Centre for Disease Control (US) – analysis of data from research data (US data from the National Health ans Nutrition Examination Survey.)
Researchers from the CDC looked at data from 31,000 people who’d taken part in the National Health and Nutrition Examination Survey, comparing a multitude of different lifestyle and physical variables to health outcomes.
The good news is that sugar consumption has decreased in the US a bit over the years. The percentage of calories they get from added sugar decreased from 16.8% in 1999-2004 to 14.9% in the years 2005-2010.
The slightly discouraging news is that 70% of adults consumed 10% or more of their daily calories from added sugar – and about 10% of adults consumed more than 25% of their calories from added sugar.
The bad news is that added sugar appears to significantly increase our risk of death from heart disease. People who consumed about 15% of their daily calories from added sugar had a 18% higher risk of dying from heart disease, compared to people who only took in very little added sugar. For people whose added sugar intake made up over 21% of their daily calories, their risk of death doubled.
And the phenomenon appears to be completely independent of other factors – like weight, calories consumed, smoking, blood pressure, sex, cholesterol level, and physical activity – which indicates that there’s something specific about the relationship between sugar and the heart.
What could sugar be doing to increase the risk of heart disease? There are a lot of possibilities. One is that sugar has been shown to increase blood pressure, independent of other health problems it can trigger. Another idea is that it increases unhealthy blood fats like triglycerides and “bad” LDL cholesterol levels, while decreasing “good” HDL cholesterol. Other studies have suggested that excess sugar can trigger inflammation in the body, by boosting levels of certain inflammatory biomarkers. Finally, some studies have suggested that sugar may enhance the genetic effects of obesity, boosting the heart risks that obesity genes were already threatening to begin with.
“Our findings indicate that most US adults consume more added sugar than is recommended for a healthy diet,” the authors write. “A higher percentage of calories from added sugar is associated with significantly increased risk of CVD mortality.”
The bottom line is that added sugar appears to confer risks far beyond weight gain. In her editorial, Laura Schmidt, a UCSF researcher, says that we’re beginning a paradigm shift in the current thinking on sugar. Unlike trans fats and salt, she points out, there’s no upper limit to how much food companies can add: Sugar is on the FDA’s (Federal Drug Administration) “generally recognised as safe” list. This, she suggests, should change.
The WHO (World Health Organisation) recommends having added sugar make up no more than 10% of our daily calories, while the Institute of Medicine (IOM), a U.S. organization, is more lenient, saying upper limit should be 25%. But the American Heart Association is much more conservative, recommending that added sugars should be limited to 100 calories per day for women and 150 per day for men.
The new study supports that this lower estimate is probably pretty smart. As Schmidt says, one thing’s for sure: “Too much sugar does not just make us fat; it can also make us sick.”