Consumption of the fruit beverages led to an 11 per cent reduction in the levels of C-reactive protein (CRP), a protein produced in the liver and is a known marker for inflammation, according to findings published in the British Journal of Nutrition.
Increased levels of CRP are a good predictor for the onset of both type-2 diabetes and cardiovascular disease.
“The use of blackcurrant and orange juices reduces the level of the inflammatory markers CRP and fibrinogen in patients with [peripheral arterial disease] compared to a sugar-containing beverage while no effect of vitamin E was observed,” wrote lead author Christine Dalgard from the University of Southern Denmark's Institute of Public Health.
Dr Dalgard told BeverageDaily.com that the design of her study didn’t allow for an elucidation of the specific active component - if indeed a single component could have been the cause. “I would suggest that it is the mixture of several agents in fruit and vegetables, here notable fruit juices, that affect the arterial wall, thus patients - or healthy - are better of eating 'whole' fruits and vegetables (juices) than specific supplements,” she said.
Study details
The researchers conducted a randomised, cross-over trial to study the effect of a daily orange and blackcurrant juice (500 ml) or vitamin E (15 mg RRR-alpha-tocopherol) supplements on markers of inflammation.
Forty-eight people with peripheral arterial disease (PAD) were randomly assigned to receive two dietary supplements from four possible combinations, including juice plus vitamin E, juice plus placebo, sugar drink plus vitamin E, or the sugar drink plus placebo.
Participants consumed the combinations for 28 days, with four weeks separating the interventions.
At the end of the study, an 11 and 3 per cent reduction in levels of CRP and fibrinogen were observed following juice consumption, while the sugar drink was associated with a 13 and 2 per cent increase in CRP and fibrinogen levels, respectively.
Supplementation with vitamin E was reported to have produced no significant effects on the inflammation markers.
“In this study, orange and blackcurrant juice reduced markers of inflammation, but not markers of endothelial activation, in patients with peripheral arterial disease, relative to sugar drinks,” concluded Dalgard and her co-workers.
Dr Dalgard said that she was no longer studying patients with peripheral arterial disease, but observational studies on risk markers for cardiovascular disease, including inflammatory markers and diet, are underway.
Source: British Journal of NutritionJanuary 2009, Volume 101, Pages 263-269 doi:10.1017/S0007114508995660"Supplementation with orange and blackcurrant juice, but not vitamin E, improves inflammatory markers in patients with peripheral arterial disease"Authors: C. Dalgard, F. Nielsen, J.D. Morrow, H. Enghusen-Poulsen, T. Jonung, M. Horder, M.P.M. de Maat