Sugary drinks - including fruit juice and fizzy pop - may increase the risk of cancer, French scientists say.
The link was suggested by a study, published in the British Medical Journal, that followed more than 100,000 people for five years.
The team at Université Sorbonne Paris Cité speculate that the impact of blood sugar levels may be to blame.
However, the research is far from definitive proof and experts have called for more research.
What counts as a sugary drink?
The researchers defined it as a drink with more than 5% sugar.
That included fruit juice (even with no added sugar), soft drinks, sweetened milkshakes, energy drinks and tea or coffee with sugar stirred in.
The team also looked at diet drinks using zero-calorie artificial sweeteners instead of sugar but found no link with cancer.
How big is the cancer risk?
The study concluded that drinking an extra 100ml of sugary drinks a day - about two cans a week - would increase the risk of developing cancer by 18%.
For every 1,000 people in the study, there were 22 cancers.
So, if they all drank an extra 100ml a day, it would result in four more cancers - taking the total to 26 per 1,000 per five years, according to the researchers.
"However, this assumes that there is a genuine causal link between sugary drink intake and developing cancer and this still needs further research," said Dr Graham Wheeler, statistician University College London.
Of the 2,193 cancers found during the study, 693 were breast cancers, 291 were prostate cancers and 166 were colorectal cancers.