my, an asso­ciate pro­fes­sor in nutri­tion­al sci­ences and Cana­da Research Chair in Nutrige­nomics. “We found that peo­ple who receive DNA-based advice improve their diet to a greater extent than those who receive the stan­dard dietary advice.

“They’re also the ones who need to change it the most.”

Nutrige­nomics is a field of research that aims to under­stand why some peo­ple respond dif­fer­ent­ly than oth­ers to the same foods. Per­son­al­ized nutri­tion, a branch of per­son­al­ized med­i­cine, is an appli­ca­tion of nutrige­nomics that helps tai­lor dietary rec­om­men­da­tions to a person’s DNA.

The researchers col­lect­ed data on the intake of caf­feine, sodi­um, vit­a­min C and sug­ar from 138 healthy young adults. The sub­jects were then ran­dom­ized into two dif­fer­ent study groups – one was giv­en DNA-based dietary advice for each of the four dietary com­po­nents of inter­est, and the oth­er group was giv­en cur­rent stan­dard dietary advice for the same dietary com­po­nents with no genet­ic infor­ma­tion.

Changes in their dietary habits were assessed after three and 12 months. The researchers found that sub­jects who received DNA-based dietary advice start­ed to show improve­ments to their diets after three months and the changes became even more appar­ent after 12 months. Specif­i­cal­ly, those who were informed that they car­ried a ver­sion of a gene linked to salt intake and high blood pres­sure sig­nif­i­cant­ly reduced their sodi­um intake, in accor­dance with the rec­om­men­da­tion, com­pared to the group that was not giv­en genet­ic infor­ma­tion and received the stan­dard advice for sodi­um intake.

No effects were observed for the oth­er com­po­nents of the diet. How­ev­er, most sub­jects were already meet­ing the dietary rec­om­men­da­tions for the three oth­er com­po­nents at the start of the study, and the researchers believe this might explain why no sig­nif­i­cant changes were seen in these intakes.

“This study address­es some notable lim­i­ta­tions in pre­vi­ous stud­ies that attempt­ed to mea­sure the impact of dis­clos­ing genet­ic infor­ma­tion on lifestyle changes,” says El-Sohe­my. “Pre­vi­ous stud­ies focused on dis­ease risk pre­dic­tion rather than meta­bol­ic genes that affect spe­cif­ic com­po­nents of the diet. This is the first time that the impact of dietary advice based on diet-relat­ed genes with spe­cif­ic action­able advice has been test­ed.”

The sub­jects in the study received dietary advice reports that were devel­oped in col­lab­o­ra­tion with Nutrigenomix Inc., a U of T start-up com­pa­ny that devel­ops genet­ic test kits for per­son­al­ized nutri­tion only through qual­i­fied health­care pro­fes­sion­als.

- 30 -

For more infor­ma­tion, please con­tact:

Michael Kennedy
Media Rela­tions
Tel: 416–946-5025

Ahmed El-Sohe­my
Asso­ciate Pro­fes­sor
Depart­ment of Nutri­tion­al Sci­ences
Tel: 416–946-5776