Artificial sweeteners, such as those contained in diet drinks, don’t actually help people lose weight, a new Canadian study suggests. In fact, they appear to be linked to weight gain and an increased risk of diabetes. 
 
 Dr. Meghan Azad and a team of researchers of the University of Manitoba conducted a meta-review of 37 previously published studies that looked at the diet habits of more than 400,000 people. 
 
 The team found no good evidence that regularly consuming artificial sweeteners led to weight loss. In fact, the longer observational studies showed a link between the sweeteners and higher risks of weight gain and obesity, high blood pressure, diabetes, and other health issues. 
 
 The full results appear in the Canadian Medical Association Journal (CMAJ). 
 
 Azad said what her team was most struck by was the lack of good, rigorous studies on artificial sweeteners. 
 
 “Surprisingly, given how common these products are, not many studies have looked at the long-term impact of their consumption,” Azad told CTV News Channel from Lisbon, Portugal. 
 
 She noted that only seven of the 37 studies they reviewed were randomized controlled trials (RCTs), and all were relatively short, following participants for a median period of only six months. 
 
 The other 30 studies were longer and followed the participants for an average of 10 years, but they were observational studies – a form of research that is not as precise as a controlled trial. 
 
 “A lot of the studies we found were observational, meaning they could show a link but they can’t prove a cause-and-effect relationship,” she said. 
 
 Among the seven RCT’s, regular consumption of sweeteners had no significant effect on weight loss. From the other studies, the team found that regular use of sweeteners was associated with an increased risk of type 2 diabetes and high blood pressure, and modest increases in weight and waist circumferences. 
 
 “What we found was that at the end of the day, from all of this research, there really wasn’t firm evidence of a long-term benefit of artificial sweeteners. And there was some evidence of long-term harm from long-term consumption,” Azad said. 
 
 As for why artificial sweeteners seem to be linked to weight gain, not weight loss, Azad says no one knows for sure but there are lots of theories. 
 
 One theory is that the sweeteners somehow disrupt healthy gut bacteria. Another theory is that the sweeteners confuse our metabolisms, causing them to overreact to sugary tastes. 
 
 It could be that those who regularly use artificial sweeteners over-compensate for the missed calories from sugar, or they could have otherwise unhealthy diets in conjunction with sweetener use. 
 
 Azad would like to see a lot more research on the long-term use of sweeteners, in particular studies that could compare the different sweeteners, to see if one is any better than another. 
 
 In the meantime, for those trying to cut down on their sugar consumption, Azad says it’s important not to switch from one harmful food item to another. 
 
 “I think the takeaway for Canadians at this point is to maybe think twice about whether you really want to be consuming these artificial sweeteners, particularly on an everyday basis,” Azad said, “because really we don’t have evidence to say for sure whether these are truly harmless alternatives to sugar.” ||||| Consumers may want to think twice about relying on artificial sweeteners, says a Manitoba researcher who found no evidence the sweeteners help with weight loss and some potential health harm beyond the waistline. 
 
 People are increasingly consuming artificial sweeteners such as aspartame and sucralose as well as the non-nutritive sweetener stevioside, derived from the stevia plant. The sweeteners are widespread in food and drinks including diet soda, yogurt, sauces and dressings and baked goods. 
 
 Health sciences Prof. Meghan Azad was one of them, reaching for the low-calorie choices until she started researching them in detail. 
 
 "Over 40 per cent of adults are reporting using artificial sweeteners on a regular basis," said Azad. "We know a lot of people are consuming them in foods and not realizing it." 
 
 In Monday's issue of the Canadian Medical Association Journal, Azad and her co-authors scrutinize 30 observational studies that followed more than 400,000 people in the general population for about a decade, as well as seven randomized trials of about 1,000 people with obesity who were followed for an average of six months. 
 
 While those who are obese were trying to use the artificial or non-nutritive sweeteners as part of weight-loss program, Azad found no consistent benefits in helping the needle go down on the scale or slimming the waist. 
 
