The association between alcohol consumption and cardiometabolic disease risk has been described as a J or U-shaped curve attributed to a combination of harmful and beneficial effects varying with volume of intake. Diet is an established risk factor for cardiometabolic disease and related traits However, few studies examining this association adequately control for residual confounding by dietary intake. Therefore, the aim of this thesis was to investigate the relationship between alcohol consumption and markers of cardiometabolic health independent of dietary intake.
Cross sectional analyses were conducted using data from the Airwave Health Monitoring Study – a British occupational cohort (n = 9,581). Alcohol consumption behaviour was determined from questionnaire and 7-day diet record data. Diet quality was determined by measuring adherence to the Dietary Approaches to Stop Hypertension (DASH) diet using data from the 7-day diet records. Markers of cardiometabolic health included: adiposity (body mass index and waist circumference), blood pressure, cholesterol, HbA1c and C-reactive protein. All analyses were replicated in an independent UK cohort using UK Biobank data (n =146,888). As part of this thesis, genetic analyses were conducted to investigate whether genes implicated in the regulation of HDL-c may facilitate some of the cardioprotective effects attributed to alcohol intake.
Heavy alcohol consumption is associated with a deterioration in cardiometabolic health. The risk of cardiometabolic disease as indicated by a cardiometabolic risk score was lowest amongst moderate drinkers and highest amongst never, and heavy drinkers. Increasing alcohol intake was associated with a deterioration in diet quality and had an additive effect of total energy intake. Diet quality did not modify the relationship between moderate alcohol intake and cardiometabolic risk. Alcohol intake did not alter the effect of genes implicated in the regulation of HDL-c. These findings were validated in a sub-sample of the UK Biobank cohort.
To conclude, the findings from this thesis show that alcohol consumption plays a key role in determining diet quality and cardiometabolic risk. Specifically, risk of developing obesity.