Artificial sweeteners may make you fat

Sugar Substitutes dark side

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Synthetic Sweeteners can make you eat more

Sugar substitutes (also known as artificial sweeteners) not only provide a low-calory and sweet sugar-like taste to many foods, they also have an effect on your body and its metabolism.

The $1.15 billion global artificial sweetener market is based on the notion that these products are GRAS, that is, Generally Regarded As Safe for consumption.

But is this really the case? What are the side effects of these artificial sweeteners? Are they bad for you?

Studies show that by being sweet but lacking calories they disrupt the body's metabolism:

chronic consumption of a sweet   ⁄ energy imbalanced diet... increases the motivation to eatWang et al., 2016

In this article we will review some scientific papers to learn more about sugar substitutes and their pros and cons.

Are these sugar substitutes good for you?.

Artificial Sweeteners

Artificial sweeteners are man-made sugar substitutes, food additives that give foodstuffs and beverages a sweet taste with a lower (or nill) content of energy. They are therefore low-calorie or even zero-calorie sweeteners.

How are Artificial Sweeteners made?

Science also calls them Nonnutritive sweeteners (NNS). The first one to be synthesized was Saccharin. It was created by a chemist named Constantin Fahlberg, who obtained it from coal tar derivatives in 1879.

Sodium Cyclamate (banned in the US, but not in the EU) followed in 1937, Aspartame in 1965, Acesulfame Pottasium (or Acesulfame K) in 1967, Sucralose in 1976 and Neotame in 1996.

All of the above mentioned artificial sweeteners are al synthetic products, manufactured by chemical processes in industrial facilities, and the FDA considers them GRAS (Generally Regarded As Safe for consumption).

Only one Sugar Substitute is "natural"

Then there is Stevia, a "natural" zero-calorie sweetener, which is obtained from a South American plant. However use of stevia leaves (which contain about 10% of sweetening stevioside and rebaudioside A) and crude stevia extracts are not considered GRAS by the FDA who only regards as GRAS the refined high-purity steviol glycosides extracted from the plant's leaves. ( 1 )

So even though stevia is a plant, the steviol glycosides are extracted from the leaves with water, followed by an alcohol solvent and crystallization. Some brands add other chemicals such as erythritol (another low-calorie natural sugar).

Artificial Sweeteners are found everywhere

Even if you don't deliberately consume them, you are exposed to them as sweeteners in some medications, in tooth paste and mouthwash for instance. They are used in diet sodas, sports drinks, low-sugar candies, fruit juices, flavored iced teas, and processed foods.

A Multibillion Industry

Synthetic Sucralose is probably the most pervasive artificial sweetener ( 2 ) as it is found in around 4,500 different types of foods, and accounts for 62% of the $1.15 billion global artificial sweetener market.

Sugar-free sweeteners have an impact on the environment

Despite being approved as safe for human use, their eco-toxicity is matter of debate.

These man-made chemicals (at least in theory) are not broken down by the human digestive system so they enter sewage unaltered (excreted in urine and feces). They then enter wastewater treatment plants where the microbial digestors cannot break them down either, and are discharged in the treated water (or as raw sewage in developing countries) into the environment.

To make matters worse, (Shaoli Li, et al., 2018) ( 3 ) found that the presence of artificial sweeteners "did inhibit microbial activity and microbial community structure", and that a mix of different types of artificial sweeteners had a greater impact on them than the individual ones.

Ace-k and sucralose can be found in concentrations of up to µg per liter in surface-waters and aquifers placing these concentrations of chemicals "among the highest known for anthropogenic trace pollutants". ( 4 )

So we are discharging vast amounts of non-digested artificial sweeteners into our water supplies, where they are absorbed by fish, plants, insects and crustaceans.

Synthetic Sweeteners and your health

Despite the fact that the FDA regards artificial sweeteners as GRAS, they aren't biologically inert. They are supposed to pass through your body without being digested (that is why they are low or zero calorie sweeteners: your body cannot obtain any energy from them as it can't break them down), but some recent evidence suggests otherwise:

Sucralose is stored in fatty tissue

A recent paper by Bornemann et al., (2018) ( 5 ) found that sucralose can be metabolized in the gut of rats producing two fat-soluble or "lipophylic" compounds.

This differs from studies which were presented to the FDA to obtain its regulatory approval, which stated that sucralose was not broken down in the body, something which was reassuring, meaning that it could not be absorbed or metabolized.

This new study also reported that sucralose was detected in the rats' fatty tissue two weeks after the rats had stopped being fed sucralose, meaning that it stays inside the body, where its potential health effects are unknown.

Take Home Point

Sucralose can be absorbed by your body's fatty tissue. It is also metabolized in your gut.

Adverse side-effects of Artificial Sweeteners

Pepino (2010) ( 6 ) describes how these supposedly "metabolically inactive" man-made sweeteners can upset the balance of human metabolism:

  1. Artificial sweeteners interfere with the microbes that live in the gut.
  2. They interact with sweet-taste receptors in the digestive system and this upsets insulin production, glucose control and the body's energy balance.

As a result this increases the "risk to develop obesity, metabolic syndrome, and type 2 diabetes."

A study with fruit flies and mice (Wang et al., 2016) ( 7 ) explored how artificial sweeteners upset metabolism to provoke increased appetite and sleep disruption:

They fed fruit flies sucralose with their regular food (they ate the same amount of calories as usual), and found that those that ate this diet for a long period of time (for flies this was 5 days or more - which is equivalent to approx. 8 years for a human being) increased their intake of food and calories.

They concluded that "sucralose has an appetite stimulating effect" which made the flies consume 30 percent more calories when they were later given a naturally sweetened food.

Fortunately the effect is reversible: after 3 days of not eating sucralose their appetite returned to normal levels.

