Stevia: the sweet, plant-derived sugar substitute that's causing a debate in the nutrition world. In this article, I break down everything you need to know about stevia so you can feel confident making nutrition choices on your own.
What is Stevia and where does it come from?
Stevia is a zero calorie sugar substitute derived from the stevia plant, which is native to South America. Unlike other calorie free sweeteners, since stevia is extracted from a plant, it is considered to be the only sugar substitute that is both natural and calorie free. Even though stevia has just begun to gain popularity in supermarkets and common households, the stevia plant has actually been used for sweetening drinks and medicines since the 16th century. The leaves on the stevia plant contain many different chemical compounds called steviol glycosides – which are the sweet components of a stevia plant that are isolated, purified and used for sweetening. These chemical compounds give off a sweetness taste between 250 and 300 times sweeter than table sugar. Having such a high sweetness profile, it takes a smaller amount of stevia to acquire the same level of sweetness as table sugar. Therefore, you need less stevia in a recipe that calls for sugar to achieve the equivalent sweetness level.
Watch out: Other names for stevia found on a nutrition facts label include stevia extract, Rebaudioside A (Reb A), stevioside, and steviol glycosides.
How is stevia made?
Stevia leaves are harvested and the steviol glycosides are extracted from the stevia leaf, filtered, and then purified for consumption. This is very similar in process for obtaining vanilla from a vanilla bean. The sweet molecules in the stevia plant are extracted by crushing and steeping the dried leaves in water, then separating and purifying the best tasting steviol glycosides. The steps in extracting steviol glycoside include:
- Crushing the leaves.
- Extracting steviol glycosides with water.
- Filtering and separating the liquid steviol glycosides from the plant materials.
- Further purifying the extract with water or food grade alcohol.
- Drying the extract for obtaining high purity stevia leaf extract.
Purification is vital for observing the safety standards for food and beverage use.
Is stevia safe?
Yes, stevia has been labeled Generally Recognized as Safe (GRAS) by the American Food and Drug Administration (FDA). In order for a new food or beverage ingredient to enter the U.S. food supply, the ingredient must either be a FDA approved food additive or GRAS. GRAS is a term used by the FDA for deeming any substance, intentionally added to food, that has been adequately shown to be safe after various quality evidence based research.
In December of 2008, the USDA stated that highly purified stevia extract sweeteners that contain 95% or more steviol glycosides are generally recognized as safe and can be sold in the market.
Here’s A Tip: The Acceptable Daily Intake (ADI) of Stevia is up to 4 mg/kg of body weight
Likewise, there are no known side effects from consuming moderate amounts of stevia.
Why is stevia considered calorie-free?
When consumption of stevia occurs, the body is unable to absorb the steviol glycosides within the gastrointestinal tract. As the stevia passes through the stomach and colon, bacteria breaks down the steviol glycosides into smaller molecules of steviol. Steviol is then metabolized in the liver and ultimately excreted through the urine. This results in an inability to provide any energy, also known as calories, to the body. With no accumulation of stevia during metabolism, it can, therefore, be considered calorie free.
Even though this is true, just because sugar is replaced by stevia doesn’t automatically mean a person will lose weight. For example, just because a person baked cupcakes made with stevia doesn’t make it acceptable to eat ten. It is important to understand the additional unhealthy qualities within that cupcake such as fat, butter, and refined grains will inhibit someone from reaching their goals.
What are the health benefits of stevia?
As we have learned, stevia is calorie free, therefore, it does not affect blood sugar levels. Without containing carbohydrates, stevia is a great recommendation for diabetes management. Additionally, stevia is known for having a glycemic index of zero. The Glycemic index is a numbered scale from 0-100 that determines how quickly sugar enters the bloodstream in the body. A low glycemic index, what a person strives to achieve, has a value of less than 55 and a high glycemic index is over 70. Although, studies have found that stevia does trigger an insulin response, it does not have an affect on blood glucose levels. This insulin response caused by stevia is not the same as table sugar.
