Abstract/Summary

Cardiovascular diseases (CVD) remain one of the leading causes of morbidity and mortality worldwide. Current dietary guidelines advocate for a restriction of high intakes of saturated fatty acids (SFA), an important risk factor for the development of CVD due to their association with increased low-density lipoprotein cholesterol (LDL-C). Dairy foods are major contributors of total SFA intake. The literature review explored aspects of dairy consumption on CVD risk, highlighting current evidence which suggests a beneficial effect of certain dairy products. A reduction of dietary SFA is also dependent on a suitable replacement macronutrient. Supplementation of the dairy cow diet with plant oils/seeds provides an alternative strategy to partially replacing SFA in milk fat with monounsaturated fatty acids (MUFA). Few interventions studies have extensively investigated the impact of fatty acid (FA) modified dairy products on traditional and novel CVD risk markers. The RESET intervention study aimed to address this knowledge gap in both a chronic and acute-withinchronic setting in adults at moderate CVD risk. A food-exchange model (38% total energy (%TE) from fat) was implemented and adherence assessed from 4 day weighed food diaries and phospholipid FA (PL-FA) analysis. Consumption of the FA-modified diet for 12 weeks (dietary target: 16%TE SFA; 14%TE MUFA) led to a significant attenuation in fasted LDL-C concentrations from baseline values and compared to matched control products (19%TE SFA; 11%TE MUFA). At the beginning and end of each dietary intervention, the postprandial investigation was performed using sequential test meals representative of the assigned dairy diet. Following the FA-modified diet and test meals, a decrease in the postprandial iAUC summary response for apolipoprotein B (apoB) was observed, suggestive of an effect on triacylglyceride-rich lipoproteins (TRL). Changes in postprandial summary responses of plasma total lipid FA reflected the intake of the test meals. Additionally, the FA-modified diet appeared to modestly impact on both fasted concentrations and postprandial responses of nitrite, which may be indicative of an effect on endothelial function. Little to no impact was observed for other outcome measures. The impact of APOE genotype, retrospectively assessed, fasted and postprandial outcome measures following the two dairy diets, was explored. Significant pre-intervention fasted baseline differences in high-density lipoprotein cholesterol (HDL-C), small and medium HDL particle distribution and non-esterified fatty acids (NEFA) between E4 carriers and E3/E3, were observed. There was no interaction between genotype and treatment on any of the outcome measures. In summary, consumption of FA-modified dairy products appear to beneficially impact on certain markers of CVD risk, compared to matched control products. However, further research should address the impact of other types of FA-modified dairy products in both healthy and at risk populations.