Alternative sweeteners to sugar like agave syrup and stevia are often perceived as healthier options but they can also be overdone, a dietitian cautions. 
 
 As research links refined sugar to Type 2 diabetes and heart disease, some people are switching. 
 
 "Refined sugar, it's the new smoking, isn't it?" said Toronto dietitian Jennifer Sygo, author of Unmasking Superfoods. 
 
 CBC News asked Sygo about whether some alternative sweeteners are healthier than sugar. 
 
 "Somebody switching from table sugar to agave, will typically see less of a blood sugar spike," said Sygo. "It does have some redeeming nutritional properties, but they're small." 
 
 Agave, the plant used to make tequila, is higher in calories than sugar and three times as sweet. 
 
 Stevia has no calories, looks like sugar and is up to 300 times sweeter. 
 
 "We don't want to habituate our taste buds, get them used to sweet foods all the time," Sygo advised on using alternative sweeteners. 
 
 We don't want to habituate our taste buds to sweet foods all the time, says Jennifer Sygo. (CBC) 
 
 For non-nutritive, no calorie sweeteners, there's a contentious debate within nutrition circles about whether they make us crave sugar down the road. 
 
 "If you're going to use stevia, use it with caution," Sygo suggested. 
 
 At a bakery in Toronto, co-owner Ashley Whittig swears by organic agave nectar for sweet delights without the sugar rush. 
 
 "I don't feel as jacked up after," Whittig said. 
 
 But researchers have demonstrated a "healthy halo effect" — when you substitute something that is unhealthy with a food you perceive to be healthy, you end up eating more. For example, some people end up eating more ice cream when there are berries on top because they think the health value of the fruit allows them to consume extra. 
 
 "In general, we could all do well to reduce our need for highly sweet, sugary foods, no matter where they come from," Sygo said. ||||| Stevia is perhaps unique among food ingredients because it's most valued for what it doesn't do. It doesn't add calories. Unlike other sugar substitutes, stevia is derived from a plant. There is some question as to its effectiveness as a weight loss aid or as a helpful diet measure for diabetics. 
 
 The stevia plant is part of the Asteraceae family, related to the daisy and ragweed. Several stevia species called candyleaf are native to New Mexico, Arizona and Texas. But the prized species, Stevia rebaudiana (Bertoni), grows in Paraguay and Brazil, where people have used leaves from the stevia bush to sweeten food for hundreds of years. 
 
 Moises Santiago Bertoni, an Italian botanist, is often credited with the discovery of stevia in the late 1800s, even though the native Guarani people had used it for centuries. Known as kaa-he (or sweet herb) by the native population, the leaves of the plant had many uses. In traditional medicine in these regions, stevia served as a treatment for burns, colic, stomach problems and sometimes as a contraceptive. The leaves were also chewed on their own as a sweet treat. 
 
 It took Bertoni over a decade to find the actual plant, leading him to initially describe the plant as very rare. About the same time, more farms started growing and harvesting the stevia plant. Stevia quickly went from growing in the wild in certain areas to being a widely available herb. 
 
 Today, stevia is part of the sugar substitute market. According to the Federal Food and Drug Administration (FDA) high-purity steviol glycosides, an extract of the stevia plant, is considered generally safe for use in food. On the other hand, the FDA stated that stevia leaf and crude stevia extracts are not generally recognized as safe (GRAS) and do not have FDA approval for use in food. 
 
 The U.S. Department of Agriculture estimates Americans added more sugar to their diet every year since the 1970s until 2000. When Americans dropped the added sugar, they turned to sugar-like extracts. The sugar substitute market was estimated to be worth $13.26 billion in 2015, according an analysis by Markets and Markets research firm. The firm projected that the market would reach $16.5 billion by 2020. 
 
 Just 18 percent of U.S. adults used low- or no-calorie sweeteners in 2000. Now, 24 percent of adults and 12 percent of children use the sugar substitutes, according to a 2012 review in the American Journal of Clinical Nutrition. 
 
