Artificial Sweeteners, Excess Sugar, and Possible Health Problems
The Problem With Sweetening Food
For many people, consuming sweetened food and beverages is an enjoyable part of daily life. The potential dangers of eating too much sugar are well known. Unfortunately, replacing sugar with artificial sweeteners may not be helpful. Recent studies have highlighted some potential health problems caused by sugar and certain artificial sweeteners. The studies suggest that many of us need to change the way in which we sweeten our food.
Researchers in Israel have found a possible explanation for why people who replace the sugar in their diet with certain artificial sweeteners often fail to lose weight and may even gain weight. Scientists at the Weizmann Institute of Science have discovered that some artificial sweeteners can change the composition of the bacterial population living in the gut, which may lead to glucose intolerance and high blood sugar.
Another research project by the World Health Organization and some British researchers suggests that the currently recommended limits for daily sugar consumption are far too generous. A high level of sugar in the diet increases the risk of many health problems, including tooth decay and obesity.
Common Artificial Sweeteners
Artificial sweeteners are made synthetically and don't occur in nature. People like them because they have zero or virtually zero calories and don't cause tooth decay.
The sweeteners in the table below have been approved for use in the United States by the FDA (Food and Drug Administration). Although various people have made claims that the sweeteners are unsafe, the FDA disagrees.
Interestingly, the decisions of health agencies in other countries are sometimes different from those of the FDA. For example, until quite recently Health Canada didn't allow the use of saccharin as a sweetener. On the other hand, Health Canada does allow the use of cyclamate as a sweetener, while the FDA doesn't.
Since artificial sweeteners are so much sweeter than sugar, they must be used in small quantities and mixed with another substance before use. The table below shows that neotame is 8000X sweeter than sugar. This isn't a typing mistake. Artificial sweeteners bought in stores are mixed with a starch derivative to dilute them. This adds calories to the sweetener, but the number is so small that the sweetener is still said to have zero calories.
Artificial Sweeteners Approved for Use in the United States
Digestion and Absorption
About 200X sweeter than sugar
Not digested or absorbed
Also known as acesulfame-potassium
200X sweeter than sugar
Digested into aspartic acid and phenylalanine, which are absorbed
Mustn't be used by people with phenylketonuria
200X to 700X sweeter than sugar
Not digested or absorbed
Derived from petroleum
About 600X sweeter than sugar
Not digested; a small amount is absorbed and then excreted
Made by adding chlorine to sucrose
8000X sweeter than sugar
Digested into aspartic acid and phenylalanine, which are absorbed
Metabolized like aspartame but is structurally different
Research in Mice and Humans
The Israeli investigation exploring the relationships between artificial sweeteners, gut bacteria, and metabolic changes was especially interesting because it was first performed in mice and then in humans. A discovery made in mice is often true for humans, but not always. In this case, however, the researchers found similar results in both mice and people.
Like humans, mice have a large population of bacteria living in their large intestine, or gut. These bacteria play an important role in mouse and human lives and form a "microbiome". Many of the bacteria are helpful. A few are harmful. In a healthy individual the level of harmful bacteria is usually low, however.
Artificial Sweeteners, Glucose Intolerance, and Gut Bacteria in Mice
The mouse study at the Weizmann Institute of Science investigated the effects of saccharin, aspartame, and sucralose on the blood glucose (or blood sugar) level. Mice fed water containing the artificial sweeteners experienced a dramatically increased risk of developing glucose intolerance compared to mice given water alone or water containing table sugar. The level of artificial sweetener consumed by the mice was equivalent to the level considered to be safe for our bodies.
Glucose intolerance is the inability of the body to deal with large amounts of glucose correctly. The amount of glucose in the blood rises as a result, a condition known as hyperglycemia. The disorder can lead to metabolic syndrome and type 2 diabetes, also known as adult onset diabetes.
In the second part of the experiment, the researchers divided the mice being fed artificial sweeteners into two groups. The scientists gave the mice in one group antibiotics to eliminate most of the bacteria living in their gut. Once this was done, the ingestion of artificial sweeteners no longer caused glucose intolerance in the mice. The researchers then obtained samples of gut bacteria from glucose intolerant mice. When this sample were inserted into the healthy mice, they became intolerant to glucose.
Artificial Sweeteners, Glucose Intolerance, and Gut Bacteria in Humans
The Weizmann Institute researchers asked seven people who didn't use artificial sweeteners to use saccharin as a sweetener for one week. The researchers tested the volunteers' blood glucose level at regular intervals. At the end of the week, four of the volunteers had an increased blood sugar level and signs of glucose intolerance. The sample size in this experiment was very small, but the results suggest that the body's response to an artificial sweetener may not be the same in everyone.
