Iwona Traczyk

Prof. Iwona Traczyk

orcid

Research Focus & Metrics

Academic Career Length

24Years (2003-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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12 August 2016 in International Journal of Epidemiology
Verified
Journal Article
Open access
PDF file
CCCarlos Celis-Morales
Carlos Celis-Morales
KLKatherine Livingstone
Katherine Livingstone
CMCyril F. M. Marsaux
Cyril F. M. Marsaux
AMAnna L. Macready
Anna L. Macready
RFRosalind Fallaize
Rosalind Fallaize
JMJohn Mathers
John Mathers
Background: Optimal nutritional choices are linked with better health, but many current interventions to improve diet have limited effect. We tested the hypothesis that providing personalized nutrition (PN) advice based on information on individual diet and lifestyle, phenotype and/or genotype would promote larger, more appropriate, and sustained changes in dietary behaviour. Methods: Adults from seven European countries were recruited to an internet-delivered intervention (Food4Me) and randomized to: (i) conventional dietary advice (control) or to PN advice based on: (ii) individual baseline diet; (iii) individual baseline diet plus phenotype (anthropometry and blood biomarkers); or (iv) individual baseline diet plus phenotype plus genotype (five diet-responsive genetic variants). Outcomes were dietary intake, anthropometry and blood biomarkers measured at baseline and after 3 and 6 months’ intervention. Results: At baseline, mean age of participants was 39.8 years (range 18–79), 59% of participants were female and mean body mass index (BMI) was 25.5 kg/m2. From the enrolled participants, 1269 completed the study. Following a 6-month intervention, participants randomized to PN consumed less red meat [-5.48 g, (95% confidence interval:-10.8,-0.09), P = 0.046], salt [-0.65 g, (−1.1,-0.25), P = 0.002] and saturated fat [-1.14 % of energy, (−1.6,-0.67), P < 0.0001], increased folate [29.6 µg, (0.21,59.0), P = 0.048] intake and had higher Healthy Eating Index scores [1.27, (0.30, 2.25), P = 0.010) than those randomized to the control arm. There was no evidence that including phenotypic and phenotypic plus genotypic information enhanced the effectiveness of the PN advice. Conclusions: Among European adults, PN advice via internet-delivered intervention produced larger and more appropriate changes in dietary behaviour than a conventional approach.

10 December 2014 in Genes & Nutrition
Verified
Journal Article
Open access
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Carlos Celis-MoralesCarlos Celis-Morales
Carlos Celis-Morales
KLKatherine Livingstone
Katherine Livingstone
CMCyril F. M. Marsaux
Cyril F. M. Marsaux
HFHannah Forster
Hannah Forster
COClare B. O’donovan
Clare B. O’donovan
JMJohn Mathers
John Mathers
Improving lifestyle behaviours has considerable potential for reducing the global burden of non-communicable diseases, promoting better health across the life-course and increasing well-being. However, realising this potential will require the development, testing and implementation of much more effective behaviour change interventions than are used conventionally. Therefore, the aim of this study was to conduct a multi-centre, web-based, proof-of-principle study of personalised nutrition (PN) to determine whether providing more personalised dietary advice leads to greater improvements in eating patterns and health outcomes compared to conventional population-based advice. A total of 5,562 volunteers were screened across seven European countries; the first 1,607 participants who fulfilled the inclusion criteria were recruited into the trial. Participants were randomly assigned to one of the following intervention groups for a 6-month period: Level 0—control group—receiving conventional, non-PN advice; Level 1—receiving PN advice based on dietary intake data alone; Level 2—receiving PN advice based on dietary intake and phenotypic data; and Level 3—receiving PN advice based on dietary intake, phenotypic and genotypic data. A total of 1,607 participants had a mean age of 39.8 years (ranging from 18 to 79 years). Of these participants, 60.9 % were women and 96.7 % were from white-European background. The mean BMI for all randomised participants was 25.5 kg m−2, and 44.8 % of the participants had a BMI ≥ 25.0 kg m−2. Food4Me is the first large multi-centre RCT of web-based PN. The main outcomes from the Food4Me study will be submitted for publication during 2015.

