Genetic Epidemiology: Food preferences genetics and its impact on food consumption and human health

***Background***
It is commonly agreed that nutrition is one of the most important factors influencing human health. In particular, long-term exposure to unhealthy food behaviours may lead to several disorders such as obesity, metabolic syndrome, cardiovascular disease and some cancers. Although up to now many studies have focused on the genetics of these disorders, only recently have geneticists started looking at food intake, although with very limited results. In countries where food availability is not an issue, food preference is one of the most important factors driving food choice and consumption. Recent studies suggest that food liking measures are better predictors of actual long-term consumption compared to self-reported food frequency questionnaire.

***Aims***
The proposed PhD studentship has the objective of understanding the genetic bases of food preferences as markers of actual long-term consumption, and evaluate their impact on health and disease.
The studentship will concentrate on one or more of the following objectives:

1) Genome-wide association analysis of food preferences.

Given the availability of extensive food liking questionnaires and genome-wide genotypes on numerous large cohorts of samples from Europe and countries along the Silk Road, genome-wide association meta-analysis (GWAMA) will be conducted to identify the genes underlying food preferences. Single foods will be grouped according to sensory qualities (ie. bitter, sour), commodity classes (ie. vegetables) or nutritional content (ie. protein, unsaturated fats) and an overall index will be estimated for the association analysis. A preliminary epidemiological study aimed at understanding the relationship between the food preference measures and other health related traits will be conducted.
The GWAMA will illuminate the heritability of food-liking, provide association statistics for downstream applications with genetic risk scores (GRS) and critically, novel genome-wide significant loci will illuminate the underlying biology of food preferences, a long neglected area.

2) Evaluation of causal relationships between food liking and clinical outcomes through the use of genetic risk scores.

The second topic will be to assess the causal impact of food liking on a number of outcomes of public health importance including metabolic syndrome and its components, as well as cardiovascular events. The genetic variants discovered for the food liking will be used to create a GRS that predicts food preferences. It will thus be possible to evaluate the impact of these GRS on the disease outcomes on available large cohorts such as Generation Scotland or UK Biobank highlighting causal lifestyle-health relationships 3.


***Training outcomes***

Given the multidisciplinary nature of the proposed project the successful candidate will have the chance to work on a wide range of fields including:
• General epidemiology
• Handling / of questionnaire data.
• Quality control and association analysis of genetic data.
• Handling genetic data from isolated populations; large scale genetic data handling in general.
• Multi-trait genetic association analysis
• Estimation of genetic risk scores and their use for establishing causal risk factor-endpoint relationships


Supervisors
• Dr Jim Wilson
• Dr Nicola Pirastu


References
1. Pirastu N et al. A Genome-Wide Association
Study in isolated populations reveals new genes associated to common food
likings. Rev Endocr Metab Disord. 2016 Apr 30.

2. Pirastu N et al. Genome-wide association analysis on five isolated populations identifies variants of the HLA-DOA gene associated with white wine liking. Eur J Hum Genet. 2015 Dec;23(12):1717-22.

***Requirements:***

Applicants should have or be predicted to obtain 2:1 or higher in relevant undergraduate degree.
Relevant post-graduate degree, or equivalent if outside the UK is desirable.
Applicants must meet entry requirements (including English language proficiency) for acceptance onto the Usher Institute’s PhD programme.

Following interview, the selected candidate will need to apply and be accepted for a place on the Usher Institute Population Health Sciences PhD programme. Details about the PhD programme can be found here: http://www.ed.ac.uk/studying/postgraduate/degrees?r=site/view&id=213&cw_xml

Interested candidates with a background in genetics, statistics or computation should initially enquire to Nicola Pirastu: [Email Address Removed] .


***Application procedure:***

Please provide the following in electronic format by email to [Email Address Removed]

• CV
• Personal statement indicating how you meet the criteria for this studentship
• Degree certificate / marks
• 2 academic references


Interviews will be held in Edinburgh (or be conducted by videoconference / Skype).

Closing date for applications: 5pm 7 April 2017.