When Dr. Valerie Tarasuk had minor house repairs done earlier this year, she couldn't help noticing what the two workers discarded at the end of the day.
"After they left, I found a six-pack of energy drinks in the garbage," recalls Tarasuk, a professor of nutrition science at the University of Toronto. "And I just thought, holy cow."
Critics have long assailed the high sugar content and amped-up caffeine doses of some energy drinks, but Tarasuk had another concern. Did the men realize, she wondered, just how large a dose of vitamins they were getting?
Since 2004, when Canada first began allowing the sale of "nutrient-enhanced novel beverages" – Red Bull was the first product available in this new class – the number of these drinks on store shelves has proliferated. Canadians now buy nearly $500-million of energy drinks each year. Amid growing concern about potentially misleading health claims, in 2011 Health Canada implemented new rules about how vitamin-fortified drinks are labelled.
But a new analysis by Tarasuk and her colleagues suggests little has changed since the rules were enacted, and critics argue that packing sugary drinks with vitamins is simply "health-washing." These added vitamins give a healthy veneer to sugary drinks, though they are as likely to hurt well-meaning consumers' health as help it.
Tarasuk and her colleagues analyzed the contents and labelling of 46 different "novel drinks" – a category that includes caffeine-spiked energy drinks as well as vitamin-enhanced waters and juices – from three Toronto supermarkets, publishing the results in the journal Applied Physiology, Nutrition and Metabolism last month. The median number of added nutrients per product was 4.5, and almost every beverage contained at least one nutrient in excess of the daily requirements of young adults.
"It was nothing to find something with two, three, four, in some cases even 12 times the average requirement for an adult male," Tarasuk says. "It makes no sense that you would pick up one bottle of something and it would give you that much B6."
In the past, Canadian law only permitted nutrient fortification to address public-health concerns related to widespread deficiencies, which led to the addition of iodine to salt, folic acid to flour, and vitamin D to milk. The move to "discretionary fortification," long permitted in the United States and Europe, lets manufacturers deploy a whole new range of micronutrients.
In Tarasuk's study, the most commonly added nutrients were vitamins B6, B12, C and niacin. According to Health Canada statistics, virtually no Canadians are deficient in B6, B12 or niacin, while just 13.7 per cent of Canadians could use more vitamin C.
So why bother adding them to your drink? The obvious reason is that they make the drink sound healthier, which is the crux of a class-action launched by the Center for Science in the Public Interest against Coca-Cola's Vitaminwater line in 2009.
"Unfortunately, Coke continues to convince many consumers that Vitaminwater is a healthy alternative to water, when in fact it's much more similar to a can of Coke," says Amanda Howell, the Dallas-based assistant director for litigation at CSPI. Vitaminwater has 120 calories from sugar (the equivalent of eight teaspoons of sugar) in a 591-millilitre bottle, while a comparable bottle of Coke has 260 calories.
One of the arguments advanced by lawyers for Coca-Cola during the proceedings, strangely enough, was that this tactic wouldn't work because "no consumer could reasonably be misled into thinking Vitaminwater was a healthy beverage."
A settlement has been proposed in four states plus the U.S. Virgin Islands, but the case continues in California and New York, Howell says.
Meanwhile, similar suits have proceeded against PepsiCo's Naked Juice, POM Wonderful and Dr Pepper Snapple Group's 7UP Antioxidant drinks.
Beyond health-washing, critics worry that ubiquitous fortification might lead some people to get too much of an otherwise good nutrient, especially since half of Canadians also report taking vitamin or mineral supplements in pill form.
Researchers at Wake Forest School of Medicine in North Carolina recently published an assessment of overall vitamin and mineral intake in the general population in the journal Critical Reviews in Food Science and Nutrition. They concluded that fortified foods and drinks are increasing the number of people who exceed the safe upper limits for certain micronutrients. (Calcium, for example, is a crucial mineral but has been linked to increased risk of heart attack when taken in excess.)
While many vitamins are water-soluble, meaning you get rid of excess amounts in your urine, that doesn't mean it's impossible to get too much, Tarasuk points out. Large doses of vitamin C, which is water-soluble, can cause diarrhea, and recent studies have suggested that vitamin C supplements can block some of the fitness gains you would otherwise get from exercise.
One way to avoid this problem is to read the labels and monitor what you're getting. Under Health Canada's new rules, vitamin and energy drinks are treated as foods and have to include a standard panel displaying nutritional information. This is a big improvement over the situation when Tarasuk and her colleagues performed a similar analysis of novel beverages back in 2010. "We couldn't even find their calorie content, because they didn't have to declare it," Tarasuk recalls. "So most of the 'energy' drinks didn't tell you how much energy was in them."
Even among consumers who read labels carefully, after all, how many are really equipped to make a judgment about the merits or risks of quaffing, say, 500 per cent of your daily riboflavin needs?
In the end, vitamin overdose is hardly likely to emerge as the next big nutritional crisis. But with no apparent benefit and little understanding of the long-term effects of indiscriminate supplementation, Tarasuk believes we should at least be thinking more carefully about the pros and cons. Because under the current rules, she says, "I think we've embarked on an experiment on our population."
Alex Hutchinson blogs about exercise research at sweatscience.runnersworld.com. His latest book is Which Comes First, Cardio or Weights?