A diet rich in fruit juice could cut the risk of Alzheimer's disease and other diseases, according to research.
Grape juice was found to be one of the most beneficial juices
A team at Glasgow University has carried out one of the first studies into the benefits of antioxidants.
The study found that grape, apple and cranberry juices contained high amounts of the beneficial chemicals.
Antioxidants are natural chemicals which reduce cell damage caused by free radicals, a major cause of disease and ageing.
Researchers from the Human Nutrition group at Glasgow University examined different juices and how much antioxidant they contained as well as the different chemical compounds.
Polyphenols are a very strong antioxidant that get rid of free radicals in the body.
It is believed they can maintain and improve health and also protect against chronic diseases.
Results showed purple grape juice made with Concord grapes contains the highest and broadest range of polyphenols as well as having the highest antioxidant capacity, equal to those found in a Beaujolais red wine.
Alan Crozier, Professor of Plant Biochemistry and Human Nutrition, said: "Not all fruit juices are the same.
"Supplementing a healthy diet with a regular intake of a variety of fruit juices such as purple grape juice, grapefruit juice, cloudy apple juice and cranberry juice, will, without major dietary changes, increase the consumer's intake of phenolic antioxidants.
"Dietary polyphenols through their antioxidant properties, and possibly other mechanisms, are believed to play a role in protecting against chronic diseases."
The study will be featured in the Journal of Agricultural and Food Chemistry.