Earlier this year, researchers claimed drinking the juice of the humble root crop can lower blood pressure and might be a simple way of helping to maintain the circulation system.

Since the scientists' findings were splashed in the national media, stockists in Peterborough have reported a surge in demand for the product.

Manager at Notcutts Garden Centre in Oundle Road, Orton Waterville, Nigel Coombs, said sales of bottles of beetroot juice – which costs £2.99 for three-quarters of a litre – had hit 100 a week, outstripping all other organic juices.

Mr Coombs said: "In the last few weeks the sales have gone absolutely bonkers. I think people are becoming more health conscious and have been picking up on the health benefits of it from the press and health magazines, and adding it to their diet.

"As a garden centre, we try to stock natural products which are related to our business, so fruit juices are quite a common thing for us. But this has really taken off."

Beetroot has been prized since Roman times as a treatment for disorders of the blood, as a laxative and as a fever reducer.

The traditional wisdom was given some scientific backing by research led by Professor Amrita Ahluwalia, of the William Harvey Research Institute at St Bartholomew's Hospital, London.

The boffins took 14 healthy volunteers and asked them to drink either half-a-litre of beetroot juice, or the same quantity of water.

Their blood pressure was measured every 15 minutes from one hour before taking the drink until three hours afterwards, with readings at longer intervals subsequently.

Volunteers who drank the juice started to show reductions in both their systolic blood pressure – the pressure as the heart beats – and diastolic or "resting" pressure between beats.

The lowest systolic blood pressure occurred two-and-a-half hours after drinking the juice, and the lowest diastolic pressure three hours afterwards. Systolic pressure was still below starting levels in the juice-takers 24 hours after drinking.

The researchers traced the drop in pressure to nitrate in beetroot, which they said is converted by bacteria in saliva into a chemical which dilates blood vessels.

On the back of their findings, they called for the promotion of a "natural" diet containing vegetables with a high nitrate content.

Mr Coombs said, science aside, he preferred to take his beetroot cooked or in salads rather than as juice.

But he added: "Once people buy it, drink it and find their health benefits, then I am sure it will become a normal thing on their shopping-lists."

Comment: page 12