A fruit basket may be the perfect Christmas or birthday gift for somebody who has food allergies or a weak immune system.

Fruits and green vegetables are alkaline and they will help to prevent a person's immune system reacting in an allergic manner to a range of foods that they have not previously been allergic to, said Alison Wyndham, who has founded her own pain relief clinics in London and Hertfordshire.

She explained that pollutants in the environment become absorbed by the body and are processed in the liver to be stored as fatty tissue. Once they are metabolised they produce a "chronic" strain on the nervous system and make it react in unfamiliar ways – such as allergic reactions.

Fruit baskets could also help people increase the amount of fibre they get in their diets.

Sian Porter, spokeswoman for the British Dietetic Association, said eating the whole fruit was much healthier than relying on fruit juices to make up the recommended five a day.