Omega-3 fatty acids in diet help maintain zinc level in brain, crucial to mental health, say Australian researchers.
"Previous research has suggested that there is a link between low levels in the brain of the omega-3 fatty acid DHA - docosahexaenoic acid to give it its full name - and Alzheimer's disease," explained Deakin University cellular biologist and project leader, Professor Leigh Ackland.
"Also, the incidence of neurodegenerative diseases such as Alzheimer's appears to be reduced in populations with a high omega-3 fatty acid diet."
Professor Ackland said she and her colleagues looked specifically at the relationship between DHA and zinc in the brain's neuronal cells - the cells responsible for transmitting signals in the brain.
"We found that when the level of DHA in neuronal cells drops, the level of zinc rises. The higher levels of zinc can be toxic, resulting in cell death. This type of cell death is a key feature of neurodegenerative diseases, including Alzheimer's.
"We believe that having omega-3 fatty acids in the diet helps keep the levels of zinc in the brain in balance and helps prevents the increase in levels that triggers cell death," Professor Ackland said.
The findings of Professor Ackland and her Deakin colleagues have been published in the international molecular biosciences journal FEBS Letters
(Volume 584, Issue 3, Pages 612-618, 5 February 2010).
"Although it has been known that DHA is essential for healthy brain function, to the best of our knowledge this is the first time a direct link has been demonstrated between the levels of DHA and zinc in the brain's neuronal cells," Professor Ackland said.
"Alzheimer's disease is a complex disorder and it is unclear what causes it, although dietary factors are implicated in its development. Our work provides insights into how fatty acid nutrition may prevent the development of Alzheimer's and could lead to new treatments that prevent zinc-induced brain damage.
"Future studies will be directed to understanding the details of the mechanisms by which DHA controls zinc in the brain."