The researchers also analyzed data from nearly 400 people enrolled in the Personalized Nutrition Project. This study is designed to examine the relationship between nutrition and gut bacteria. The scientists found that people who reported that they used artificial sweeteners had a different bacterial population in their gut compared to those who didn't use the sweeteners. They also found that the population of a bacterium known to cause inflammation in the gut was greatly increased in people who used artificial sweeteners.
Other research also indicates that there might be a link between artificial sweeteners and the health of gut bacteria. In 2018, researchers from Israel and Singapore found that all of the artificial sweeteners classified as safe by the FDA had harmful effects on a bacterium closely related to one in our gut.
Some of the researchers studying the effects of artificial sweeteners say that their discoveries are "preliminary", but they've raised a lot of interest. More studies are needed to confirm the discoveries and to determine how the sweeteners affect our intestinal bacteria and our bodies.
Definitions: Carbohydrates, Sugars and Sugar
Carbohydrates are chemicals that our bodies use for energy production. They are essential in our diet, but like any nutrient they can be harmful in excess. Carbohydrates that aren't required for energy production are stored as fat.
Three main types of carbohydrates exist—monosaccharides, disaccharides, and polysaccharides. Monosaccharides are made of one molecule, disaccharides consist of two monosaccharide molecules joined together, and polysaccharides are made of many monosaccharide molecules joined together to form chains.
Monosaccharides and disaccharides are often known as "sugars". Three examples of monosaccharides are glucose, fructose, and galactose. Some common disaccharides made from these monosaccharides are listed below.
- Maltose is made of two glucose molecules joined together. It's found in germinating grains.
- Sucrose is made of a glucose molecule and a fructose molecule joined together. Sucrose is also known as sugar, table sugar, or cane sugar. It's obtained from sugar cane and sugar beets.
- Lactose is made of a glucose molecule and a galactose molecule joined together. It's found in milk.
Although the terms "sugar" and "sugars" can be confusing, in general the word sugar refers specifically to sucrose and the word sugars refers to all monosaccharides and disaccharides.
Is Sugar Toxic?
Our small intestine digests sucrose into glucose and fructose, which enter the bloodstream. Glucose is absorbed by the cells in our tissues and is used to produce energy; fructose is absorbed by the liver and metabolized.
Some people claim that sugar is toxic because of the fructose that it contains. They say that excess fructose ingestion causes fatty liver disease. Most scientists are skeptical of this claim, however. They say that a huge amount of fructose would need to be ingested in order to cause liver problems in humans.
The problem is not that sucrose is a harmful molecule—although it does feed oral bacteria if it lingers in the mouth—but that many people eat large amounts of concentrated sucrose on a daily basis. Some of this is deliberately added at home to sweeten food. However, most of the sugar that we ingest has already been added to the processed foods and drinks that we buy.
Health Problems Caused by Excess Sugar Consumption
The detrimental effects of excess sugar consumption that have been best studied are tooth decay, weight gain, and obesity.
There is a direct correlation between the amount of sugar consumed and the amount of tooth decay. Bacteria that live in the mouth feed on the sugar, producing acids that destroy tooth enamel. Starchy foods and foods and drinks that are high in other sugars can also cause cavities. Evidence suggests that it's more harmful to eat cariogenic (cavity-causing) foods between meals than with meals. It's not a good idea to eat a lot of sugar at any time, though.
Weight gain and obesity increase the risk of other health problems, including type 2 diabetes and high blood pressure. Being overweight also increases the risk of several types of cancer and some types of cardiovascular problems. In addition, it can make osteoarthritis worse. Other factors besides sugar can contribute to an increase in weight, including eating excess calories and not exercising.
Research has shown that eating a large amount of sugar at one time temporarily depresses the activity of the immune system. This is not something that we want to do, since our immune system fights bacteria and viruses that enter the body.
Reducing Sugar in the Diet
The latest advice from the World Health Organization, or WHO, is that added sugar should account for a maximum of 5% of our daily calories. This is lower than the previous recommendation of 10%. Some researchers say that the total should be reduced to 3% of total calories.
Five to six teaspoons of sugar would provide about 5% of the daily calorie intake in an average woman. Six to eight teaspoons would be needed to reach this limit in a man. If a person ingests some common processed foods or drinks they will very quickly reach or exceed the limit. For example, a can of a sweetened cola drink typically contains ten teaspoons of sugar.
Unfortunately, food and drink labels show sugar content in grams, not teaspoons (at least here in Canada), but converting grams to teaspoons is easy. 4 grams of sugar equals 1 teaspoon, so dividing the sugar content in grams by 4 will give the number of teaspoons of sugar. Another problem is that quantities on processed food labels include sugars naturally occurring in the food as well as added sugars, so some judgement is needed when assessing the labels.
