The truth about sugar substitutes
We sifted through the latest research on diet pop and sugar substitutes
From long-used artificial sweeteners such as aspartame to plant-based sweeteners such as stevia (derived from Stevia rebaudiana), there are lots of sugar substitute choices. They have clear benefits: They don’t cause tooth decay and they can be a good choice for people with diabetes or high blood sugar. But are they safe? To update ‘The Truth About Artificial Sweeteners,’ published in the November/December 2009 issue of Best Health, we scoured the health journals to get the latest research, and spoke with experts on the subject to get the most up-to-date recommendations.
Are they safe?
Any sugar substitute approved by Health Canada is considered safe. ‘These products have been studied at length,’ says Dr. Arya M. Sharma, a professor of medicine and chair of obesity research at the University of Alberta. ‘Toxicology studies have found little evidence that any approved sugar substitute is harmful.’ The Canadian Cancer Society (CCS) gives Health Canada-approved sugar substitutes the green light, too. ‘They have not been linked to higher cancer risk in humans,’ says the CCS.
However, there may be benefits to limiting or avoiding certain ones during pregnancy.
Does diet pop make you fat?
It’s not certain. Research has linked diet drinks to weight gain; a 2011 University of Texas Health Science Center San Antonio study showed that over 10 years, people who had two or more diet pops per day had waist-size increases 500 percent greater than non-diet-pop drinkers. The challenge for researchers: It can be difficult to prove diet pops are to blame, since overweight people may be more inclined than healthy-weight people to drink them. So which came first: the weight gain or the diet pop?
In a 2011 Harvard Health Letter, David Ludwig, director of the New Balance Foundation Obesity Prevention Center at Boston Children’s Hospital, proposed that since sugar substitutes are hundreds to thousands of times sweeter than table sugar, habitual consumers could become desensitized to sweetness. They might find foods such as fruit and vegetables less appealing’and replace those calories with refined carbs and unhealthy fats.
Khosrow Adeli, head of clinical biochemistry at Toronto’s Hospital for Sick Children, sees some cause for concern. When you eat sugar, receptors on the tongue and in the gut taste sweetness and signal the brain and intestine to secrete hormones that help absorb and metabolize sugar, explains Adeli. Artificial sweeteners trigger the taste receptors’but sugar never enters the gut. ‘Evidence suggests it can confuse the system and over time, lead to a higher appetite for sweeter foods.’ One or two cans of diet pop a week, even for children, is unlikely to harm metabolism, he says, ‘but we don’t know the long-term consequencesof consuming them more often.’
All in all, the research has not made any clear links. ‘There are a lot of plausible theories but I haven’t seen any good studies to support the idea that artificial sweeteners cause you to gain weight,’ says Sharma.
Is diet pop linked to diabetes?
A 2009 study in Diabetes Care associated daily consumption of diet pop with a 67 percent greater risk of type 2 diabetes. In 2013, French epidemiologists studying 66,000 women made the same connection. In their study (published in The American Journal of Clinical Nutrition), drinking regular or diet pop raised the risk of developing type 2 diabetes, but drinking juice did not. The study was conducted on a very lean population, so pre-existing weight problems can’t explain the results.
Researchers say users of artificial sweeteners are not immune to developing diabetes because, like sugar, the sweeteners may generate spikes in blood glucose and, subsequently, insulin.
The bottom line: As a population we are eating too much added sugar. The World Health Organization recommends they make up no more than 10 percent of your daily calories. If you choose to replace sugars with artificial sweeteners, products approved by Health Canada are deemed safe, and the Canadian Cancer Society says they have not been linked to higher cancer risk in humans.
Approved by Health Canada in 2012 for use as a tabletop sweetener and a sweetener in certain foods, steviol glycosides are calorie-free sweeteners. They are made from purified extracts of the stevia plant (Stevia rebaudiana), which is native to South America.
In the 1990s, Health Canada and the U.S. Food and Drug Administration rejected stevia for use as a food ingredient when it was shown to cause infertility and cancer-causing genetic mutations in animal studies. But Health Canada recently revised its guidelines to allow stevia and its extracts to be used in natural health products, which include beverages. Stevia sweeteners are now permitted in Canada and promoted as natural alternatives to artificial sweeteners.
The brands currently on the market include Truvia, Pure Via and SweetLeaf; they were developed from extracts of stevia that are 97 percent pure, called rebaudioside A. They are 200 times sweeter than sugar. Still, some experts, including those at the CSPI, are concerned about stevia’s health effects and are calling for more rigorous testing. We will keep you posted of any emerging news.
You’ll see it on the label’s ingredients list as ‘steviol glycosides,’ ‘stevia leaf extract,’ ‘rebiana’ or ‘Reb A’. The Health-Canada-recommended acceptable daily intake is 12 mg per kg, or about 10 packets.
Another natural high-intensity sweetener, thaumatin has been on the market for 30 years and is approved by Health Canada as a natural health product. Made from extracts of the West African katemfe fruit, it is often used as a food additive in breath fresheners and chewing gum.
In Spring 2013, Health Canada completed a safety assessment of monk fruit (or Luo Han Guo) extract, another plant-based, calorie-free sweetener, for use as a tabletop sweetener. Monk fruit, which has been consumed in China for hundreds of years, is 250 times sweeter than sugar.
What are sugar alcohols?
Health Canada does not categorize sugar alcohols as artificial sweeteners. ‘They contain calories, so they are not technically artificial sweeteners,’ explains Burke Bulloch, a Saskatoon-based registered dietitian. So what are they?
Chemical names: Erythritol, xylitol, maltitol, mannitol, sorbitol and hydrogenated starch hydrolysates (HSH)
Used in: Hard candy, chocolates, jams, ice cream and other sugar-free foods. They are also sometimes used to mask the bitter aftertaste of other sugar substitutes, including stevia.
Details: Health Canada has approved them, but says they are not absorbed well by the small intestine. They can have a laxative effect and lead to gas, bloating, diarrhea and cramps when consumed in large quantities. Some varieties (such as maltitol and xylitol) contain three quarters the calories of sugar, so these particular sugar alcohols may be a less optimal choice than others for people with diabetes.
When to avoid: Keep intake to under 10 grams per day if you are concerned about caloric intake or gastrointestinal effects.
Health Canada-Recommended acceptable daily intake (ADI): Health Canada has not specified an ADI, but Dietitians of Canada says more than 10 grams/day can cause abdominal discomfort. That’s about two hard candies, 10 pieces of gum or two chocolates sweetened with sugar alcohols.