Top American scientists have found old people can protect themselves against Alzheimer's disease if they eat significant amounts of peanuts, berries and grapes.

A new study published in the Journal of Biological Chemistry has shown compounds abundantly found in these foods lower levels of amyloid-beta peptides, a chemical that can lead to the onset of Alzheimer's disease. The compound called resveratrol is responsible for breaking down these peptides.

Furthermore, scientists suggest eating a combination of these foods increases capacity to resist the disease. Study author Philippe Marambaud said: "…several compounds work in synergy with small amounts of resveratrol to slow down the progression of the neurodegenerative process in humans."