 Stevia has no calories, and it is 200 times sweeter than sugar in the same concentration. Other studies suggest stevia might have extra health benefits. 
 
 According to a 2017 article in the Journal of Medicinal Food, stevia has potential for treating endocrine diseases, such as obesity, diabetes and hypertension, but that more research is needed. 
 
 Other studies also suggest stevia could benefit people with Type 2 diabetes, but Catherine Ulbricht, senior pharmacist at Massachusetts General Hospital in Boston and co-founder of Natural Standard Research Collaboration, says more research is needed. Her group reviews evidence on herbs and supplements. 
 
 "Available research is promising for the use of stevia in hypertension," said Ulbricht. Ulbricht said Natural Standard gave stevia a "grade B for efficacy" in lowering blood pressure. 
 
 A no-calorie source of sweetness is an obvious diet solution in theory. But a few studies show that replacing sugar with artificial or low-calorie sweeteners may not ultimately lead to weight loss in real life. 
 
 A 2004 study in rats found low-calorie sweeteners led the animals to overeat, possibly because of a mismatch between the perceived sweetness and the expected calories from sugar, according to the paper in the International Journal of Obesity and Related Metabolic Disorders. The author of that study later argued that people who use artificial sweeteners may suffer health problems associated with excess sugar, including metabolic syndrome, which can be a precursor to diabetes. 
 
 "A number of studies suggest people who regularly consume ASB [artificially sweetened beverages] are at increased risk compared with those that do not consume ASB," Dr. Susan E. Swithers said in a 2013 opinion letter in the journal Trends in Endocrinology and Metabolism. 
 
 Yet there is also evidence that stevia does nothing to change eating habits or hurt metabolism in the short term. A 2010 study in the journal Appetite tested several artificial sweeteners against sugar and each other in 19 lean people and 12 obese people. 
 
 The study found people did not overeat after consuming a meal made with stevia instead of sugar. Their blood sugar was lower after a meal made with stevia than after eating a meal with sugar, and eating food with stevia resulted in lower insulin levels than eating either sucrose and aspartame. 
 
 Yet another study published in an issue of the International Journal of Obesity, Dec. 13, 2016, found that after eating no-calorie sweeteners, such as stevia, test subject’s blood sugar spiked much more than when they ate real sugar. Though, when using a zero-calorie sweetener, the subjects didn't consume any more calories than when regular sugar was consumed. "The energy 'saved' from replacing sugar with non-nutritive sweetener was fully compensated for at subsequent meals in the current study," Siew Ling Tey, who was a study researcher and is at the Agency for Science, Technology and Research (A*STAR) in Singapore, said in a statement. 
 
 As mentioned earlier, the question of whether stevia is safe to consume largely depends on what someone means by "stevia." The U.S. Food and Drug Administration has not approved stevia leaves or "crude stevia extracts" for use as food additives. Studies on stevia in those forms raise concerns about the control of blood sugar and effects on the reproductive, cardiovascular, and renal systems, the FDA warns. 
 
 However, the FDA has allowed companies to use Rebaudioside A, an isolated chemical from stevia, as a food additive in their sweetener products. The FDA classifies these products, such as Truvia, as GRAS, but, according to the FDA, these products are not stevia. "In general, Rebaudioside A differs from stevia in that it is a highly purified product. Products marketed as 'stevia' are whole leaf Stevia or Stevia extracts of which Rebaudioside A is a component," the FDA said. 
 
 There are some health concerns surrounding the stevia plant. Stevia may cause low blood pressure, which would be of concern to some taking blood pressure medications. There is also continuing research going into certain chemicals naturally occurring in stevia that may cause genetic mutations and cancer. 
 
 "Caution is advised when using medications that may also lower blood sugar. People taking insulin or drugs for diabetes by mouth should be monitored closely by a qualified health care professional, including a pharmacist," Ulbricht said. 
 
