The Effect and Acceptability of Increased Whole Apple Consumption, Apple Extract and Freeze-Dried Apple Pieces on Biomarkers of CVD Risk: The APPS Pilot Study

Abstract

An increased intake of fruit and vegetables has been associated with decreased risk of cardiovascular disease (CVD). However, it is currently unclear as to whether particular fruits and vegetables convey more benefit than others, and if the form in which a particular fruit or vegetable is delivered, for example, depending on polyphenol content or the degree of processing, affects potential health benefits. The aim of this study was to conduct a pilot randomised placebo-controlled trial (RCT) with the ultimate aim of assessing if different apple products differentially affect CVD risk factors. The RCT was conducted in those at elevated risk of CVD. Participants were randomised to receive high polyphenol apples, low polyphenol apples, capsules containing apple extract, dried apple pieces or placebo capsules to take for four weeks. A range of risk factors and biomarkers associated with CVD were measured before and after the intervention period. A total of 55 participants were randomised and completed the study. Change in hip circumference was significantly different across the groups after 4 weeks (P=0.02) Change in fibre intake was also statistically significant between groups, with those consuming high polyphenol apples having a higher intake than those on the apple extract (P=0.01). There was a significant within-group change in fasting oxidised LDL in the apple extract group (P=0.008). A significant difference in change in volume-corrected epicatechin was observed (P=0.03), with those on apple extract having higher levels than those on placebo capsule (P=0.002) or low polyphenol apples (P=0.01) Overall, interventions were generally acceptable to participants. Apple products appeared to have a positive effect on some risk factors for CVD in this pilot study, which indicated a definitive RCT is feasible. Further adequately powered studies need to be conducted to definitively test these findings.