Drinking two glasses of fruit juice a day may increase the risk of cancer by more than 50 per cent, a major study has found.

The analysis of more than 100,000 adults revealed particularly strong correlations between the sugary soft drink and breast cancer.

While recent public health campaigns have focused largely on the risks from fizzy drinks, the new findings, published in the BMJ, provide arguably the strongest evidence yet that fruit juices - also high in sugar - are comparably dangerous.

Fruit juices count as one of a person’s recommended five portions of fruit and vegetables a day, according to NHS advice.

They are currently exempt from the so-called sugar tax, which came into force last year.

The French study enrolled 101,257 healthy adults with an average age of 42, analysing their dietary habits and recording any instances of cancer for up to nine years.

Scientists looked for correlations between various forms of cancer and consumption of fruit juice, traditional fizzy drinks and artificially sweetened or “diet” fizzy drinks.

They found that a 100ml of fruit juice was linked to a 12 per cent increased risk from cancer overall, and a 15 per cent increased risk of breast cancer.