 Stevia may also interact with anti-fungals, anti-inflammatories, anti-microbials, anti-cancer drugs, anti-virals, appetite suppressants, calcium channel blockers, cholesterol-lowering drugs, drugs that increase urination, fertility agents and other medications, Ulbricht said. People should talk with their doctor before deciding to take stevia in large amounts, she said. 
 
 Additional reporting by Alina Bradford, Live Science contributor. 
 
 Additional resources ||||| Cornell scientists reduce sweetener stevia's bitter bits 
 
 Lauren Thiersch/Provided 
 
 Good news for consumers with a sweet tooth. Cornell food scientists have reduced the sweetener stevia’s bitter aftertaste by physical – rather than chemical – means, as noted in the Oct. 14 issue of the journal Food Chemistry. 
 
 “The food industry constantly evaluates and uses several alternate high-intensity sweeteners to duplicate the taste of sugar, usually with no calories,” said Samriddh Mudgal, M.S. ’15, lead author of the study. “Growing demand for natural ingredients have led to the rising popularity of steviol glycosides, which are natural sweeteners extracted from stevia leaves. They’ve been in use for centuries in South America. Since these steviol glycosides have a negligible effect on blood glucose, it is an attractive, natural sweetener for people on carbohydrate-controlled diets.” 
 
 Joining Mudgal on the research, “Controlling the Taste Receptor Accessible Structure of Rebaudioside A via Binding to Bovine Serum Albumin,” were Ivan Keresztes, director of Cornell’s NMR facility in the Department of Chemistry and Chemical Biology; Gerald W. Feigenson, professor of biochemistry, molecular and cell biology; and and Syed Rizvi, professor of food process engineering. 
 
 The findings could encourage the beverage industry, packaged dressings, cream sauces, powdered soups and dairy products to use more stevia. 
 
 While previous studies have focused on masking taste receptors, Mudgal and his colleagues took a different approach. One of stevia’s components is rebaudioside A – known as Reb A – the glycoside molecule that provides its sugary taste but yields a speck of bitterness that limits the sweetener’s commercial possibilities. When tasted now, Reb A activates two bitter receptors – hTAS2R4 and hTAS2R14 – on the human tongue. 
 
 The researchers modified Reb A by applying “hydrophobic effects” to the bovine serum albumin protein, which creates a stable Reb A-protein complex – and it essentially dissipates the Reb A molecular components. This protein solution disengages stevia’s bitter components, as the human tongue’s bitter receptors hTAS2R4 and hTAS2R14 are less likely to recognize the modified Reb A-protein complex. 
 
 The researchers tested the modified protein’s sturdiness in orange juice and found the sweet binding remained intact. Said Mudgal: “It’s a chemical-free, economical and purely physical interaction-based approach to control Reb A’s interaction with taste receptors, which will bolster its taste profile.” ||||| A crop of Stevia in Asuncion, Paraguay. REUTERS/Jorge Adorno (PARAGUAY) 
 
 Stevia, a natural, zer0-calorie sweetener, has been in the news lately as beverage companies like Coca-Cola have started using it in products as an alternative to artifical sweeteners. But some customers have had a negative reaction to the taste. 
 
 As we reported, fans of Vitaminwater took to Facebook to protest the use of stevia in the company's products, complaining it tastes like "chemicals" and "cough syrup." 
 
 Time to learn what all the fuss is about. 
 
 What Is Stevia? 
 
 In its natural form, Stevia rebaudiana is a leafy green plant found in Paraguay and Brazil. It has been used in those regions for hundreds of years as a sweetener and also "as a treatment for burns, colic, stomach problems and sometimes as a contraceptive," according to LiveScience. 
 
 The stevia plant contains several sweet-tasting compounds known as steviol glycosides, which have been estimated to be 200-300 times as sweet as sugar. 
 
