A super-strength chewing gum is allowing people to smell and taste again after they lose their senses.
The University of Nottingham has designed an intensely flavoured gum that acts like physiotherapy for sensory nerves, encouraging regrowth and repairing brain connections.
Trial participants who had not smelt for three years were able to recognise aromas and tastes after only six weeks of daily chewing.
The invention recalls the gum devised by Willy Wonka in Charlie and the Chocolate Factory, by Roald Dahl, which tasted like a three-course meal, including blueberry pie for dessert. But testing of the fictional concoction was not complete, and when the character of Violet Beauregarde snatched a piece, she blew up like a blueberry.
Dr Paul Wicks, a neuropsychologist from the University of Nottingham who took part in the pilot trial after losing his sense of smell, said: "The first time flavour punched me in the face was a blueberry.
"I had blueberries on my cereal most mornings for the preceding year, and I just had them for nutrient content, and one day I put one in my mouth, and the entire world turned purpley blue. I felt like Violet Beauregarde."
He added: "About a week later, I ran the lawn mower over a hidden dog poo on the grass. It was like being hit by a garbage truck.
"Every time I fill up my coffee machine, it's the highlight of my week, because I get to smell the beans. I smell the kids' hair at every opportunity."
It is thought around 3.5 million people in Britain – around 5 per cent of the population – have problems with smelling, which also stops them being able to taste properly.
Not only does it spoil their enjoyment of eating, but it can have serious health implications, because they are unable to smell gas leaks, fires or notice that food has gone off.
The loss of smell because of aging is also linked to frailty in older adults, whose nutrition suffers because food is less attractive, experts believe.
People can lose their smell for a number of other reasons, including viral infections, head injuries and certain medications, such as chemotherapy.
To address the problem, Dr Nicole Yang, of Nottingham University, developed the extra-strong chewing gum to prompt the brain into restoring lost sensory pathways.
Smell retraining using essential oils is a known therapy, but it has limited success.
Dr Yang said: "I started to wonder, can we have a more effective system? Can we make it more engaging? That's how the idea of chewing gum comes to my mind.
"Chewing can stimulate multi-sensory perception, sweetness, sourness and all the flavour that's embedded there, and so I thought this could be a powerful way for us to stimulate multiple sensations."
The Nottingham team looked for suitable chewing gums on the market but found none of them had the strong flavours needed to stimulate the sense organs sufficiently. So they developed their own with multilayered flavours, and sensations of hot and cool.
In a small pilot study involving 16 people, 67 per cent reported an improved sense of smell and 83 per cent reported improved taste.
Dr Yang added: "People are worried when they lose their sense of smell. They fear they may smell, because they can't sense their body odour, and worry that they can't smell bad milk, or gas."
"When we followed up after the training the results were encouraging. People said they could smell more in their daily life, they said, 'I can smell perfume, and smells on the street."
"Some people said, 'I tend to detect coconut. I can smell things like coffee, onions and roses."
"So it's a very simple intervention and we think that, once the brain has been retrained, it will stay that way."
She added: "I know we can't draw conclusions only with a small cohort that completed the study, but the results are clear and visible that this training has a positive influence on smell and taste."
The team is now hoping to test the chewing gum in larger trials.