title: Effect of Flavonoids on Oxidative Stress and Inflammation in Adults at Risk of Cardiovascular Disease: A Systematic Review.
abstract: Oxidative stress (OS) and inflammatory processes initiate the first stage of cardiovascular disease (CVD). Flavonoid consumption has been related to significantly improved flow-mediated dilation and blood pressure. Antioxidant and anti-inflammatory mechanisms are thought to be involved. The effect of flavonoids on markers of oxidative stress and inflammation, in at risk individuals is yet to be reviewed. Systematic literature searches were conducted in MEDLINE, Cochrane Library, CINAHL and SCOPUS databases. Randomised controlled trials in a Western country providing a food-based flavonoid intervention to participants with one or two modifiable risk factors for CVD measuring a marker of OS and/or inflammation, were included. Reference lists were hand-searched. The Cochrane Collaboration Risk of Bias Tool was used to assess study quality. The search strategy retrieved 1248 articles. Nineteen articles meeting the inclusion criteria were reviewed. Eight studies were considered at low risk of bias. Cocoa flavonoids provided to Type 2 diabetics and olive oil flavonoids to mildly-hypertensive women reduced OS and inflammation. Other food sources had weaker effects. No consistent effect on OS and inflammation across patients with varied CVD risk factors was observed. Study heterogeneity posed a challenge for inter-study comparisons. Rigorously designed studies will assist in determining the effectiveness of flavonoid interventions for reducing OS and inflammation in patients at risk of CVD.
authors.affiliation: Nutrition and Dietetics, School of Health Sciences, Flinders University, GPO Box 2100, Adelaide 5001, Australia. jenni.suen@flinders.edu.au.
authors.forename: Jenni
authors.initials: J
authors.lastname: Suen
authors.affiliation: Nutrition and Dietetics, School of Health Sciences, Flinders University, GPO Box 2100, Adelaide 5001, Australia. jm.thomas@flinders.edu.au.
authors.forename: Jolene
authors.initials: J
authors.lastname: Thomas
authors.affiliation: Nutrition and Dietetics, School of Health Sciences, Flinders University, GPO Box 2100, Adelaide 5001, Australia. amelia.kranz@flinders.edu.au.
authors.forename: Amelia
authors.initials: A
authors.lastname: Kranz
authors.affiliation: Department of Vascular Surgery, School of Medicine, Flinders University, GPO Box 2100, Adelaide 5001, Australia. drsvun@gmail.com.
authors.forename: Simon
authors.initials: S
authors.lastname: Vun
authors.affiliation: Nutrition and Dietetics, School of Health Sciences, Flinders University, GPO Box 2100, Adelaide 5001, Australia. michelle.miller@flinders.edu.au.
authors.forename: Michelle
authors.initials: M
authors.lastname: Miller
keywords: antioxidant; cocoa; dietary intervention; olive oil; polyphenol; prevention