 Stevia in its raw form is not approved for use as a food additive by the US Food and Drug Administration (FDA). However, the FDA approved one of the naturally-occurring compounds found in stevia, Rebaudioside A (Reb-A), in 2008. This means that most products currently being sold on grocery shelves labeled as "stevia" and approved for human consumption are probably highly-purified extracts of Reb-A. 
 
 This includes brand names like Truvia and Stevia in the Raw (made by the manufacturer of Sweet'N Low) and specialty drinks like Zevia. 
 
 Why Do Some People Think Stevia Tastes Bad? 
 
 In humans, taste buds on the tongue contain receptors to identify sweet and bitter chemical compounds. There is only one receptor that identifies sweet tastes, but there are 25 different receptors for bitter tastes. Chemical compounds found in the stevia plant interact with both the sweet and bitter receptors, leading to its signature bitter aftertaste. 
 
 That bitter kick is why, at least so far, beverages sweetened with stevia extracts mix in other sweeteners as well — like erythritol, aspartame, or plain old sugar. 
 
 A recent study in the Journal of Agricultural and Food Chemistry analyzed the different components of stevia to find out why certain compounds were perceived as more bitter. The findings will allow future development of stevia-derived sweeteners to focus on the sweetest, least bitter compounds derived from the plant. 
 
 And while some researchers are identifying the sweetest chemical compounds in stevia, others are working to breed the sweetest possible version of the stevia plant itself. 
 
 Ryan Warner, an associate professor in the Department of Horticulture at Michigan State University, is trying to create a sweeter stevia plant through selective breeding. Aside from Reb-A, there are a whole bunch of other compounds produced in the leaves of the stevia plant that have sweet-tasting properties, like stevioside, Reb-B through Reb-F, and Reb X. 
 
 "We're just trying to increase the concentration of the compounds that are sweeter but are normally produced in smaller in concentrations [in the plant]," he said. Warner's stevia research was funded for four years by PureCircle, a "producer of high purity stevia ingredients for the global food and beverage industry," according to the company's website. 
 
 And he's confident that the stevia plant will get sweeter and sweeter."People have been breeding wheat for thousands of years and gradually improving it. If you look at stevia, it has only been bred since the late 60s, early 70s," said Warner. "You can make some relatively big gains, relatively quickly, just by selecting the best plants. We've seen that you can pretty dramatically increase the concentrations of each of these different compounds in a few generations of breeding." 
 
 Research to make stevia more palatable is ongoing, but big beverage companies aren't waiting for perfect. Coca-Cola is gearing up to release Coke Life, its new soda that is flavored with a blend of sugar and stevia leaf extract, in the United Kingdom, where it already sells a similar version of Sprite. (There was an earlier launch of Coke Life in Argentina and Chile.) Stevia-sweetened Dr. Pepper, 7Up and CanadaDry are also in the works.
– Researchers at Cornell say they've figured out a way to conquer one of the big drawbacks of the sugar substitute stevia—its bitter aftertaste. They zeroed in on the component in stevia that triggers two bitter receptors on the human tongue and were able to modify it through non-chemical means, the scientists say in a university press release. Researchers tested the end result in orange juice and say the sweetness held up. "It’s a chemical-free, economical, and purely physical interaction-based approach to control Reb A’s interaction with taste receptors, which will bolster its taste profile," says the lead author of the study in Food Chemistry, using the shortcut for rebaudioside A. Stevia has gained popularity because it is derived from a plant, is much sweeter than actual sugar, and—the big one—has zero calories, notes a previous explainer at Live Science. But as Business Insider has reported, that "bitter kick" has held the sweetener back commercially. (Truvia and Stevia in the Raw are two big brand names featuring stevia.) The Cornell researchers say this finding could make the ingredient more common in beverages and all across the food industry. Still, the CBC notes that there's much debate among nutritionists over the pros and cons of stevia. "We don't want to habituate our taste buds, get them used to sweet foods all the time," says one. "If you're going to use stevia, use it with caution." (A study suggests that reducing kids' sugar intake improves their health remarkably quickly.)