The key finding is a recent study indicates that consuming purple colored fruit can keep off age-related diseases such as Alzheimer's, heart problems and cancer at last.
The study, conducted by the University of Manchester, suggests that the odds of developing multiple sclerosis and Parkinson's disease may also be reduced by consuming blueberries, blackberries, blackcurrants or plums.
Researchers say one or two of the recommended five daily portions of fruit and vegetable should be purple fruit.
It is thought that a compound in purple fruit helps fight the harmful effects of iron, which can damage cells if it makes its way through the digestive system in the wrong form.
"We normally think of iron as something that is good for us. And, in the right form, it is. But in the wrong form it is not good for you because what it does is react with things that are always knocking around in the body to make something very nasty indeed," the Daily Mail quoted lead researcher Professor Douglas Kell as saying.
Too much free iron could also stop vitamin C from helping the body fend off infections.
The study appears in the journal Archives of Toxicology.