Eating too much sugar in foods such as soft drinks, cakes and cereals will not just pack on the pounds, it can increase the risk of dying of heart disease.
New research published on Monday in the journal JAMA Internal Medicine shows that people who get 25 per cent or more of their daily calories from added sugar almost triple their risk of dying of heart disease.
Even those who have more moderate levels of sugar consumption, from 10 to 25 per cent of their daily diet, still increase their cardiovascular risk by 30 per cent.
In the U.S., the Institute of Medicine recommends that people not consume more than 25 per cent of their daily calories in added sugars, while the World Health Organization sets the threshold at 10 per cent. However, Canada does not have guidelines on safe levels of sugar consumption, as it does with salt and trans fats.
While excessive sugar consumption has long been considered a health risk, a paradigm shift in thinking now holds that sugar not only contributes to conditions like obesity and diabetes, it damages the body's organs directly.
"Too much sugar does not just make us fat; it can also make us sick," said Laura Schmidt, a researcher at the Philip R. Lee Institute for Health Policy Studies at the University of California San Francisco.
The research should spark a serious discussion of how much sugar is safe, Ms. Schmidt added.
Overall, Americans consume 15.5 per cent of calories from added sugars; in Canada, the figure is 10.7 per cent.
But there is a wide range: About 10 per cent of adults consume 25 per cent or more of their calories from added sugar; another 72 per cent consume between 10 and 25 per cent in the form of sugar; the balance, 18 per cent, have a diet that consists of less than 10 per cent of calories from sugar.
The new research, led by Quanhe Yang, a researcher in the office of public health genomics at the U.S. Centers for Disease Control and Prevention, suggests those levels are too high.
"The risk of CVD [cardiovascular disease] mortality increased exponentially with increasing the usual percentage of calories from added sugar," Dr. Yang wrote.
Views range broadly on safe levels of sugar consumption, and the issue is highly controversial with industry and regulators.
The American Heart Association is far more concerned about the dangers of excess sugar; it recommends that women get no more than five per cent of their daily calories from that source, and men not exceed 7.5 per cent.
The Heart and Stroke Foundation of Canada does not have specific guidelines on sugar consumption. Rather, it encourages Canadians to follow Canada's Food Guide for Healthy Eating, which includes a vague recommendation that Canadians limit excess fat, sugar and salt.
But the Canadian Sugar Institute said the scientific consensus is that "there is no evidence of harm attributed to current sugar consumption levels. Dietary advice must be based on the totality of evidence, not single studies suggesting an association between individual dietary factors and disease."
The research was conducted using data from the National Health and Nutrition Examination Survey (NHANES), which was conducted in stages between 1988 and 2010; the long-running research project collects detailed nutritional information and tracks mortality. Data from more than 43,000 people were included in this analysis.
Researchers focused on consumption of added sugars, a category that includes all sugar, corn syrups, honey, and maple syrup added to foods. It does not include sugars that naturally occur in fruits, vegetables and dairy products.
The main sources of added sugars, according to the CDC study, are sugar sweetened beverages like soft drinks and sports drinks, 37 per cent; deserts like cakes and puddings, 14 per cent; fruit drinks, nine per cent; dairy desserts, six per cent; candy, six per cent.
Dr. Yang and the research team found that a person who drinks an average of one sugar sweetened beverage daily has a 29 per cent higher risk of dying of heart disease than a person who drinks just one a week.
A single can of soda pop like Coke contains 35 grams of sugar and 140 calories.
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André Picard