title: The impact of diet quality scores and dietary patterns on cardiometabolic risk biomarkers in UK adults
Creators: name: Yilmaz, Arife
Publisher: name: University of Reading
Year: 2024

description: Enhancing diet quality remains a critical public health priority due to its significant impact 
on cardiometabolic disease (CMD) development and 40% of the deaths globally 
attributed to unhealthy dietary habits. The APOLIPOPROTEIN (APO)E gene plays a 
critical role in lipid metabolism, and its genetic variants, particularly the APOE E4 allele, 
have been associated in some studies with an increased risk of cardiovascular disease 
(CVD) compared to the wild-type E3/E3 homozygotes. This PhD project aimed to 
explore the association between adherence to higher-quality diets, assessed through 
established and novel diet quality scores (DQS), as well as empirically derived dietary 
patterns, and risk factors for CMD in disease-free UK adults. Furthermore, investigations
into how the APOE genotype interacted with diet quality to influence CMD risk markers
was completed.
A scoping review using a systematic approach was undertaken (Chapter-2) to determine 
commonly used DQS to assess the association between diet quality and CMD risk 
markers in healthy adults. Healthy Eating Index-2010 (HEI), Alternate HEI-2010, 
modified Mediterranean Diet Score, alternate Mediterranean Diet Score (aMED), and 
Dietary approach to stop hypertension score (DASH) were identified as commonly used 
DQS from the 47 studies described in the 57 publications identified. It was hypothesised 
(Chapter 3) that a novel UK specific DQS (eNutri) would be more superior than the HEI�2015, aMED, and DASH score in determining the relationship between diet quality and 
CMD risk. While the eNutri-DQS showed similar associations with anthropometrics, 
blood lipids, and diastolic blood pressure (DBP) as the other scores, it emerged as the 
only DQS associated with the arterial stiffness index (digital volume pulse). Additionally, 
the DASH score was the only DQS that was inversely associated with total cholesterol 
and low-density lipoprotein cholesterol. Using principal component analysis two main 
dietary patterns (DP) were identified (Chapter 4), explaining 11.7% of the total variance 
of food intake among UK adults. DP1 rich in fermented dairy, wholegrains, fruits, and 
vegetables, and lower intakes of red and processed meat products was associated with 
lower body mass index, waist circumference, triacylglycerol and DBP, as well as higher 
high-density lipoprotein cholesterol (HDL-C). DP2 characterised by high consumption 
of sugars and refined grains, was associated with lower HDL-C. Finally, in Chapter 5, the 
role of APOE genotype on the relationship between eNutri-DQS and CMD risk factors
was determined. Compared to wild-type E3/E3 group, higher diet quality was associated 
with lower central adiposity, favourable body fat distribution, and lower fasting glucose
(E4 only) in E2 and E4 carriers.
To conclude, higher diet quality and greater adherence to DP1, broadly aligned with UK 
dietary guidelines, may be associated with a more favourable cardiometabolic health 
profile in UK adults. The eNutri-DQS emerged as a useful tool for evaluating the 
relationship between diet quality in future CMD risk, with a potential role of APOE
genotype on this relationship.