Blueberries and green tea 'help fight Alzheimer's'

Both contain nutrients known as iron chelators which bind tightly to the metallic substance.

Scientists believe poorly bound iron leads to the production of free radical toxins that can cause degenerative diseases. Brightly coloured fruits and vegetables are good sources of iron chelators, as is green tea, say the researchers.

Purple fruits such as blueberries are the best at holding on to iron effectively.

Prof Douglas Kell, from the University of Manchester, who led the research, reported his findings in the journal Archives of Toxicology.