Using a mouse model, a team of medical scientists in the Department of Human Physiology, headed by Professor Xin-Fu Zhou [pictured right], has found that adding grape seed extract to the diet acts to prevent the formation of deposits of amyloid proteins in the brain.
Professor Zhou said that over-production of amyloid-beta proteins, or the body’s failure to degrade them, leads to the formation of clumps or snarls in the brain and is a major cause of Alzheimer’s disease.
“This aggregation of amyloid will cause loss of nerve connections, cell death and inflammation in the brain, leading to cognitive decline,” Professor Zhou said.
Many fruits and vegetables contain polyphenols – complex molecules with anti-oxidant properties – and some have been identified by scientists as a possible method for reducing amyloid deposition.
Professor Zhou’s team, in collaboration with researchers from CSIRO, chose to experiment with the polyphenol extract from grape seeds, a resource in which South Australia is particularly rich.
Grape seed extract was fed to mice affected by transgenic Alzheimer’s for six months, after which the researchers observed their behaviour and brain pathology, comparing them with a control group.
“We found that grape seed extract was a very powerful agent in reducing amyloid-beta deposits in the brain. It also produced marginal improvements in cognitive function and, most importantly, reduced inflammation,” Professor Zhou said.
He said that the CSIRO team led by Dr Michael Fenech found that grape seed extract also prevented DNA damage by amyloids in the same mouse model.
“In general, grape seed extract demonstrates a strong disease-modifying effect,” Professor Zhou said.
Because mice are comparable to humans in physiological and behavioural terms, the grape seed extract is potentially an effective preventive measure against the development of Alzheimer’s.
“As a dietary supplement, the effect of grape seeds is significant and beneficial; it is a safe, natural product which contains ‘goodies’ that we shouldn’t throw away.”
Lead researcher Dr Yanjiang Wang said that moderate wine consumption is already recommended to prevent Alzheimer’s disease, but since the disease mainly afflicts elderly people, many of whom cannot or will not drink alcohol, grape seed extract is a better choice to prevent the disease.
The study’s findings will be published shortly, and Dr Wang will also present the results to the Society for Neuroscience annual conference in Washington DC in November. The team is now seeking funding to enable further research that aims to identify the specific active compounds in grape seeds.