Cancer incidence is set to increase by 70% globally between now and 2024, according to the World Health Organisation's World Cancer Report published earlier this month. The report states that much of the increase will be down to lifestyle factors – not just smoking, but also physical inactivity and excessive consumption of sugar (leading to obesity) and alcohol.

Changing people's behaviour is notoriously difficult and costly, but what if it were possible to greatly reduce the toxic effect of one of these lifestyle choices, alcohol? This is what David Nutt, professor of neuropsychopharmacology at Imperial College London and former chairman of the UK government's Advisory Council on the Misuse of Drugs hopes to achieve with an alcohol substitute he is working on. The drug would be intoxicating but harmless.

I spoke to Nutt last week about the genesis of his alcohol substitute. "I have spent 20 years trying to reduce the harms of alcohol, and then about 10 years ago – while working under the UK's Foresight initiative – we thought 'we'll never stop alcohol being toxic because it's intrinsically such. It causes cancer or liver disease, for example. So why don't we replace it with a safe drug?'"

His proposed alternative to alcohol works by targeting the same receptors as the neurotransmitter gamma aminobutyric acid, or Gaba, which has a "relaxing" effect on the central nervous system. These receptors are the target of several widely used drugs, including barbiturates, benzodiazepines (such as Valium) – and alcohol.

Nutt's alcohol substitute is a benzodiazepine derivative, but he is adamant that what he is offering is more than just another form of Valium. It targets the same sites in the brain, but he believes the drug will not cause the same problems with addiction and withdrawal. "Modern science allows us to target the relaxing and intoxicating part, while avoiding the bad parts like addiction and withdrawal," he said.

The drug is already used in humans for other indications, he adds. "Addiction is a complex process. I am confident that the physically addictive properties of this drug are minimal, and that it is much less addictive than alcohol. More work will be required before I can conclusively demonstrate this, however."

For commercial reasons, he is not prepared to reveal the drug's identity for the time being. But in its current form, it has some important limitations. In particular, it cannot be used in beer or wine because if affects their flavour, and tweaking the drug's chemistry to make it more palatable will require "more funding, more chemistry muscle", acknowledges Nutt.

In the meantime, he plans to offer it in the form of a non-alcoholic cocktail. The intoxicating effect of the first three "doses" will be cumulative, he said, but subsequent shots will have no effect. Remarkably, he has also created an antidote, or "sober-up pill".

I asked him what market he had in mind for his alcohol substitute. Who would buy it?

"I want it to be sold in high-quality cocktail bars where people go and re-learn about the pleasures of drinking in a social environment with friends, drinking sensible amounts," he said. "Maybe it could be sold alongside alcohol, so that people could see the difference between it and those drinking alcohol and getting into fights.

"It will be an upmarket product for people who want to drink responsibly. You can never do that with alcohol because it turns off the parts of the brain that create responsibility."

Nutt admitted that people are often sceptical when they hear about his work, but he believes the harms of alcohol demand radical alternatives.

"Alcohol is the leading cause of death in Britain today in men between the ages of 16 and 50," he said. "It has overtaken traffic accidents, suicide and cancer. The health costs amount to £3bn a year. Most people say, 'my God, what a clever idea, but it could never work. How are you going to license it? Is it going to be a legal high?'

"At one level they're right," said Nutt. "Alcohol is a drug that has been around for thousands of years, and western society is immersed in it, so this will be quite a revolution."

The reaction of drinks companies thus far has ranged from confused to sympathetic. One of the world's biggest, Diageo, was sceptical.

"Diageo does not believe a synthetic form of alcohol that reduces or eliminates the harmful effects of excessive use is on the horizon," a spokesperson for the company told me. "Based on our understanding, Dr Nutt is seeking to create a derivative of benzodiazepine. Our company has some of the world's most iconic brands, many with hundreds of years of tradition and craft. Consumers around the world enjoy our brands responsibly and we believe they are looking for the craft and taste associated with our brands and will continue to do so."

Sarah Williams, health information officer with Cancer Research UK, was less dismissive, describing the alcohol substitute as "an interesting idea", noting that "the less alcohol a person drinks, the lower their risk of cancer". But she said more research into Nutt's drug would be needed.

"We're keen to see how the research develops, particularly to check that it doesn't cause a different set of health risks. But it's important that this doesn't distract policymakers from other evidence-based ways to protect public health by reducing alcohol consumption in the UK, such as minimum unit pricing."

Prof Nutt is adamant that the drug is safe, and that just as the tobacco industry eventually came to accept the worth of electronic cigarettes, the alcohol industry will come to accept that an alcohol substitute has a place.

He is currently working with Imperial Innovations, a technology commercialisation company that collaborates with four of the UK's leading universities, to bring the drug to market. With sufficient funding, he thinks this could happen as soon as next year.

"I know the product is safe. And the drinks companies know that their product kills [almost] three million people a year. They would like a safer alcohol, but the market is growing in Asia and Africa. That's why we need to incentivise them to change. What we need is for the public to say 'we need this', and for governments to encourage it as a health substitute."