It 'unleashes the medical benefits of cacao,' said developers Kuka Xoco

Company created prototype bar which has just 35 per cent sugar and fat

For those of us who love nibbling on chocolate but feel guilty afterwards, this could be the news we've been waiting for.

Scientists claim they have developed a type that is so healthy it could be taken as medicine.

The key ingredient in chocolate, cacao, contains antioxidants and minerals, and can even help lower blood pressure while increasing 'good' cholesterol.

But these health benefits are outweighed by the fact most chocolate bars are at least 70 per cent fat and sugar.

Miracle cure: Scientists claim they have developed a type of chocolate (file photo) that is so healthy it could be taken as medicine

Now, an American company has developed a prototype that is only 35 per cent sugar and fat, by sweetening the unpalatable pure cacao with a herb from the Andean region of Bolivia and Peru.

Gregory Aharonian of Kuka Xoco, which is developing the chocolate, said: 'Using micrograms of coca plant extract, we can de-bitter unsweetened cacao.

'This eliminates the need for sugar, sweeteners and much of the fat in chocolate, unleashing the medical benefits of cacao.'

He added that their long-term goal was to develop chocolate that was just ten per cent fat and sugar.

The firm, which is based in Boston in the US and in Bolivia, argues that artificial sweeteners have failed because they taste bad, lead to weight gain and have adverse health effects. Its product is due to go on sale next year.

Health benefits: An American company has developed a prototype that is only 35 per cent sugar and fat, by sweetening the unpalatable pure cacao - the key ingredient in chocolate (file photo)

Speaking at the World Chocolate Forum in London this week, Mr Aharonian described sugar as 'the next nicotine' and argued that if the unhealthy ingredients were removed from chocolate, it could and should be eaten medicinally.

He said: 'In America, the $100billion-a-year chocolate industry could become a $200billion-a-year health food industry, if only much of the sugar and fat could be removed.