Philip James from the London School of Hygiene and Tropical Medicine recommends that some strict steps be taken to reduce our sugar consumption. He says that a sugar tax should be applied to foods that are high in sugar and that vending machines selling sugary foods and drinks should be removed from organizations such as schools and hospitals.
Natural and Semi-Natural Sweeteners
There are many natural sweeteners that can replace refined table sugar as a sweetener. Most of these are high in monosaccharides or disaccharides, however.
- Honey has a reputation as a healthy food, but it has disadvantages as well as benefits. Although some types of honey do contain useful chemicals such as antioxidants and antibacterial substances, honey is also rich in fructose and glucose.
- Agave nectar and syrup are rich in fructose.
- Brown rice syrup is high in maltose.
- Maple syrup is rich in sucrose.
- Corn syrup contains glucose and maltose. High-fructose corn syrup is a very highly processed form of corn syrup and is rich in fructose. This is definitely not a natural sweetener.
- Blackstrap molasses is rich in sucrose but is also a significant source of some important minerals, including calcium and iron.
- Unrefined sugar has a lovely taste but is almost completely sucrose. It contains minerals, but in the serving sizes that most people use the quantity of extra nutrients is insignificant.
- Stevia is becoming a popular sweetener. It's extracted from the leaves of the stevia plant. Unlike the sweeteners above, stevia's sweetening power doesn't depend on sugars. The main chemicals responsible for its sweetness are stevioside and rebaudioside. Stevia doesn't contribute to tooth decay.
A Dentist Talks About Sugar Alcohols
Polyols or Sugar Alcohols
Members of a family of chemicals known as polyols or sugar alcohols have a sweet taste and can be used as sweeteners. A sugar alcohol is classified as a carbohydrate but not as a sugar or an alcohol, despite its name.
Sugar alcohols occur naturally in nature. They contain fewer calories than sugar and don't cause tooth decay. They may affect blood sugar, but to a lesser extent than sucrose. Some popular examples of sugar alcohols are described below.
- Xylitol has some important health benefits, including preventing tooth decay and helping certain ear infections in children. It's a deadly substance for dogs, however.
- Erythritol doesn't cause problems in pets and is well tolerated by most people when used in small to moderate amounts. This is my favourite sweetener. I don't use xylitol because there are dogs in my family and I don't use maltitol or sorbitol due to the problems described below.
- Maltitol and sorbitol are also members of the polyol family. Their use may cause gastric distress and diarrhea. Some people find that their digestive system gradually becomes more tolerant of these sweeteners, while others don't.
Using Whole, Unprocessed Foods as Sweeteners
Sugars are sometimes classified as intrinsic and extrinsic. Intrinsic sugars are located within the cells of a food. Intact fruits and vegetables contain intrinsic sugars, for example. Extrinsic sugars are those that are added to a food or drink—such as to sweetened cereals or beverages—and others that are not located inside the cells of the food and are "loose". Even unsweetened fruit juice contains extrinsic sugars, and so do smoothies made from chopped and blended fruits.
Intrinsic sugars are healthier for us than extrinsic ones. Even though intrinsic sugars are released as cells are broken down in the digestive tract, the fibre in the cells slows both their release and their absorption into the body. The body can handle a relatively slow release of a moderate amount of sugar much better than a flood of concentrated sugar.
Dried fruits contain intrinsic sugars. They are often considered to be healthy sweeteners because they are whole foods. They do contain fibre, but they also contain concentrated sugars due to the loss of water in the drying process. Since they are often small in size, it's easy to eat too many dried fruits.
Apart from dried fruits, most foods containing intrinsic sugars don't taste as sweet as those containing extrinsic sugars. When people wean themselves from extrinsic sweeteners, however, they sometimes find that the intrinsic sugars in whole foods and spices provide sufficient sweetness for their taste.
Choosing a Sweetener
Choosing a sweetener is a personal choice. A person needs to consider both the advantages and the disadvantages of using a particular extrinsic sweetener. Care is needed with intrinsic sweeteners, too. Eating very large amounts of the sweetest fruits is probably not a good idea.
I'm content eating most of my food without added sweeteners. There are a couple of exceptions, though. I add erythritol to my oatmeal and coffee. I occasionally eat a food contain added sugars for a special occasion, but I have to be very careful that the "special occasions" don't happen too often.
The effort to reduce the use of sweeteners if necessary and to choose suitable ones is well worthwhile, since they can have a big effect on our health. Learning how to prepare tasty foods without using an added sweetener can help a person to both enjoy their food and to stay healthy.
Artificial sweeteners and other sugar substitutes (The Mayo Clinic)
Comparing artificial sweeteners (WebMD)
Artificial sweeteners could cause spikes in blood sugar (The Washington Post)
More research suggesting that some artificial sweeteners may be harmful for gut bacteria from Business Insider
Sugar intake must be slashed further (BBC)
This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.
© 2014 Linda Crampton