Carolyn,
British blackcurrants are bred to be black, and therefore contain higher levels of anthocyanins. You may have guessed, they close the Blood brain barrier!!
SEE http://www.medicalnewstoday.com/medi...p?newsid=36488
Ron
British Blackcurrants Could Prevent Alzheimer's Disease
Main Category: Alzheimer's / Dementia News
Article Date: 24 Jan 2006 - 10:00

Research news in the Journal of the Science of Food and Agriculture Compounds in blackcurrants could prevent Alzheimer's disease and the characteristics of British berries suggest they do it best, writes Jennifer Rohn in Chemistry & Industry magazine.

New research led by Dilip Ghosh of the Horticulture and Food Research Institute in New Zealand, shows that compounds in blackcurrants have a potent protective effect in cultured neuronal cells against the types of stress caused by dopamine and amyloid-b, a peptide associated with Alzheimer's disease.

'These compounds also work in hippocampal cells taken straight from the brain,' researcher James Joseph of Tufts University told Chemistry & Industry. Joseph says that the effect will likely be reproduced in the human body and that blackcurrants could help prevent or significantly delay the onset of Alzheimer's.

Blackcurrants and boysenberries, more common in the US, both contain anthocyanins and polyphenolics. British blackcurrants are bred to be darker, which means they have more anthocyanins and are likely to be more potent.

Compounds from these berries are already known to act as antioxidants, but a role in neuroprotection has not been demonstrated previously, according to the researchers.

The mechanism of action is unclear. But James said: 'We have evidence that the compounds protect against Alzheimer's by influencing the early gene expression in learning and memory, which influences cell signaling pathways that help neuronal cells communicate with each other.'

Dilip's team recently demonstrated the potent protective effect of blackcurrant compounds on cultured human promyeloyte and neuroblastoma cells assaulted by hydrogen peroxide (JSFA doi: 10.1002/jsfa.0247).

Article: "Effects of anthocyanins and other phenolics of boysenberry and blackcurrant as inhibitors of oxidative stress and damage to cellular DNA in SY-SY5Y and HY-60 cells" by D. Ghosh et. al JSFA, 10.1002/jsfa.2409.

ALSO Bilbrries close the BBB

Bilberry extract

http://www.lef.org/magazine/mag2000/mar00-cover1a.html

In addition, bilberry extract has been shown to enhance the blood-
brain barrier, which tends to become impaired with aging, showing a
decrease in vascular density, increased permeability and other
abnormalities. The normal functioning of blood-brain barrier is
important not only for keeping out toxins and undesirable compounds,
but also for glucose transport to the brain. Anthocyanins and
related compounds seem able to decrease capillary permeability
(possibly by stabilizing membrane phospholipids). Animal studies
have also shown that if the blood-brain barrier becomes damaged and
too permeable, anthocyanins help restore normal permeability