We’re all wise to the notion that sugar is a lot worse for us than we thought. Twenty years ago, we were eating fat-free, high-sugar muffins and thought we were being healthy; now we know better. And given the ways in which fructose is metabolized, it seems to bestow even additional health risks over “safer” sugars, like glucose. A new review looks over the evidence to date and lays out the mechanisms by which sugar, and fructose in particular, seems to do its damage. Though the new study is largely a review of previous research, it’s an impressive piece that will, hopefully, urge more people to change even their casual soda habits, and maybe even help shift the status quo is schools, offices, and households to boot.
"Since we rarely consume fructose in isolation, the major source of fructose in the diet comes from fructose-containing sugars, sucrose and high fructose corn syrup, in sugar-sweetened beverages," says Frank Hu, of the Harvard T.H. Chan School of Public Health. "Our findings underscore the urgent need for public health strategies that reduce the consumption of these drinks."
According to the new analysis, one to two servings of sugary drinks per days raises a person’s risk of heart disease by 35%. The same amount raises risk of type 2 diabetes by 25%, and stroke by 15%. It's also been linked to gout, gallstones, and kidney stones.
"Part of the problem is how fructose behaves in the body," said Hu. It does something a little different from other forms of sugar: While glucose is escorted by insulin into cells to be used as fuel, fructose doesn't need the escort. It's processed in the liver, where it can be converted into triglycerides, otherwise known as blood fats. These can lead to insulin resistance, which is a leading cause of not only diabetes, but of heart disease.
Even with all the warnings, people still tend to drink soda for a pick-me-up or guzzle energy drinks like water, which is not good for weight. "This is particularly concerning as the research shows that consuming one or more sugar-sweetened beverages a day has been linked to greater weight gain and obesity in numerous published studies," said Hu. "Regular consumption of sugar-sweetened beverages can lead to weight gain because the liquid calories are not filling, and so people don't reduce their food intake at subsequent meals."
And we don’t just get sugar through drinks – according to the study, after soda and energy drinks, the top sugar-providers are grain-based desserts, fruit drinks, dairy desserts, candy, ready-to-eat cereals, sugars and honey, tea, yeast breads, and syrups and toppings.
The authors call for people to be more cognizant of their sugar intake, of course. But they also like the idea of a sugar tax, front of package label warnings about added sugar, along with changes in policy for drinks in schools and other institutions. It’s important to point out that this new study is mainly a summary of the previous studies on fructose – there’s nothing really novel here, but it is a nice meta-analysis of the existing literature on sugar, and a smart synopsis of the ways in which fructose affects the metabolism. With all the research out there now, including the new study, maybe we'll start to listen. If only they could figure out how to stop it from being so deliciously addictive.
