Just one fizzy drink a day could leave middle-aged people at risk of a heart attack or stroke, research suggests.
Scientists from Tufts University in Massachusetts followed more than 59,000 people for around 12 years.
While the participants started with healthy levels of “good” cholesterol, those who treated themselves to a soda, energy drink or fruity punch every day saw it “move in the wrong direction”.
The daily indulgence increased their risk of low amounts of good cholesterol, which removes “bad” forms from the bloodstream, by 98%.
It also raised their risk of dyslipidemia, abnormal lipids in the blood, by 53%.
Both of these have been linked to greater odds of heart disease.
“The results suggest high intake of drinks with added sugar, such as soda, lemonade or fruit punch, may influence risk for dyslipidemia as we age,” said study author Professor Nicola McKeown.
“One dietary strategy to help maintain healthier blood cholesterol and triglyceride levels may be to avoid drinks with added sugars.”
Heart disease is a leading cause of death, killing one in four people in the UK and US.
With obesity a known trigger, many have pointed the finger at sugary drinks.
To learn more, the scientists looked at thousands of middle-aged or older adults who took part in the Framingham Heart Study.
The participants reported their drink consumption, with their cholesterol and triglyceride levels being measured every four years.
Compared to those who “rarely” indulged in the sugary drinks, those who did so daily were 98% more likely to have low levels of good cholesterol and 53% more at risk of raised triglycerides - fat in the blood.
This remained true after BMI, overall diet, activity levels and alcohol intake were accounted for.
While age is a risk factor for heart disease, the results also seemed to apply to the participants in their forties.
“With these younger participants, we did see unfavourable changes, but they were likely too young during the short follow-up period to know if they would eventually develop dyslipidemia,” said study author Dr Danielle Haslam.
“Our findings contribute to the mounting evidence that sugary drinks should be avoided to help maintain long-term health.”
Diet drinks and 100% fruit juices were not linked to the heart disease risk factors.
Nevertheless, the scientists recommend people enjoy them in moderation.
“We are better off quenching our thirst with water,” said Professor McKeown.
“The emerging research on long-term consumption of diet soda on health is inconclusive, so it's prudent to say diet drinks should only be an occasional indulgence.
“As for 100% fruit juice, best to limit consumption and consume whole fruits when possible”.
Sugary drinks were not linked to raised levels of “bad” cholesterol, which can build-up in arteries.
Statistics show heart disease deaths are on the rise in young people.
In 2017, 42,384 people under 75 died from the condition, up from 41,042 in 2014.
The British Heart Foundation warns progress in preventing these fatalities has “slowed to a near standstill”.