Researchers from the University of Minnesota, led by Noel Mueller, studied the intake of soft drinks and fruit juice by 60,524 participants from Singapore over 14 years.

During the time of the study, 140 people developed pancreatic cancer.

The researchers calculated that drinking just two sweet, carbonated drinks a week increased individuals of developing pancreatic cancer by 87 per cent.

However, the study found no link between juice consumption and pancreatic cancer.

What causes the raised risk?
Dr Mueller believes that the high sugar content of many soft drinks may increase insulin production and promote the development of pancreatic cancer.

Chronically elevated blood glucose reduces insulin sensitivity, leading to hyperinsulinemia and increased blood circulation and cell division within the pancreas.

Exposure to higher insulin levels may also activate signalling pathways involved in the development of pancreatic cancer.

The researchers suggest that high fruit juice intake may not be associated with an increased pancreatic cancer risk because of differences in the composition of fruit juice and other soft drinks.

They also suggest that people who drink fruit juice may have generally healthier lifestyles.

But they said it was difficult to separate the influence of soft drinks from other unhealthy lifestyle habits.

How significant is this finding?
Cancer Research UK said that differences between the lifestyles of the participants who drank large quantities of fizzy drinks and those who did not may play an important role in the study's findings.

Those who drank lots of fizzy drinks were more likely to be unhealthy in other ways, including smoking, eating more calories and being less active, the charity pointed out.

'It is difficult to separate the effects of all of these things,' said Jessica Harris, health information officer at Cancer Research UK.

'Although this study included a lot of people, very few of them developed pancreatic cancer so it is difficult to know if soft drinks do increase the risk of pancreatic cancer, or whether the results are just down to chance,' she said.

Cancer Research UK considers evidence in this area to be 'still inconsistent', since previous studies have failed to find any such link, she said.

But, she added, it is important to remember that fizzy drinks can contribute to obesity, which in turn increases the risk of many forms of cancer.

• Cancer Epidemiol Biomarkers Prev; 19(2); 447-55.

Informing patients
There may be a link between high fizzy drink intake and pancreatic cancer, but studies do not produce a consensus. There was no link between juice consumption and pancreatic cancer. Drinking fizzy drinks can contribute to obesity, a known risk factor for many types of cancer.