Increasing fruit and vegetable intake has no effect on retinal vessel caliber in adults at high risk of developing cardiovascular disease

- The effect of dietary factors on the microvasculature is not clear.
- The short-term effect of fruit and vegetables on retinal vessels was measured.
- Increasing fruit and vegetables improved micronutrient status.
- There was no effect of increasing fruit and vegetable intake on retinal vessel caliber.

Background and aimRetinal vessel abnormalities are associated with cardiovascular disease (CVD) risk. To date, there are no trials investigating the effect of dietary factors on the retinal microvasculature. This study examined the dose response effect of fruit and vegetable (FV) intake on retinal vessel caliber in overweight adults at high CVD risk.Methods and resultsFollowing a 4 week washout period, participants were randomized to consume either 2 or 4 or 7 portions of FV daily for 12 weeks. Retinal vessel caliber was measured at baseline and post-intervention. A total of 62 participants completed the study. Self-reported FV intake indicated good compliance with the intervention, with serum concentrations of zeaxanthin and lutein increasing significantly across the groups in a dose-dependent manner (P for trend < 0.05). There were no significant changes in body composition, 24-h ambulatory blood pressure or fasting blood lipid profiles in response to the FV intervention. Increasing age was a significant determinant of wider retinal venules (P = 0.004) whereas baseline systolic blood pressure was a significant determinant of narrower retinal arterioles (P = 0.03). Overall, there was no evidence of any short-term dose-response effect of FV intake on retinal vessel caliber (CRAE (P = 0.92) or CRVE (P = 0.42)).ConclusionsThis study demonstrated no effect of increasing FV intake on retinal vessel caliber in overweight adults at high risk of developing primary CVD.Clinical trial registrationNCT00874341.