Editors at the Canadian Medical Association Journal are wondering why caffeine pills need health warnings guarding against their use in children, yet no such warnings exist on "energy drinks," which can contain twice as much caffeine.

The editors say the caffeine levels in energy drinks can be sky-high, with the caffeine equivalent of 10 cans of cola or five cups of coffee.

And though Health Canada suggests kids under 12 shouldn't consume more than 85 milligrams of caffeine a day -- and even less among younger kids -- some energy drinks sold in Canada contain as much as 500 mg per can.

"Caffeine-loaded energy drinks have now crossed the line from beverages to drugs delivered as tasty syrups," write Dr. Paul Hébert, CMAJ's editor-in-chief, Dr. Noni MacDonald, section editor of population and public health at CMAJ, and Dr. Matthew Stanbrook, CMAJ's scientific deputy editor.

They note that while many coffee drinks can contain high levels of caffeine, they aren't marketed to kids the way energy drinks are.

"Energy drinks are often targeted toward children and youth through carefully designed advertising campaigns as well as sponsorship of events such as snowboarding and skateboarding competitions," they write.

They say the real problem is that caffeine levels are not clearly marked on most energy drink cans and bottles. For example, while manufacturers need to state on product labels how much synthetic caffeine their drinks contain, they're not required to state the amount of caffeine is found in the product's herbal ingredients, such as guarana.

The editors say youth "can hardly be expected to make appropriate decisions about consuming energy drinks when information on caffeine concentration and appropriate safe amounts is not visible on these products."

The editors say they would like to see government-mandated restrictions on labelling, sales and marketing, of energy drinks as well as industry-wide standards with clear labeling accompanied by public education.

Refreshments Canada, which represents the Canadian non-alcoholic beverage industry, issued a news release Monday to take issue with what it called "a number of inaccuracies" in the CMAJ editorial.

"We strongly agree that energy drinks should be marketed responsibly," the group said.

"Energy drinks are intended for adults and clearly indicate on the label that this category of beverage is not recommended for children, pregnant or breastfeeding women and people who are sensitive to caffeine."

In added that, contrary to the editorial, energy drink labels do list intended population for its drinks, as well as any precautions (such as not mixing with alcohol), and declaration of caffeine content from all sources.