July 13, 2012
Wild Blueberries Protect Against Cardiovascular and DNA Damage
New data suggests that wild blueberries may reduce oxidative damage to DNA and decrease the risk of cardiovascular and degenerative diseases.
Blueberry consumption has previously been linked to reduced risk of Alzheimer's, and the beneficial effects of the blueberries are thought to be linked to their flavonoid content - in particular anthocyanins and flavanols. The exact way in which flavonoids affect the brain are unknown, but they have previously been shown to cross the blood brain barrier after dietary intake.
It is believed that they may exert their effects on learning and memory by enhancing existing neuronal connections, improving cellular communications and stimulating neuronal regeneration.
A previous study published in the Journal of Agricultural and Food Chemistry showed that animals fed a diet supplemented with 8 percent wild blueberries experienced less constriction in blood vessel, compared with animals fed a control diet.
In the most recent study, DNA damage in 18 male volunteers was reduced from 12.5 to 9.6% following daily consumption of an anthocyanin-rich blueberry juice for six weeks, according to findings published in the European Journal of Nutrition.
"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.
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.
April McCarthy is a community journalist playing an active role reporting and analyzing world events to advance our health and eco-friendly initiatives.
European Journal of Nutrition