Cousin of the chrysanthemum, sibling of the sunflower, it is called 'stevia' and it is incredibly sweet.

Stevia is 300 times sweeter than sugar. It's illegal, at least when sold in concentrated forms. Some people say that's bound to change.

Agriculture Canada is growing stevia. "We want to turn it into a crop, a viable crop for farmers in southwestern Ontario," says Jim Brandle, a plant breeding specialist with Agriculture Canada.

But approval to use stevia to sweeten your coffee will require costly research.

Jim Brandle

"It's going to take some work on the part of someone more on the commercial side than on the research side to make sure that it gets approval as a food additive," says Brandle. "People have to want to buy it so it's going to take some marketing."

According to Bill Barratt, stevia is "a natural sweetner, and there's no calories." Barratt runs Royal Sweet, which has fields of stevia in California, and has a patented process for refining the sweet essence from the leaves.

Barratt wants to see products sweetened with stevia on every store shelf in North America. He says its bound to happen: "This is going to be the sweetener of the millennium, there's no question in my mind."

Bill Barratt

Stevia is native to Paraguay. The people of Paraguay and Brazil have used it for centuries to make a sweet herbal tea.

In recent years, stevia has made its way to the Far East. It has been embraced in Japan, where it's used in soy sauce, sweet pickles and soft drinks. In Japan, Diet Coke has been sweetened with stevia.

Stevia has also taken root in North America, but just barely. Carolyn Ross of Oakville, Ontario, uses stevia and notes that only a fraction of stevia will produce the same sweetness as sugar.

Ross has a sweet tooth, and a family history of diabetes. Also, for her, stevia comes with a bonus: "I like the fact that it's a natural product. It's a herb."

Carolyn Ross

But in Canada, so far, stevia can only be sold as a herb. Strictly speaking, the processed stevia Ross uses is not legal. Agriculture Canada is betting the farm that will change.

Marketplace asked Barratt what he thinks of the long-term future of stevia here. Is it something we can expect to see in tiny packets side-by-side with sugar?

"I hope it will," he says. "because as I said before, the food additive issue has to be addressed."

The food additive issue he's talking about is this: while Agriculture Canada may be growing it, Health Canada forbids stevia's use as a sweetener in foods.

Linda Bonvie

On that, Health Canada and the U.S. Food and Drug Administration agree.

Linda Bonvie says they're wrong. She's a New Jersey-based investigative journalist who's written a book on stevia. On its cover she asks 'Is the FDA suppressing an ideal herbal sweetener?'

"I think suppression is the perfect word here," she says. "Starting with the import alert ... keeping it out of the country is suppression."

Bonvie, who also runs a website on stevia use in North America, adds that the objections to stevia are unfounded.

Celestial Seasonings brewed a herbal tea with stevia for a while

Once upon a time, stevia could be used in the U.S. Celestial Seasonings brewed a herbal tea with stevia for a while. Lipton Tea had the same idea, but couldn't get approval. In 1991 someone complained to the FDA that stevia had not been proven safe, and all commercial use was put on hold.

In the U.S. today, as in Canada, stevia is sold only in health food stores. Sugar and artificial sweeteners have the supermarket shelves to themselves.

Bonvie says she believes that the sweetening industry has pressured the FDA to keep stevia out of the United States:

"I think there's a lot at stake here ... and when there's big money at stake, strange things happen."

David Schardt is a nutritionist with the Centre for Science in the Public Interest, which looks out for consumers and is often critical of the FDA. But not about stevia.

David Schardt

He says: "we've heard those stories that it was Monsanto that manufactures aspartame, or Nutrasweet, that blew the whistle on stevia and got the FDA to ban it as a food additive.

"We don't know whether that's true or not. It's impossible to say whether that really happened or not, but there are doubts about the safety of stevia."

Schardt says there are some concerns that have kept stevia from being approved for use.

"There are questions about the effect on the reproductive tract in animals," he says. "Questions that it might possibly be converted into a mutagen and maybe cause cancer."

Linda Bonvie is convinced stevia is safe

There have already been 900 stevia studies. Nineteen of them indicated problems according to the Food and Drug Administration. One study in 1968 determined stevia might cause 'decreased fertility' in rats.

Schardt says "none of these have been adequately resolved by good studies." But despite such evidence, Linda Bonvie is convinced stevia is safe. "I like the fact that it's been around for centuries, that's a really big selling point in my book."

How can it be that this product has been used for centuries in South America, for decades in Japan, and these matters remain unresolved?

Schardt has an answer: "The Japanese don't consume all that much of it, and if larger amounts consumed over a long period of time cause some kind of chronic disease that took a long time to develop, say cancer, ... would you really notice that somebody who got cancer may have been consuming stevia some ten or twenty years earlier? It's debatable."

Bonvie doesn't buy that. "There's been no consumer complaints or reports of ill effects due to stevia," she says. "Not in health journals, not in government statistics, and not by consumers.

"I was told that Canadian consumers had complained about stevia and I asked about that. I was told the complaint was, 'Where can I buy stevia?'"

Carolyn Ross can buy stevia in Oakville, but now she wonders if she should.

"I wonder if we could find out more about stevia," Ross says. "Is it truly a pure herb and are there long term side effects?"

Schardt admits "it may be that with further experiments and further research we'll find that stevia would really not be a problem at the amounts that consumers would be consuming." But he cautions that "right now the record shows stevia shouldn't be approved yet until there's more reseach."