“Under our experimental conditions, the wild blueberry drink reduced the level of oxidized DNA bases and increased the protection from the ex vivo [hydrogen peroxide] H2O2-induced DNA damage,”wrote researchers from Universita degli Studi di Milano (Italy) and The University of Maine (USA).
“These results were particularly evident in the group of smokers/ex-smoker subjects with respect to non-smokers.
“This effect on DNA damage may be dependent on phytochemicals present in the wild blueberry drink that can exert a direct protective effect against oxidative insult by scavenging reactive oxygen species in blood.”
The wild blueberry juice provided daily doses of anthocyanins of 375 milligrams.
Study details
The researchers recruited men with an average age of 48 and with at least one risk factor for cardiovascular disease (CVD) to participate in their six week study. Participants consumed a daily glass of wild blueberry juice or placebo for six weeks.
Results showed that DNA damage in white blood cells was reduced from 12.5 to 9.6% following daily consumption of the blueberry juice for six weeks, while no changes were observed in the placebo group.
In addition, when blood cells were exposed to H2O2, DNA damage was reduced from 45.8 to 37.2 % in the juice group. Again, no changes were observed in the placebo group.
However, no changes were observed in any of the other variable measured, including inflammatory markers, and the function of cells lining blood vessels (endothelial cells).
“This indicates that regular consumption of wild blueberries can reduce oxidative stress in a relevant cell population in the blood, even though peripheral arterial function and the other variables studied here were not significantly affected,”wrote the researchers.
“Future larger studies with a homogeneous population for CVD risk factors are necessary to understand the duration of exposure to anthocyanins and the dose and/or the form of the wild blueberry product that may be effective in modulating endothelial function and the other parameters studied,” they concluded.
Published online ahead of print, Online First, doi: 10.1007/s00394-012-0402-9
“Effect of a wild blueberry (Vaccinium angustifolium) drink intervention on markers of oxidative stress, inflammation and endothelial function in humans with cardiovascular risk factors”
Authors: P. Riso, D. Klimis-Zacas, C. Del Bo, D. Martini, J. Campolo, et al.
