Cutting down on our sugar intake is important for preventing glucose intolerance and diabetes. One of the most popular swaps is sugar for artificial sweeteners, but are they really a healthier substitute? Keep reading to find out.
Content Outline
- Introduction
- What Are Non-Caloric Artificial Sweeteners (NAS)?
- The Link Between the Gut Microbiota and Glucose Regulation
- Do Artificial Sweeteners Increase Blood Sugar Levels?
- Tips for Supporting a Healthy Microbiota
- Summary
Introduction
Sugar has been a hot topic in nutrition for years. It’s ability to transform bland foods and drinks into sweet and tempting treats keeps us wanting more. However, it may surprise you to read that animal research has found that sugar can be more addictive than opioid drugs like cocaine[i].
Yet, like most addictive substances, in excess it’s not good for your body or health. For example, although sugar consumption may not directly cause life limiting illnesses like type 2 diabetes, the chances of developing it are increased.
To help curb their enthusiasm, many people look to make healthier swaps with their diet, and one of those may be replacing sugar with artificial sweeteners. Some research suggests that these may not be as healthy as they claim and may actually spike blood sugar and insulin levels. In this article, we explore some of the evidence behind these claims.
What Are Non-Caloric Artificial Sweeteners (NAS)?
Non-caloric artificial sweeteners (NAS) are popular and common food supplements that are used by millions of people to try and limit weight gain and combat diseases like type 2 diabetes.
Approximately 32% of Americans consume artificial sweeteners which are synthetic compounds and are much sweeter than sucrose (sugar) but have very few calories. Because they are unchanged as they pass through the digestive system and leave the body in the same form as they entered, they are known as ‘metabolically inert’. Therefore, they have no physiological effect[ii].
Common types of NAS
Artificial sweeteners can be found in just about anything from diet soft drinks to microwave meals and even chewing gum. Here are some of the common examples you might spot in an ingredients list:
- Aspartame
- Acesulfame potassium (Ace-K)
- Erythritol
- Saccharin
- Sorbitol
- Sucralose
- Xylitol[iii]
The Link Between the Gut Microbiota and Glucose Regulation
The microbial community in the intestinal tract is and important regulator of glucose levels in the body. The composition and activity of the gut microbiota can impact glucose homeostasis in several ways, including:
- Mediating the production of gut-derived serotonin: Peripheral serotonin can regulate blood sugar level balance[iv].
- Short chain fatty acid (SCFA) production: Microbial metabolites like SCFAs can influence the development of type 2 diabetes by modulating several physiological processes, including chronic low-grade inflammation, beta-cell dysfunction, and oxidative stress[v].
- Maintaining intestinal barrier integrity: A diverse and abundant gut microbiome ensures the security and integrity of the colonic lining, important for glucose regulation and fending off type 2 diabetes[vi].
- Regulating bile acid metabolism: Enzymes produced by the gut microbiota can alter bile acid production which can impact glucose and lipid (fat) metabolism[vii].
How Glucose Intolerance Develops
When you eat carbohydrate-containing foods, like bread, pasta, and potatoes, they are broken down into sugar which enters the bloodstream, causing a spike in blood glucose levels.
The rising sugar levels stimulate the release of insulin.
Glucose intolerance is an umbrella term encompassing several conditions that cause a higher-than-normal blood sugar level.
It occurs when insulin resistance – when your body’s cells don’t respond to the blood sugar-lowering hormone, insulin – worsens.
The most common cause is weight gain, but there are several other contributing factors, such as:
- Increasing age
- Sedentary lifestyle[viii]
Glucose intolerance has potentially serious consequences and is a precursor to type 2 diabetes.
Do Artificial Sweeteners Increase Blood Sugar Levels?
In the short term, no. For example, if you drink a glass of regular cola, your blood sugar levels will rapidly rise. However, if you drink a glass of diet cola containing artificial sweeteners, they won’t.