15 December 2017 in Genes & Nutrition
Verified
Journal Article
Open access
PDF file
KGKeith Grimaldi
Keith Grimaldi
BOBen van Ommen
Ben van Ommen
JOJosé M Ordovás
José M Ordovás
LPLauence Parnell
Lauence Parnell
JMJohn Mathers
John Mathers
JBJildau Bouwman
Jildau Bouwman
Nutrigenetic research examines the effects of inter-individual differences in genotype on responses to nutrients and other food components, in the context of health and of nutrient requirements. A practical application of nutrigenetics is the use of personal genetic information to guide recommendations for dietary choices that are more efficacious at the individual or genetic subgroup level relative to generic dietary advice. Nutrigenetics is unregulated, with no defined standards, beyond some commercially adopted codes of practice. Only a few official nutrition-related professional bodies have embraced the subject, and, consequently, there is a lack of educational resources or guidance for implementation of the outcomes of nutrigenetic research. To avoid misuse and to protect the public, personalised nutrigenetic advice and information should be based on clear evidence of validity grounded in a careful and defensible interpretation of outcomes from nutrigenetic research studies. Evidence requirements are clearly stated and assessed within the context of state-of-the-art ‘evidence-based nutrition’. We have developed and present here a draft framework that can be used to assess the strength of the evidence for scientific validity of nutrigenetic knowledge and whether ‘actionable’. In addition, we propose that this framework be used as the basis for developing transparent and scientifically sound advice to the public based on nutrigenetic tests. We feel that although this area is still in its infancy, minimal guidelines are required. Though these guidelines are based on semi-quantitative data, they should stimulate debate on their utility. This framework will be revised biennially, as knowledge on the subject increases.

1 August 2016 in The American Journal of Clinical Nutrition
Verified
Journal Article
Open access
PDF file
OSon behalf of the Food4Me Study
on behalf of the Food4Me Study
KLKatherine Livingstone
Katherine Livingstone
Carlos Celis-MoralesCarlos Celis-Morales
Carlos Celis-Morales
Santiago Navas-CarreteroSantiago Navas-Carretero
Santiago Navas-Carretero
RSRodrigo San-Cristobal
Rodrigo San-Cristobal
JMJohn Mathers
John Mathers
Background: Little is known about the efficacy of personalized nutrition (PN) interventions for improving consumption of a Mediterranean diet (MedDiet

1 May 2017 in The American Journal of Clinical Nutrition
Verified
Journal Article
Open access
PDF file
Carlos Celis-MoralesCarlos Celis-Morales
Carlos Celis-Morales
CMCyril Fm Marsaux
Cyril Fm Marsaux
KLKatherine Livingstone
Katherine Livingstone
Santiago Navas-CarreteroSantiago Navas-Carretero
Santiago Navas-Carretero
RSRodrigo San-Cristobal
Rodrigo San-Cristobal
JMJohn Mathers
John Mathers
Background: There has been limited evidence about whether genotype-tailored advice provides extra benefits in reducing obesity-related traits compared

1 July 2013 in Appetite
Verified
Journal Article
Open access
BSBarbara J Stewart-Knox
Barbara J Stewart-Knox
SKSharron Kuznesof
Sharron Kuznesof
JRJenny Robinson
Jenny Robinson
ARAudrey Rankin
Audrey Rankin
KOKaren Orr
Karen Orr
LFLynn J. Frewer
Lynn J. Frewer
The aim of this research was to explore consumer perceptions of personalised nutrition and to compare these across three different levels of "medicalization": lifestyle assessment (no blood sampling); phenotypic assessment (blood sampling); genomic assessment (blood and buccal sampling). The protocol was developed from two pilot focus groups conducted in the UK. Two focus groups (one comprising only "older" individuals between 30 and 60 years old, the other of adults 18-65 yrs of age) were run in the UK, Spain, the Netherlands, Poland, Portugal, Ireland, Greece and Germany (N=16). The analysis (guided using grounded theory) suggested that personalised nutrition was perceived in terms of benefit to health and fitness and that convenience was an important driver of uptake. Negative attitudes were associated with internet delivery but not with personalised nutrition per se. Barriers to uptake were linked to broader technological issues associated with data protection, trust in regulator and service providers. Services that required a fee were expected to be of better quality and more secure. An efficacious, transparent and trustworthy regulatory framework for personalised nutrition is required to alleviate consumer concern. In addition, developing trust in service providers is important if such services to be successful.