The truth about artificial sweeteners. A doctor’s take.
Low calorie sweeteners are a tried and tested option for those wishing to get that sweet kick with little or no calorific consequence. So how do they work? Are they bad for you? Will they help you lose weight? Scroll to find out.
How do artificial sweeteners work?
Your tongue contains thousands of taste buds, each containing a number of taste receptors that detect a variety of flavours. When you eat, these receptors come into contact with food or drink molecules, resulting in a signal being sent to your brain, enabling you to identify the taste. Artificial sweetener molecules work in a similar way to real sugar, they activate the sweet “pathway” although, they are often many times more sweet than sugar.
What are the most common artificial sweeteners?
Some of the most common artificial sweeteners include sucralose, aspartame and saccharin. Sweeteners such as xylitol and sorbitol are molecularly closely matched to sugar. They’re actually natural sugars made from sugar alcohol. Alternatives like Stevia, are considered more "natural" as they are plant-derived, although, they're still produced in a lab.
Are they safe?
Short answer, yes. All artificial sweeteners undergo a rigorous safety assessment by the European Food Safety Authority (EFSA) before they can be safely used in food and drink. There’s also no evidence to suggest they increase the risk of diseases such as cancer. Click here for a link to a meta analysis review paper. Sweet.
Will they help me lose weight?
Probably not. It’s quite common for people to choose artificial sweeteners over sugary foods to help control their weight however, the evidence is relatively inconclusive. Some studies actually show the opposite, claiming that artificial sweeteners can make you feel hungrier. How can this be? Science. After consumption, artificial sweeteners do not increase blood sugar levels, therefore they do not impact satiety as much as real sugar containing foods. Interestingly, a study from the University of Sydney determined that after chronic exposure to a diet containing the artificial sweetener sucralose, they saw that animals began eating a lot more. They found that “inside the brain’s reward centres, sweet sensation is integrated with energy content. When sweetness versus energy is out of balance for a period of time, the brain recalibrates and increases total calories consumed.” They then investigated why animals were eating more food (even though they had enough calories). They found that chronic consumption of this artificial sweetener actually increases the sweet intensity of real nutritive sugar, and this then increases the animal’s overall motivation to eat more food. Here’s a link to the paper. It’s worth noting that the research surrounding the topic of “artificial sweeteners and weight gain” shows mixed findings. The majority of the studies available are observational studies, where the theory of reverse causation is possible.
Artificial sweeteners have several benefits, including helping decreasing the amount of added sugars in your diet and limiting tooth decay, as well as being safe to consume. On the other hand, they may lead to more sugar cravings because artificial sweeteners are not real sugar. The recommended maximum limit of free sugars are 30 grams a day for anyone 11 years or older. For perspective, a cup of apple juice contains about 24 grams of sugar. Our chewable vitamins contain about a gram of sugar. As for most things in life, including your diet, balance is key.
Dr Zobir Alexander, MB ChB, BSc (Hons) - Senior Writer