But there is quite a big but.
In 2014, Suez and colleagues published their research which concluded that artificial sweeteners can raise blood sugar levels through the alteration of the gut microbiota composition.
When mice were fed artificial sweeteners for 11 weeks, scientists observed negative changes in the gut microbiota, including an imbalanced microbiome (dysbiosis), resulting in increased blood sugar levels[ix].
When the bacteria from the mice fed artificial sweeteners were transferred to germ-free mice via faecal microbiota transplantation (FMT), the blood sugar levels were also raised in these mice. Yet, by reverting the gut bacteria back to normal, the blood sugar levels returned to within a healthy range.
In another study, rats were fed Ace-K for 4 weeks and scientists observed changes in the gut bacteria. However, there were distinct differences between male and female rats. For example, male rats gained weight when fed Ace-K, but females didn’t.
Is There Any Evidence in Humans?
The truth is, there are fewer studies conducted on humans, and some haven’t found any effect on the gut microbiome.
A study published in 2019 observed the gut microbiomes of 34 healthy human participants. Over 7 days, half were fed sucralose and the other half received a placebo. The researchers found no differences in glucose control, insulin resistance, or gut microbiota composition[x].
A two-week study explored the effect of sucralose and aspartame on the gut microbiomes of healthy individuals. Researchers stated that no changes were observed[xi].
However, some studies have noted some effects of artificial sweeteners on gut microbiome composition, but it’s complicated.
One study involved seven participants who didn’t normally consume artificial sweeteners for seven days. From day two until seven, the participants were fed the FDA's maximum daily saccharin intake.
The results showed:
- 4 out of 7 participants had poor blood sugar responses between days 5 and 7 compared to 1 to 4 – known as ‘responders’
- No changes were observed in the other 3 people, and these were referred to as ‘non-responders’
However, it was also found that the 4 responders also had different microbiomes compared to the other 3 participants before the trial began. So, although some people were more sensitive to the effects of saccharin, their gut microbiome composition was already different, and it changed during the trial which was linked to a poorer blood glucose response.
Overall, this suggests that gut bacteria changes could be linked to our starting microbiome composition, particularly as some participants exhibited no changes at all.
It means more research needs to be conducted before a definitive answer can be given to whether artificial sweeteners change the gut microbiota composition, affecting our blood sugar response.
Tips for Supporting a Healthy Microbiota
Maintaining a healthy and balanced gut microbiota is essential for many aspects of your health and well-being.
Here are some of the things you can try:
- Explore natural sweeteners: Try things like stevia, monk fruits, honey, maple syrup, and agave syrup rather than sugar and artificial sweeteners.
- Embrace whole foods for sweetness: Many foods offer natural sweetness like fruits, sweet potatoes, and carrots that also contain fiber, antioxidants and other health-promoting nutrients, making them a healthier option for your gut.
- Eat a diverse range of foods: Fill your diet with many different foods including fruit, vegetables whole grains, and legumes to encourage the growth of a diverse range of gut microbes.
- Include fermented foods: Experiment with foods like kefir, kimchi, sauerkraut, and miso that are rich in probiotics to help replenish and support your gut microbiota.
- Explore our PureHMO® range: Our range of human milk oligosaccharide products are prebiotic rich to help support a healthy gut microbiome.
Summary
Artificial sweeteners are often hailed as a guilt-free sugar substitute, but emerging animal research suggests they may have unintended effects on gut health and glucose regulation.
Although more studies are needed to establish the link between artificial sweeteners, gut microbiota composition, and glucose tolerance, especially in humans, minimizing your consumption of NAS and prioritizing gut-friendly habits, including consuming HMOs, could have protective benefits for your microbiome and lower your risk of developing conditions like type 2 diabetes.
Written by: Leanne Edermaniger, M.Sc. Leanne is a professional science writer who specializes in human health and enjoys writing about all things related to the gut microbiome.
Sources
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