The producer of An Inconvenient Truth, a documentary that fundamentally changed the way many people look at climate change, has set her eyes on a new, equally ambitious target: sugar. The new film, called Fed Up, opens in theatres next week, and is an exposé of the deadly consequences of excessive sugar consumption that accuses governments and the food industry of failing to combat the problem.
For decades, many believed the only damage sugar caused was tooth decay and weight gain. But in recent years, the case against it has been building with fantastic speed, and now a growing chorus of physicians and scientists believe the dangers are comparable to those of smoking.
Study after study shows that even moderate amounts of sugar can increase the risk of diabetes, heart disease, stroke and premature death.
In February, researchers reported in the Journal of the American Medical Association that people who get 10 to 25 per cent of their daily calories from sugar increase their risk of cardiovascular problems by 30 per cent.
The concern is so great that in March the World Health Organization said people should aim to limit their consumption of added sugar to 5 per cent of their caloric intake, which is about 100 calories for the average adult.
It's not the sugar found in fruit or milk that has scientists and health advocates so worried. It's the sugar that is added to cereal, condiments and sauces, packaged bread and drinks.
"Much of the sugar is hidden in our food supply, in various beverages," says Dr. Frank Hu, professor of nutrition and epidemiology at the Harvard School of Public Health and one of the authors of February's JAMA study. "It's not really necessary to add too much sugar to these foods."
But it turns out that most Canadians don't actually know what "sugar" refers to – or that a large proportion of the sweetener that is added to the food supply is, in fact, a substance that many experts believe is even more toxic: high fructose corn syrup.
HFCS is the primary ingredient in soft drinks and can be found in everything from granola bars, canned pasta and chocolate milk to barbecue sauce and frozen desserts. Because of widespread campaigns based in the U.S., many Canadians are aware that there are concerns over its safety. But in Canada, it has a different name: "glucose-fructose" or "sugar/glucose-fructose," which causes many label readers to mistake it for regular sugar. A 2011 industry survey found that only a quarter of respondents knew the difference.
The distinction goes far beyond semantics. Many health experts in the field say that sugar is bad, but HFCS is much worse. It appears to wreak havoc on the body, causing fat to be stored in the liver, where it can cause scarring and permanent damage. It can lead to excessive abdominal weight gain, which is a major risk factor for heart disease. Studies show it causes high levels of triglycerides to be released into the blood, another cardiovascular risk factor.
Health experts say the federal government should change labelling rules to make the inclusion of HFCS transparent, arguing that, if more Canadians knew how ubiquitous the sweetener is, as well as the consequences increasingly linked to it, they would think twice about what they eat and drink.
"All sugars aren't the same," says Dr. Anil Nigam, director of the research program in preventive cardiology at the Montreal Heart Institute. "Bottom line: people are eating too much sugar and the sugar they're eating is probably the worst kind."
The use of HFCS began in earnest in the 1970s, when sugar prices rose dramatically. Corn was in abundant supply in the U.S., so its syrup, which could be processed into the even sweeter HFCS, offered a much cheaper alternative.
Soon it became the primary ingredient in items throughout the grocery store. U.S. subsidies to corn farmers continue to sustain the cost advantage.
Like the sucrose extracted from sugar cane or beets, HFCS consists of glucose and fructose molecules, which the food industry argues makes it perfectly safe. But there is mounting evidence to suggest otherwise. Unlike sucrose, the glucose and fructose are not bonded in HFCS – which many researchers believe makes a vital difference to the way our bodies react to it.
In 2010, researchers at Princeton University published a study in which rats fed on a menu that included HFCS gained substantially more weight than those whose diet did not. They also were more inclined to develop metabolic syndrome, a group of conditions including high blood pressure and excessive abdominal fat, both of which are precursors to heart disease, stroke and other serious health issues.
A 2011 study published in the Journal of Clinical Endocrinology and Metabolism found that people who drank beverages sweetened with HFCS had higher levels of triglycerides, which also can lead to heart disease.
Many experts believe that HFCS causes problems because the uncoupled fructose is absorbed by the liver and converted into fat that can damage the liver, and lead to cirrhosis and finally organ failure.
As well, some fat globules can be released into the bloodstream, a risk factor for heart disease. Even if individuals aren't considered overweight, there is evidence that suggests HFCS could be doing internal damage.
