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Our group built a genetic risk score (GRS) of the plasma triglyceride (TG) response to an omega-3 (n-3) fatty acid (FA) supplementation in Caucasian Canadians that explained 21.53% of the TG variance. The objective was to refine the GRS by fine mapping and to test its association with the TG response in young Mexican adults. A total of 191 participants underwent a 6-week n-3 FA supplementation providing 2.7g/day of docosahexaenoic and eicosapentaenoic acids. Using quantitative polymerase chain reaction (PCR), 103 single-nucleotide polymorphisms (SNPs) were genotyped. A stepwise regression adjusted for age, sex, and body mass index (BMI) was used to select the strongest SNPs to include in the genetic risk model. A GRS was calculated from the sum of at-risk alleles. The contribution of the GRS to the TG response was assessed by ANCOVA with age, sex, and BMI included in the model. Several differences in allele frequency were observed between Canadians and Mexicans. Five lead SNPs were included in the genetic risk model, in which the GRS accounted for 11.01% of the variance of the TG response (p < 0.0001). These findings highlight the important contribution of genetic factors to the heterogeneity of the TG response to an n-3 FA supplementation among Mexicans.

A recent genome-wide association study (GWAS) by our group identified 13 loci associated with the plasma triglyceride (TG) response to omega-3 (n-3) fatty acid (FA) supplementation. This study aimed to test whether single-nucleotide polymorphisms (SNPs) within the IQCJ, NXPH1, PHF17 and MYB genes are associated with the plasma TG response to an n-3 FA supplementation. Methods: A total of 208 subjects followed a 6-week n-3 FA supplementation of 5 g/day of fish oil (1.9-2.2 g of eicosapentaenoic acid and 1.1 g of docosahexaenoic acid). Measurements of plasma lipids were made before and after the supplementation. Sixty-seven tagged SNPs were selected to increase the density of markers near GWAS hits. Results: In a repeated model, independent effects of the genotype and the gene-supplementation interaction were associated with plasma TG. Genotype effects were observed with two SNPs of NXPH1, and gene-diet interactions were observed with ten SNPs of IQCJ, four SNPs of NXPH1 and three SNPs of MYB. Positive and negative responders showed different genotype frequencies with nine SNPs of IQCJ, two SNPs of NXPH1 and two SNPs of MYB. Conclusion: Fine mapping in GWAS-associated loci allowed the identification of SNPs partly explaining the large interindividual variability observed in plasma TG levels in response to an n-3 FA supplementation.

Background : We previously built a genetic risk score (GRS) highly predictive of the plasma triglyceride (TG) response to an omega-3 fatty acid (n-3 FA) supplementation from marine sources. The objective of the present study was to test the potential of this GRS to predict the plasma TG responsiveness to supplementation with either eicosapentaenoic (EPA) or docosahexaenoic (DHA) acids in the Comparing EPA to DHA (ComparED) Study. Methods : The ComparED Study is a double-blind, controlled, crossover trial, with participants randomized to three supplemented phases of 10 weeks each: (1) 2.7 g/day of DHA, (2) 2.7 g/day of EPA, and (3) 3 g/day of corn oil (control), separated by 9-week washouts. The 31 SNPs used to build the previous GRS were genotyped in 122 participants of the ComparED Study using TaqMan technology. The GRS for each participant was computed by summing the number of rare alleles. Ordinal and binary logistic models, adjusted for age, sex, and body mass index, were used to calculate the ability of the GRS to predict TG responsiveness. Results : The GRS predicted TG responsiveness to EPA supplementation (p = 0.006), and a trend was observed for DHA supplementation (p = 0.08). The exclusion of participants with neutral TG responsiveness clarified the association patterns and the predictive capability of the GRS (EPA, p = 0.0003, DHA p = 0.01). Conclusion : Results of the present study suggest that the constructed GRS is a good predictor of the plasma TG response to supplementation with either DHA or EPA.

Objective: The purpose of this study was to draw a global portrait of the current knowledge and interest regarding nutrigenetics in a population of French Canadians from the province of Quebec (Canada). Methods: A total of 2238 residents from the province of Quebec, Canada, were recruited via social networks and from the Laval University employees/students lists to participate to a 37-question online survey on nutrigenetics. Results: Most participants were not familiar with the term “nutrigenetics” (82.7%). Participants with good genetic literacy (26.8%) were less interested in nutrigenetic testing (p<0.0001). The vast majority of participants (90.7%) reported to be willing to follow a personalized diet based on nutrigenetic testing, especially if they came to know themselves as carriers of a polymorphism increasing the risk of certain diseases. Participants had higher interest in testing related to metabolic response to macronutrients (types of sugars, fats and proteins) than to micronutrients or other nutrients related to food intolerance. Conclusions: The attitude of French Canadians about nutrigenetics are very consistent with results from other survey published in the literature. Although few individuals are familiar with nutrigenetics, public’s attitude towards nutrigenetics is globally favourable.

