Doctors consistently warn us about the health risks of excessive sugar consumption, yet many of us have a genuine fondness for indulging in the sweet life, or "la dolce vita." Could artificial sweeteners potentially provide a more health-conscious substitute?
First, let's take a closer look. Many artificial sweeteners, also known as sugar substitutes, are much sweeter than sugar.
"Chemically, they're a wide range of substances that are differently structured and work differently," said Dr. Stefan Kabisch from the Department of Endocrinology and Metabolic Medicine at Charite University Hospital in Berlin. Some are absorbed in the intestines, others aren't. Some even have a bitter aftertaste.
"Compared with sugar, (intense) artificial sweeteners have the advantage of causing no tooth decay and being calorie-free," said Katrin Böttner, a food and nutrition specialist at the consumer advice center in the German state of North Rhine-Westphalia.
Twelve are currently approved for use in the European Union, including acesulfame K (E950), aspartame (E951), cyclamate (E952), saccharin (E954), and stevia glycosides from Stevia (E960a), the last of which is a natural, plant-based sweetener.
Sugar alcohols are another type of sugar substitute. "They're all structured similarly," said Kabisch. Eight are currently approved for use in the EU, including erythritol (E968), sorbitol (E420) and xylitol (E967).
They're about as sweet as sugar or less so. And they have calories, but fewer than sugar – except erythritol, which has none.
"It's not broken down by bacteria in the intestines, but completely resorbed and excreted via urine," Kabisch said. "Erythritol can be used, for example, for baking, just like sugar."
Consumed in large amounts, however, sugar alcohols can cause gastrointestinal problems such as flatulence and diarrhea. "Individual tolerance varies," notes Böttner. "You should know this, as you may not attribute these symptoms to them."
But back to the original question: Are artificial sweeteners a healthier alternative to sugar?
To answer this, it's important to realize that your sugar intake doesn't consist only of refined sugar added to foods. Natural sugars are found, for instance, in fruits as well as in honey and agave nectar – "liquid sugar that healthwise hardly differs from refined sugar," Kabisch said.
While sugar is an energy-rich nutrient, we can survive without it for decades. Our body is evolutionarily programmed to love eating sugar and to utilize lots of it though.
"At the time this program took hold, we went long periods without food," explained Kabisch. "So it made sense to lay in fat reserves." This isn't the case today, but sugar intake still activates the brain's reward system.
It's difficult to quantify a "healthy" intake of sugar. According to the World Health Organization (WHO), calories in the form of sugar shouldn't exceed 10% of a person's daily calorie intake. So if your daily calorie requirement is, say, 2,000, you shouldn't consume more than about 50 grams of sugar.
This applies only to free sugars, however – that is, to sugars added to foods or drinks, or that are naturally present in honey, syrup, and fruit juices. It doesn't include the sugars found in fruit, vegetables, and milk.
"Sugar is definitely problematic from a health standpoint, sugar substitutes less so," said Kabisch, adding that there's insufficient research on which of the sugar substitutes – intense artificial sweeteners or sugar alcohols – is the healthier alternative.
He and Böttner agree that the evidence is unclear, the data spotty, and many studies flawed.
"At the end of the day, you've got to consider and decide for yourself," Böttner said. "Although the majority of studies haven't shown sugar substitutes to be harmful to health, much more research needs to be done."
Kabisch points out that observational studies have shown that a disproportionate number of people who excessively consume artificial sweeteners are overweight and diabetics.
"Reverse causality is probably at work here though," he said. In other words, the sweeteners aren't to blame for their condition, but rather they consume them to help control their diabetes.
"Less research has been done on sugar alcohols, but it's already clear that they alter intestinal flora," he said. So people with a bowel condition, such as Crohn's disease or irritable bowel syndrome, should be careful.
Both Kabisch and Böttner recommend a long-term reduction in sugar intake, arguing that the healthiest course of action isn't to satisfy your craving for sweets by switching to artificial sweeteners, but by curbing the craving.
This takes self-discipline and staying power – it's not enough to avoid sugary foods for a few days now and then. "You've got to lastingly wean yourself off the urge to eat sweets," Kabisch said. "It's harder for some people than others, but can be done."
Checking the lists of ingredients when you go grocery shopping is a good idea too.
"Artificial sweeteners are in more processed foods than you may think," said Böttner, not only in sugary drinks but also where you wouldn't expect them. On ingredient lists, they must be identified as "sweeteners" or marked with an E number.