Fructose also fails to trigger the release of insulin and leptin, which alert the body when someone has eaten enough. This can promote weight gain that leads, in turn, to obesity, metabolic syndrome, diabetes, heart disease and stroke.
It is difficult to get a clear picture of how much HFCS – or even plain sugar – that Canadians consume. A decade old, Statistics Canada's most recent figures show that over-all levels of daily added sugar consumption hovered around 10 per cent of total daily calories, the level that the WHO still recommends officially. (The agency says that limiting added sugar to 5 per cent of daily calories is ideal, but difficult for consumers to achieve, given how much is added to food.)
Look deeper, though, and it's apparent that among certain age groups – notably the young – sugar intake is much higher. And the cause seems clear: A Statscan report in 2011 found soft drinks to be the number one source of added sugar in the diet of those between 9 and 18, and the second biggest source for people 19 and older. The vast majority of soft drinks are sweetened with HFCS.
Over all, more than one-third of the sugars that Canadians consume (almost half for teenage boys) is added to products by food companies – and the impact may be long-term.
Laura Schmidt, a specialist in health policy at the University of California at San Francisco, argues that continued consumption of HFCS causes children to develop chronic diseases at younger ages and suffer throughout their lives.
"We're talking about really raising a whole cohort of kids that … will live with chronic disease," she says.
For almost every study linking HFCS to illness, however, there is another report – often from research supported by food companies or corn growers – that disputes the claim.
Stephanie Baxter, representing the Canadian Beverage Association, says that not only does the evidence show HFCS to be safe, sweetened beverages are not to blame for the rising rates of obesity.
"It's the over-consumption of calories as a whole," Ms. Baxter contends.
But researchers like Dr. Nigam dismiss such arguments as outdated and certain to be debunked as even more robust evidence emerges.
"If you look, calorie for calorie, they're not the same," he says, adding that many Canadians won't realize this until food labelling reflects the true nature of the role HFCS plays in their diets.
Perhaps surprisingly, sugar producers are among those keen to see food labels changed. They want to distance themselves from the increasingly negative publicity generated by HFCS. A survey conducted by the Canadian Sugar Institute found that nearly 90 per cent of respondents would like to see sugar and HFCS listed as separate ingredients.
But that is hardly ideal for consumers, argues Richard Johnson, a professor of medicine at the University of Colorado Denver. He says that quibbling over which is worse is like trying to decide whether cigars do more harm than cigarettes. It also misses the point: that people are simply consuming far too much sweet stuff.
Tom Warshawski, chair of the Childhood Obesity Foundation, agrees, saying that providing Canadians with a true understanding of how much sugar is being added to their diet – and putting lives at risk – requires the co-operation both of government and the food industry.
"It takes a long time to accumulate the data to show the link between exposure and disease," Dr. Warshawski explains.
"Now the information is catching up with people's intuition, and it has become quite clear that sugar, and the amounts consumed by the average Canadian, is toxic."
A little guidance
The Canada Food Guide warns against beverages with added sweetness, but many experts feel the government should draft specific guidelines to help consumers manage their sugar intake.
Health Minister Rona Ambrose has been largely silent on the subject. However, in November, 2010, her department (then under predecessor Leona Aglukkaq) launched a campaign geared to children that featured televised advertisements connecting sugary drinks with obesity.
Four months later, the commercials abruptly disappeared from the airwaves, and now can't be found even online.
Department spokesman Gary Holub says the campaign simply ran its course. Coincidentally, it ended not long after Coca-Cola informed the government that it planned to lobby Health Canada on food guidelines.
At the time, the company said it wanted to "ensure appropriate scientific approach to promotion of healthy and active lifestyles."
Asked this week to clarify that goal, Coke representative David Moran replied via email that the language "does not reflect the company's position and will be changed asap." He also pointed out that Coca-Cola offers many low- and no-calorie beverage options, and works to promote healthy living.
It also continues to counsel the government on nutrition, meeting with Dr. David Butler-Jones, the country's chief public health officer, in February, 2012, and last October with a group that included the department's policy director as well as high-profile MP Eve Adams, who had been appointed parliamentary secretary to Ms. Ambrose the previous month.
Sugar is far from the only sign of sweetness on a product's label. Here are some others:
Evaporated cane juice
High-fructose corn syrup
Source: Harvard School of Public Health