Consuming too many sugary sweets, desserts and drinks can triple your chances of dying from heart disease.
Scientists in the US have found a striking association between the proportion of daily calories supplied by sugar-laden foods and heart disease death rates.
One sugar-sweetened beverage a day is enough to increase the risk of dying from cardiovascular disease (CVD) affecting the heart and arteries.
For people obtaining a quarter of their calories from added sugar, the risk tripled compared with those whose sugar contribution was less than 10 per cent.
Sugar consumption in the top fifth of the range studied doubled the likelihood of death from heart disease.
The researchers specifically focused on added sugar in the diet - that is, sugar added in the processing or preparing of food, rather than natural sources.
Dietary guidelines from the World Health Organisation recommend that added sugar should make up less than 10 per cent of total calorie intake.
Yet many processed foods and beverages are packed with sugar. A single can of fizzy drink, for instance, may contain 35 grams of sugar providing 140 calories.
The new study, led by Dr Quanhe Yang, from the Centres for Disease Control and Prevention in Atlanta, used US national health survey data to determine how much added sugar people were consuming.
Writing in the journal JAMA Internal Medicine, the authors concluded: "Our findings indicate that most US adults consume more added sugar than is recommended for a healthy diet.
"A higher percentage of calories from added sugar is associated with significantly increased risk of CVD mortality."
Professor Naveed Satta, from the British Heart Foundation Glasgow Cardiovascular Research Centre at the University of Glasgow, said: "We have known for years about the dangers of excess saturated fat intake, an observation which led the food industry to replace unhealthy fats with presumed 'healthier' sugars in many food products.
"However, the present study, perhaps more strongly than previous ones, suggests that those whose diet is high in added sugars may also have an increased risk of heart attack. Of course, sugar per se is not harmful - we need it for the body's energy needs - but when consumed in excess it will contribute to weight gain and, in turn, may accelerate heart disease.
"Helping individuals cut not only their excessive fat intake, but also refined sugar intake, could have major health benefits including lessening obesity and heart attacks. The first target, now taken up by an increasing number of countries, is to tax sugar-rich drinks."