The study found that sucrose interacts with sweet taste neurons, which triggers the fly's insulin system and increases their appetite.

Additionally it "promotes hyperactivity, insomnia, and sleep fragmentation". This is because the combination of a sweet-taste which lacks calories induces a "mild starvation or fasting state" which alters behaviour besides increasing hunger pangs.

They then tested mice (some ate sucralose sweetened jelly and the others none), those eating sucralose "showed a significant increase in food intake".

Take Home Point

Sucralose increases appetite making you eat more.

Impact on gut microbes

Gut microbes can keep us in good health by taking part in our digestive process (fermentation food), assisting in the development of immune cells, regulating the intestinal nervous system, and blocking intestinal colonization by pathogens. The balance of the up to 1,000 microbial species in our intestines is therefore critical for good health.

According to Wang et al., (2018) ( 2 ) consuming artificial sweeteners "alters the relative proportion of intestinal microbial phyla" this is due to the sweetener's bacteriostatic effect (they stop bacteria from reproducing or growing):

"Synthetic sweeteners acesulfame potassium, saccharin and sucralose all exerted strong bacteriostatic effects... [and] rebaudioside A, the active ingredient in the natural [artificial sweetener] stevia, also had similar bacteriostatic properties".

In mice, sucralose increased the quantity of a strain of bacteria called Firmicutes which is something that is also found in obese mice but not in their lean littermates.

Abbot et al., (2014) ( 10 ) reported that the gut microbiome disruption caused by artificial sweeteners may be the cause behind metabolic disease. They studied mice, feeding them with different synthetic sweeterners and after 11 weeks the animals had glucose intolerance. They fed different groups of mice with different diets: some ate a normal diet, others a high-fat one, and their water was spiked either with glucose or glucose plus saccharin.

The mice drinking saccharin spiked water had a higher glucose intolerance compared to the group that only drank water with glucose.

Saccharin altered the gut microbes to cause glucose intolerance:

  • The scientists transplanted faecal matter from glucose-intolerant saccharin fed mice into the intestines of mice which had been bred to have sterile gut, and as expected the transplanted bacteria colonized their hosts' intestines and made them become glucose intolerant.
  • When the mice were given antibiotics to kill the microbiome, glucose intolerance was prevented.

Take Home Point

Artificial sweeteners alter your gut's microbiome and this may cause metabolic syndrome.

Daily intake levels

The US Food and Drug Administration -FDA- ( 8 ) sets a maximum "acceptable daily intake" level for each of the approved sweeteners. This level is based on the available scientific evidence and according to the FDA makes these "high-intensity sweeteners ... safe for the general population under certain conditions of use".

Nevertheless, back in 1998, the American Dietetic Association stated that artificial sweeteners should not be used in children younger than 2 years of age and minimal or totally restricted during pregnancy and lactation ( 9 ).

Not so sweet is it?

These studies clearly show us that sugar-free sweeteners are not inert and do interact with our bodies.

They upset the balance of the microbes in our gut, which has an impact on our overall health, an impact which is still being studied.

It also appears to make us hungry and eat more; it increases our glucose intolerance and this tends to cause obesity.

Natural sugars have the drawback of being energy rich and even worse are the "added sugars" found in many processed foods and beverages (read our blogpost: Sugar the poison added to our food), so a low or zero calorie option is good if you are trying to lose weight.

Artificial sweeteners can help you cut out unnecessary calories and help you on your weight loss program, but they do have their negative aspects.

Cite this article:

. ©2018. Artificial Sweeteners make you fat. Patagonia Wellness, 22 Dec. 2018.

Tags: artificial sweeteners, sugar-substitutes, synthetic sweeteners, weight, microbiome

Subject: Artificial Sweeteners risks: sugar-substitutes are sweet low or zero calorie food additives which entail health risks: altered microbiome, enhanced appetite and risk of metabolic disease.


References and Further Reading

(2) Wang QP, Browman D, Herzog H, Neely GG., (2018). Non-nutritive sweeteners possess a bacteriostatic effect and alter gut microbiota in mice. PLoS One. 2018;13(7):e0199080. Published 2018 Jul 5. doi:10.1371/journal.pone.0199080

(3) Shaoli Li, Jinju Geng, Gang Wu, Xingsheng Gao, Yingying Fu, Hongqiang Ren, (2018). Removal of artificial sweeteners and their effects on microbial communities in sequencing batch reactors. Scientific Reports vol 8, Art. no 3399 21 February 2018

(4) Harpaz D et al., (2018). Measuring Artificial Sweeteners Toxicity Using a Bioluminescent Bacterial Panel. Molecules. 2018 Sep 25;23(10). pii: E2454. doi: 10.3390/molecules23102454

(5) Volker Bornemann, Stephen C. Werness, Lauren Buslinger, Susan S. Schiffman, (2018). Intestinal Metabolism and Bioaccumulation of Sucralose In Adipose Tissue In The Rat. Journal of Toxicology and Environmental Health, Part A, 2018; 1 DOI: 10.1080/15287394.2018.1502560

(6) Pepino MY, (2015). Metabolic effects of non-nutritive sweeteners. Physiol Behav. 2015 Dec 1;152(Pt B):450-5. doi: 10.1016/j.physbeh.2015.06.024. Epub 2015 Jun 19

(7) Qiao-Ping Wang et al., (2016). Sucralose Promotes Food Intake through NPY and a Neuronal Fasting Response. Cell Metabolism, 2016; 24 (1): 75 DOI: 10.1016/j.cmet.2016.06.010

(9) Duffy VB, Anderson GH., (1998). Position of the American Dietetic Association: Use of nutritive and nonnutritive sweeteners. J Am Diet Assoc. 1998;98:580-7