Background: Using a genome-wide association study (GWAS) approach, our group 3 previously computed a genetic risk score (GRS) from single nucleotide polymorphisms 4 (SNPs) of ten loci which affect the plasma triglyceride (TG) response to an omega-3 (n-3) 5 fatty acid (FA) supplementation. 6 Objective: The objective was to compute a novel and more refined GRS using fine 7 mapping to include a large number of genetic variants. 8 Design: A total of 208 participants of the Fatty Acid Sensor (FAS) study received 5g of 9 fish oil per day, containing 1.9–2.2g of eicosapentanoic acid and 1.1g of docosahexanoic 10 acid, for six weeks. Plasma TG levels were measured before and after supplementation. 11 Dense genotyping and genotype imputation were employed to refine mapping around 12 GWAS hits. A GRS was computed by summing the number of at-risk alleles of tagging 13 SNPs. Analyses were replicated in samples of the FINGEN study. 14 Results: A total of 31 tagging SNPs associated with the TG response were used for GRS 15 calculation in the FAS study. In a general linear model adjusted for age, sex and body 16 mass index, the GRS explained 49.73% of TG response variance (p < 0.0001). Non17 responders to the n-3 FA supplementation had a higher GRS than responders. In the 18 FINGEN replication study, the GRS explained 3.67% of TG response variance (p = 19 0.0006). 20 Conclusion: Fine mapping proved to be effective to refine the previous GRS. Carrying 21 increasing numbers of at-risk alleles of 31 SNPs confers a higher risk of being non22 responsive to n-3 FA. The genetic profile therefore appears to be an important determinant of the plasma TG response to an n-3 FA supplementation and could be used to target 24 those most likely to gain clinical benefit.

The objective was to test whether FFAR4 single nucleotide polymorphisms (SNPs) are associated with glycemic control-related traits in humans following fish oil supplementation. A total of 210 participants were given 3 g/day of omega-3 (n-3) fatty acids (FA) (1.9–2.2 g of eicosapentaenoic acid (EPA) and 1.1 g of docosahexaenoic acid (DHA)) during six weeks. Biochemical parameters were taken before and after the supplementation. Using the HapMap database and the tagger procedure in Haploview, 12 tagging SNPs in FFAR4 were selected and then genotyped using TaqMan technology. Transcript expression levels were measured for 30 participants in peripheral mononuclear blood cells. DNA methylation levels were measured for 35 participants in leukocytes. In silico analyses were also performed. Four gene–diet interactions on fasting insulin levels and homeostatic model assessment of insulin resistance (HOMA-IR) index values were found. rs17108973 explained a significant proportion of the variance of insulin levels (3.0%) and HOMA-IR (2.03%) index values. Splice site prediction was different depending on the allele for rs11187527. rs17108973 and rs17484310 had different affinity for transcription factors depending on the allele. n-3 FAs effectively improve insulin-related traits for major allele homozygotes of four FFAR4 SNPs as opposed to carriers of the minor alleles.

Background : We previously built a genetic risk score (GRS) highly predictive of the plasma triglyceride (TG) response to an omega-3 fatty acid (n-3 FA) supplementation from marine sources. The objective of the present study was to test the potential of this GRS to predict the plasma TG responsiveness to supplementation with either eicosapentaenoic (EPA) or docosahexaenoic (DHA) acids in the Comparing EPA to DHA (ComparED) Study. Methods : The ComparED Study is a double-blind, controlled, crossover trial, with participants randomized to three supplemented phases of 10 weeks each: (1) 2.7 g/day of DHA, (2) 2.7 g/day of EPA, and (3) 3 g/day of corn oil (control), separated by 9-week washouts. The 31 SNPs used to build the previous GRS were genotyped in 122 participants of the ComparED Study using TaqMan technology. The GRS for each participant was computed by summing the number of rare alleles. Ordinal and binary logistic models, adjusted for age, sex, and body mass index, were used to calculate the ability of the GRS to predict TG responsiveness. Results : The GRS predicted TG responsiveness to EPA supplementation (p = 0.006), and a trend was observed for DHA supplementation (p = 0.08). The exclusion of participants with neutral TG responsiveness clarified the association patterns and the predictive capability of the GRS (EPA, p = 0.0003, DHA p = 0.01). Conclusion : Results of the present study suggest that the constructed GRS is a good predictor of the plasma TG response to supplementation with either DHA or EPA.

