The federal government's decision to update food labels last month marked a sea change for consumers: For the first time, beginning in 2018, nutrition labels will be required to list a breakdown of both the total sugars and the added sugars in packaged foods. But is sugar really that bad for you? And is the sugar added to foods really more harmful than the sugars found naturally in foods?
We spoke with some top scientists who study sugar and its effects on metabolic health to help answer some common questions about sugar. Here's what they had to say.
Why are food labels being revised?
The shift came after years of urging by many nutrition experts, who say that excess sugar is a primary cause of obesity and heart disease, the leading killer of Americans. Many in the food industry opposed the emphasis on added sugars, arguing that the focus should be on calories rather than sugar. They say that highlighting added sugar on labels is unscientific, and that the sugar that occurs naturally in foods like fruits and vegetables is essentially no different than the sugar commonly added to packaged foods. But scientists say it is not that simple.
So, is added sugar different from the naturally occurring sugar in food?
It depends. Most sugars are essentially combinations of two molecules, glucose and fructose, in different ratios. The sugar in a fresh apple, for instance, is generally the same as the table sugar that might be added to homemade apple pie. Both are known technically as sucrose, and they are broken down in the intestine into glucose and fructose. Glucose can be metabolised by any cell in the body. But fructose is handled almost exclusively by the liver.
"Once you get to that point, the liver doesn't know whether it came from fruit or not," said Kimber Stanhope, a researcher at the University of California, Davis, who studies the effects of sugar on health. Stanhope noted that while the liver may not know whether the fructose came from an apple or a soft drink, the way the liver processes that fructose could possibly be affected by some of the beneficial components in fruit. In contrast to soda, fruit contains fibre, vitamins, minerals and numerous other bioactive components. "We don't know if and how these components may counteract the negative effects of fructose overload in the liver," she said.
The type of sugar that is often added to processed foods is high-fructose corn syrup, which is the food industry's favoured sweetener for everything from soft drinks to breads, sauces, snacks and salad dressings. Made commercially from cornstarch, high-fructose corn syrup is generally much cheaper than regular sugar. It contains the same components as table sugar - glucose and fructose - but in slightly different proportions.
What about "natural" sweeteners?
Food companies like to market agave nectar, beet sugar, evaporated cane juice and many other "natural" sweeteners as healthier alternatives to high-fructose corn syrup. But whatever their source, they are all very similar. To suggest one is healthier than another is a stretch, experts say. In fact, last month, the Food and Drug Administration (FDA) urged food companies to stop using the term evaporated cane juice because it is "false or misleading" and "does not reveal that the ingredient's basic nature and characterising properties are those of a sugar."
Is high-fructose corn syrup worse than regular sugar? How is it different?
High-fructose corn syrup and regular sugar are so similar that most experts say their effects on the body are essentially the same.
The main difference is that the variety of high-fructose corn syrup used in soft drinks tends to have more fructose. In one 2014 study, researchers analysed more than a dozen popular soft drinks and found that many sweetened with high-fructose corn syrup - including Pepsi, Sprite, Mountain Dew, Coca-Cola and Arizona Iced Tea -contained roughly 40 per cent glucose and 60 per cent fructose. Regular sugar contains equal parts glucose and fructose.
Why doesn't the FDA require that added sugars be listed in teaspoons rather than grams?
When the new food labels go into effect, the daily recommended limit for added sugars will be 50 grams, or roughly 12 teaspoons, daily. (One teaspoon of sugar is 4.2 grams.) But the new food labels will list the amount of added sugars solely in grams.
Many nutrition advocates have urged the FDA to require that food labels list added sugars in both teaspoons and grams on food labels, arguing Americans often underestimate the actual amount of sugar in a product when it's expressed in grams alone. But the FDA sided with the food industry, which opposed the teaspoon proposal.
"It would be difficult, if not impossible, for a manufacturer to determine the volume contribution that each ingredient provides toward the added sugars declaration," the agency said. "For example, a cookie made with white chocolate chips and dried fruit would have added sugars in the form of sugar in the batter as well as in the white chocolate chips and the dried fruit." The FDA also said that requiring both grams and teaspoons would "cause clutter and make the labels more difficult to read."
So what's the issue with added sugars?
It mainly comes down to the way they're packaged. Naturally occurring sugar is almost always found in foods that contain fibre, which slows the rate at which the sugar is digested and absorbed. (One exception to that rule is honey, which has no fibre.) Fibre also limits the amount of sugar you can consume in one sitting.
Why is it a problem to have too much sugar?
Many nutrition experts say that sugar in moderation is fine for most people. But in excess it can lead to metabolic problems beyond its effects on weight gain. The reason, studies suggest, is fructose. Any fructose you eat is sent straight to your liver, which specialises in turning it into droplets of fat called triglycerides.
©2016 The New York Times News Service
