Fizzy drink a day may double cancer risk

Drinking just one sugary fizzy drink a day could more than double the risk of stomach cancer, research suggests.

Scientists found people who consumed at least one sugar-sweetened drink daily were 2.45 times more likely to develop the disease than those who rarely drank them.

The study tracked 112,284 people over several decades, monitoring their consumption of regular fizzy drinks, punches, lemonades and sports drinks.

Of those taking part, 278 eventually developed stomach cancer, including 140 women and 138 men.

The increased risk was particularly striking among women, who were three times more likely to develop the disease if they drank sugary fizzy drinks every day.

However, people who enjoyed a fizzy drink only a few times a month or week did not appear to face a meaningful increase in risk.

Researchers, writing in Gastro Help Advances, also found higher consumption of fructose, a sugar naturally found in fruit and commonly added to soft drinks, was associated with greater stomach cancer risk.

Artificially sweetened drinks, meanwhile, were not linked to an increased risk of stomach cancer, although scientists cautioned that evidence around artificial sweeteners is still evolving.

The reason sugary drinks might be linked to the disease is also unclear.

Researchers suggested possible explanations could include weight gain, insulin problems, hormonal changes, inflammation or disruption to the bacteria living in the gut.

Stomach cancer is the fourth leading cause of cancer death worldwide, with around 6,800 new cases diagnosed in the UK each year.

Known risk factors include smoking, heavy alcohol consumption and certain stomach conditions, including gastritis and severe acid reflux.

Crucially, the latest study was observational, meaning it can identify an association but cannot prove sugary drinks cause stomach cancer.

The researchers said further work is needed to understand the relationship.