Background/aims: This study aimed to evaluate attitudes, perceptions and concerns about nutrigenetic testing for personalized nutrition in the general population of the province of Quebec, in Canada. Methods: A total of 1425 individuals from the province of Quebec fully completed a 37 question online survey on nutrigenetics and were included in analyses. Chi-square tests were used to test for associations between categorical variables. Results: The majority of participants (93.3%) considered dietitians as the best professionals to give personalized dietary advice based on nutrigenetic testing. The main reported advantage for nutrigenetic testing was “health” (23.5%), followed by “disease prevention” (22.2%). Among disadvantages, “no disadvantage” (24.4%), followed by “diet restriction” (12.9%) were mostly reported. The two major concerns raised were the accessibility to genetic testing by telemarketing companies and spammers (51.8%), and solicitation by companies using the personal genetic data to sell products (48.6%). Conclusions: French Canadians generally have a positive attitude towards nutrigenetics and find many benefits to its use. They rose up possible confidentiality issues associated with the management or property of genetic test results. However education about confidentiality issues is still considerably needed. These findings overall suggest that the population is interested by a more extensive use of nutrigenetics in health management.

Objective: The purpose of this study was to draw a global portrait of the current knowledge and interest regarding nutrigenetics in a population of French Canadians from the province of Quebec (Canada). Methods: A total of 2238 residents from the province of Quebec, Canada, were recruited via social networks and from the Laval University employees/students lists to participate to a 37-question online survey on nutrigenetics. Results: Most participants were not familiar with the term “nutrigenetics” (82.7%). Participants with good genetic literacy (26.8%) were less interested in nutrigenetic testing (p<0.0001). The vast majority of participants (90.7%) reported to be willing to follow a personalized diet based on nutrigenetic testing, especially if they came to know themselves as carriers of a polymorphism increasing the risk of certain diseases. Participants had higher interest in testing related to metabolic response to macronutrients (types of sugars, fats and proteins) than to micronutrients or other nutrients related to food intolerance. Conclusions: The attitude of French Canadians about nutrigenetics are very consistent with results from other survey published in the literature. Although few individuals are familiar with nutrigenetics, public’s attitude towards nutrigenetics is globally favourable.

Our group built a genetic risk score (GRS) of the plasma triglyceride (TG) response to an omega-3 (n-3) fatty acid (FA) supplementation in Caucasian Canadians that explained 21.53% of the TG variance. The objective was to refine the GRS by fine mapping and to test its association with the TG response in young Mexican adults. A total of 191 participants underwent a 6-week n-3 FA supplementation providing 2.7g/day of docosahexaenoic and eicosapentaenoic acids. Using quantitative polymerase chain reaction (PCR), 103 single-nucleotide polymorphisms (SNPs) were genotyped. A stepwise regression adjusted for age, sex, and body mass index (BMI) was used to select the strongest SNPs to include in the genetic risk model. A GRS was calculated from the sum of at-risk alleles. The contribution of the GRS to the TG response was assessed by ANCOVA with age, sex, and BMI included in the model. Several differences in allele frequency were observed between Canadians and Mexicans. Five lead SNPs were included in the genetic risk model, in which the GRS accounted for 11.01% of the variance of the TG response (p < 0.0001). These findings highlight the important contribution of genetic factors to the heterogeneity of the TG response to an n-3 FA supplementation among Mexicans.

Background: Using a genome-wide association study (GWAS) approach, our group 3 previously computed a genetic risk score (GRS) from single nucleotide polymorphisms 4 (SNPs) of ten loci which affect the plasma triglyceride (TG) response to an omega-3 (n-3) 5 fatty acid (FA) supplementation. 6 Objective: The objective was to compute a novel and more refined GRS using fine 7 mapping to include a large number of genetic variants. 8 Design: A total of 208 participants of the Fatty Acid Sensor (FAS) study received 5g of 9 fish oil per day, containing 1.9–2.2g of eicosapentanoic acid and 1.1g of docosahexanoic 10 acid, for six weeks. Plasma TG levels were measured before and after supplementation. 11 Dense genotyping and genotype imputation were employed to refine mapping around 12 GWAS hits. A GRS was computed by summing the number of at-risk alleles of tagging 13 SNPs. Analyses were replicated in samples of the FINGEN study. 14 Results: A total of 31 tagging SNPs associated with the TG response were used for GRS 15 calculation in the FAS study. In a general linear model adjusted for age, sex and body 16 mass index, the GRS explained 49.73% of TG response variance (p < 0.0001). Non17 responders to the n-3 FA supplementation had a higher GRS than responders. In the 18 FINGEN replication study, the GRS explained 3.67% of TG response variance (p = 19 0.0006). 20 Conclusion: Fine mapping proved to be effective to refine the previous GRS. Carrying 21 increasing numbers of at-risk alleles of 31 SNPs confers a higher risk of being non22 responsive to n-3 FA. The genetic profile therefore appears to be an important determinant of the plasma TG response to an n-3 FA supplementation and could be used to target 24 those most likely to gain clinical benefit.