 No clear benefit, potential for harm 
 
 What's more, studies on those consuming artificial sweeteners routinely suggest the intake may be associated with cardiovascular disease events such as heart attacks and strokes, Type 2 diabetes and hypertension. 
 
 "There's no clear benefit and there's potential for harm, so for me, it's worth it to just choose water instead," Azad said. 
 
 While researchers conducting the observational studies took into account factors such as the overall quality of participants' diets and pre-existing health conditions, no cause-and-effect relations can be drawn. 
 
 At her lab, Azad is now studying what happens when people are given artificially sweetened beverages for several weeks. The scientists are collecting fecal samples to analyze gut microbes for metabolic biomarkers. 
 
 The experiment is meant to investigate the hypothesis that artificial sweeteners shift the gut flora in a way that predisposes us to obesity. 
 
 Another possibility, Azad said, is that we compensate and think that drinking a diet pop permits us to enjoy pizza and cake later. 
 
 Another possibility is that our bodies have evolved to metabolize sugars in a way that's triggered not by calories or the sugar molecule but by the perception of sweet taste. 
 
 Azad suggests that consumers who turn to artificial sweeteners on the assumption that they're a healthier choice should to be cautious. More research is needed to understand the long-term effects. 
 
 Diabetes Canada lists Health Canada's approved sweeteners in its guidelines. 
 
 Dr. Sean Wharton, an internal medicine specialist in Toronto who works with patients on weight management and management of diabetes, said he generally tells people to avoid artificial sweeteners. But he's not convinced the sweeteners cause Type 2 diabetes. 
 
 "T​hey may lose weight for a little while and go back up for lots of other reasons, not just because of sugar or sweeteners," said Wharton. "There's psychological issues, there's other medical issues, family issues. These people tend to be at risk in the first place. So we can't use these studies to say that these sweeteners are the problem." 
 
 A taste for the artificial 
 
 Montreal journalist and blogger Marissa Miller isn't fazed by the warnings. 
 
 Over 40 per cent of adults report using artificial sweeteners. (Jenny Kane/Associated Press) 
 
 "I'm a real junkie," Miller said. She uses a variety of artificial sweeteners in her coffee, tea, cereal, on bitter fruit, in smoothies and in baking. 
 
 Miller was raised by health-conscious parents who gave her diet juices. As a child, having sugar felt foreign. Miller said when she tried to quit as an adult, she hated real sugar. 
 
 "Any time I have sugar, I have this overwhelming sense of panic," Miller said. 
 
 To her, artificial sweeteners still offer the best of both worlds of sweetness without the calorie cost. "Everyone has their vices. I don't think this is something to worry about."
– If you think you're avoiding artificial sweeteners because you don't put them in your coffee or tea, think again. These additives are found in everything from yogurt and baked goods to sauces and diet colas, per the CBC, with "a lot of people ... consuming them in foods and not realizing it," says University of Manitoba researcher Meghan Azad. Azad, the co-author of a new study published Monday in the Canadian Medical Association Journal, also notes that 40% of adults report using artificial sweeteners on a regular basis—which may prove pointless when it comes to dropping pounds, as her team has found no evidence that the sweeteners help with weight loss and may even cause other health issues. Azad's team conducted a meta analysis of 37 previously published studies of the diets of nearly 407,000 people, only seven of which were randomized control trials. "A lot of the studies we found were observational, meaning they could show a link, but they can't prove a cause-and-effect relationship," she tells CTV News. Among the seven more-rigorous trials, regular consumption of artificial sweeteners had no significant effect on weight loss, while among the 30 observational studies, regular consumption was tied to a higher risk of Type 2 diabetes and high blood pressure, as well as "modest" weight gain. Possible reasons for the weight gain, per Azad: Our bodies may metabolize based on sweetness perception (not sugar content), gut bacteria affected by sweeteners may affect obesity, or we may give ourselves permission to eat more sweets after eating diet products. An internal medicine expert says the studies aren't clear enough to cast all blame on artificial sweeteners; Azad says there isn't enough evidence the sweeteners are "truly harmless." (When it comes to higher blood sugar, gut bacteria may play a role.)