While stevia is a great supplement for people with diabetes, anyone can use stevia as part of a heart healthy diet to maintain weight or lose weight due to its calorie free properties
Studies have concluded that pregnant women and children can also consume reasonable amounts of stevia without any adverse side effects.
While current research provides a positive view on stevia, further research continues to be conducted as it is still a relatively new sweetener.
Did you know: The stevia plant contains the antioxidant kaempferol which has been found to reduce the risk of pancreatic cancer by 23%.
What to look for when buying stevia? What are the different brands of stevia and how do they compare to each other?
Stevia comes in many different brands and forms on the market. Stevia can come in a liquid form and a granulated or powdered form. Always check the ingredient lists because some stevia brands contain added ingredients which can be misleading when searching for stevia. The purpose of these added ingredients are to tone down the intensity of sweetness from pure stevia extract. Added ingredients to can include sugar alcohols, the most common being erythritol, starches such as dextrose and maltodextrin, and plant fibers such as agave inulin.
Brand(s) that contains the sugar alcohol, erythritol:
- Truvia
- Pyure
Brand(s) that contains dextrose:
- Stevia in the Raw
Brand(s) that contains agave inulin:
- Wholesome Organic Stevia
SweetLeaf Liquid Stevia Drops contain only purified water, stevia leaf extract, and natural flavors.
How does stevia compare to artificial sweeteners and sugar alcohols?
Artificial sweeteners are made up of molecules that do not exist in nature, unlike stevia which is derived from a plant.
There have been numerous studies with conflicting evidence on the effects of artificial sweeteners. Some studies show that regular use of artificial sweeteners reduces a person’s intake of calories and promotes weight loss or maintenance, other research has shown no effect on intake or weight, while other research says the opposite. Overall, artificial sweeteners are manmade and chemically modified and should be avoided when wanting to live a healthy lifestyle.
What are sugar alcohols?
Sugar alcohols are neither a sugar nor an alcohol. Sugar alcohols are altered by adding hydrogen atoms to sugar. The chemical structure of a sugar alcohol partially resembles carbohydrates and partially resembles alcohol, although it does not contain ethanol which is found in alcoholic drinks. While sugar alcohols are naturally occurring in fruits and vegetables, products such as sorbitol, xylitol, erythritol, and maltitol are chemically processed by altering the natural sugar found in these fruits and vegetables. If the sugar alcohol is natural, like in an orange, it is more than appropriate to consume. Although, if you see a bar with a laundry list of ingredients and a sugar alcohol is one of them, it is most likely process and you should stay away.
Did you know? Sugar alcohols have been known to cause a laxative effect for some people.
Bottom line: Not only is stevia used as a healthy alternative for sweetening beverages and food, it is also a great supplement for anyone wanting to control their glycemic index and weight. Stevia is natural, unlike artificial sweeteners and sugar alcohols. Remember, not all stevia products are created equal and it is important to use stevia in moderation. Using stevia is not justification for consuming large amounts of any food just because it contains zero calories.
Resources:
http://www.stevia.com/Stevia_article/Questions_Answers_about_Stevia/2269
http://www.medicalnewstoday.com/articles/287251.php
http://www.stevia.org/stevia-information/stevia-safety
http://caloriecontrol.org/wp-content/uploads/NUTRITION-NEWS-Sweet-Facts-about-Stevia.pdf
http://www.health.harvard.edu/diseases-and-conditions/glycemic_index_and_glycemic_load_for_100_foods
http://www.fda.gov/food/ingredientspackaginglabeling/foodadditivesingredients/ucm397716.htm
https://www.hsph.harvard.edu/nutritionsource/healthy-drinks/artificial-sweeteners/
http://www.foodinsight.org/Sugar_Alcohols_Fact_Sheet
https://www.sugar.org/other-sweeteners/sugar-alcohols/
http://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1201&context=extension_curall