A genome-wide association study (GWAS) by our group identified loci associated with the plasma triglyceride (TG) response to ω-3 fatty acid (FA) supplementation in IQCJ, NXPH1, PHF17 and MYB. Our aim is to investigate potential mechanisms underlying the associations between single nucleotide polymorphisms (SNPs) in the four genes and TG levels following ω-3 FA supplementation. 208 subjects received 3 g/day of ω-3 FA (1.9–2.2 g of EPA and 1.1 g of docosahexaenoic acid (DHA)) for six weeks. Plasma TG were measured before and after the intervention. 67 SNPs were selected to increase the density of markers near GWAS hits. Genome-wide expression and methylation analyses were conducted on respectively 30 and 35 participants’ blood sample together with in silico analyses. Two SNPs of IQCJ showed different affinities to splice sites depending on alleles. Expression levels were influenced by genotype for one SNP in NXPH1 and one in MYB. Associations between 12 tagged SNPs of IQCJ, 26 of NXPH1, seven of PHF17 and four of MYB and gene-specific CpG site methylation levels were found. The response of plasma TG to ω-3 FA supplementation may be modulated by the effect of DNA methylation on expression levels of genes revealed by GWAS.

The objective was to test whether FFAR4 single nucleotide polymorphisms (SNPs) are associated with glycemic control-related traits in humans following fish oil supplementation. A total of 210 participants were given 3 g/day of omega-3 (n-3) fatty acids (FA) (1.9–2.2 g of eicosapentaenoic acid (EPA) and 1.1 g of docosahexaenoic acid (DHA)) during six weeks. Biochemical parameters were taken before and after the supplementation. Using the HapMap database and the tagger procedure in Haploview, 12 tagging SNPs in FFAR4 were selected and then genotyped using TaqMan technology. Transcript expression levels were measured for 30 participants in peripheral mononuclear blood cells. DNA methylation levels were measured for 35 participants in leukocytes. In silico analyses were also performed. Four gene–diet interactions on fasting insulin levels and homeostatic model assessment of insulin resistance (HOMA-IR) index values were found. rs17108973 explained a significant proportion of the variance of insulin levels (3.0%) and HOMA-IR (2.03%) index values. Splice site prediction was different depending on the allele for rs11187527. rs17108973 and rs17484310 had different affinity for transcription factors depending on the allele. n-3 FAs effectively improve insulin-related traits for major allele homozygotes of four FFAR4 SNPs as opposed to carriers of the minor alleles.

A recent genome-wide association study (GWAS) by our group identified 13 loci associated with the plasma triglyceride (TG) response to omega-3 (n-3) fatty acid (FA) supplementation. This study aimed to test whether single-nucleotide polymorphisms (SNPs) within the IQCJ, NXPH1, PHF17 and MYB genes are associated with the plasma TG response to an n-3 FA supplementation. Methods: A total of 208 subjects followed a 6-week n-3 FA supplementation of 5 g/day of fish oil (1.9-2.2 g of eicosapentaenoic acid and 1.1 g of docosahexaenoic acid). Measurements of plasma lipids were made before and after the supplementation. Sixty-seven tagged SNPs were selected to increase the density of markers near GWAS hits. Results: In a repeated model, independent effects of the genotype and the gene-supplementation interaction were associated with plasma TG. Genotype effects were observed with two SNPs of NXPH1, and gene-diet interactions were observed with ten SNPs of IQCJ, four SNPs of NXPH1 and three SNPs of MYB. Positive and negative responders showed different genotype frequencies with nine SNPs of IQCJ, two SNPs of NXPH1 and two SNPs of MYB. Conclusion: Fine mapping in GWAS-associated loci allowed the identification of SNPs partly explaining the large interindividual variability observed in plasma TG levels in response to an n-3 FA supplementation.