Stevia is a zero-calorie natural sweetener that has gained popularity in recent years. Once available only in the health food stores, this sweetener is now widely available. Made from the Stevia rebaudiana plant, this sweetener is 200 times sweeter than sugar. Though highly refined and purified glycosides of stevia are considered safe by the FDA, there are still some concerns about its side effects. In this article, we will learn about stevia and the various side effects associated with this sweetener.
What is stevia?
Stevia belongs to the Asteraceae family, which is related to daisy and ragweed. More than 200 species of stevia grow in South America, but Stevia rebaudiana is the most sought after variety. This bushy shrub is native to northeast Paraguay, Brazil, and Argentina. It grows in many other parts of the world now, including Europe, parts of Asia and Canada. Stevia leaves are 200 times sweeter than regular sugar. There are two compounds in stevia that are responsible for its sweetness – Stevioside and Rebaudioside A.
While rebaudioside A is extracted and used in stevia sweeteners, it is usually not the only ingredient. Most stevia sweeteners also contain erythritol from corn, dextrose, and other artificial sweeteners. Stevioside make only 10 percent of the sweetness in stevia but has a bitter aftertaste that many people do not like. It also provides most of the beneficial properties of stevia.
Many raw or less processed forms of stevia contain both these compounds. The United States Food and Drug Administration (FDA), however, consider only high-purity steviol glycosides safe for human consumption. The FDA has not approved crude stevia extracts, and stevia leaves as a food additive.
History of stevia
The Guarani Indians of South America have used the leaves of the Stevia plant (traditionally known as a Kaa he-he) for centuries. They used the sweetening power of the leaves of stevia shrub to enhance the taste of bitter made and medicinal potions. By the 1800s stevia use had spread from Paraguay to countries like Brazil and Argentina.
In 1899 a Swiss botanist Moises Santiago Bertoni described the plant and its sweet taste while researching eastern Paraguay. In 1931 two French chemists isolated the two glycosides that give the stevia leaf its sweet taste. They named them stevioside and rebaudioside.
Stevia’s history with the FDA
In 1991 stevia was banned in the US due to some studies that said that it might cause cancer. A few later studies refuted the results of this study, and in 1995, the FDA allowed the import and use of stevia as a food supplement but not a sweetener. Several companies then asked the FDA that stevia should be recognized as ‘Generally Recognized as Safe’ (GRAS) just like many other sweeteners.
Substances that are considered GRAS are determined to be safe through expert consensus and are exempt from rigorous approval processes needed for food additives. In 2008 FDA declared stevia GRAS and allowed its use in mainstream US food production.
Stevia is now used in Gatorade’s G2, Vitamin Water Zero, SoBe Lifewater Zero, Crystal Lite, and Sprite Green. It is also used all over the world in chewing gums, wines, candies, soft drinks, and yogurts.
Side effects of stevia
While most people tolerate stevia well, some people may develop some side effects. Over the years, many studies have identified the side effects of stevia, but most of these studies were done on animals, and many of them have been disproved. Here are some of the potential side effects that have been linked to stevia use –
1. Kidney damage
According to the National Kidney Foundation, some studies have shown that stevia can have adverse effects on the kidneys. Since this is a relatively new sweetener, they advise you to use it in moderation. Since stevia is a diuretic, it increases the speed with which the body expels water and electrolytes. Since Kidneys are responsible for filtering and creating urine, researchers thought stevia might damage the kidneys. A recent study has refuted this side effect. According to a recent study, stevia can reduce cyst formation and growth in patients of polycystic kidney disease (1).
2. Gastrointestinal issues
Some stevia products may contain added sugar alcohols. These sugar alcohols can cause digestive problems like nausea, indigestion, vomiting, cramping, and bloating. According to the Memorial Sloan-Kettering Cancer Centre, some patients who consumed 500 mg of stevioside powder, reported adverse reactions like nausea and abdominal fullness. Reducing the amount of stevia consumed can lower the symptoms.
Stevia belongs to the Asteraceae family of plants which includes ragweed, chrysanthemum, marigolds, daisies, and many other plants. People who are allergic to the Asteraceae family of plants may also be sensitive to stevia. There are a few reported cases of stevia allergy. However, according to the FDA and European Commission, the risk of having a stevia allergy is very low.
Some research shows that stevia contains chemicals that might lower blood sugar and interfere with blood sugar control. It was also thought that long term consumption of stevia might cause hypoglycemia. Recent research has proven this to be unlikely, except in people with exceptionally low blood sugar levels. However, if you have diabetes and take stevia, you must monitor your blood sugar levels carefully.
Stevia acts as a vasodilator. It causes the blood vessels to widen, which lowers the overall blood pressure. This effect of stevia can be a matter of concern for people with chronic low blood pressure. If you have low blood pressure, check with your healthcare provider before taking stevia.
6. Endocrine disruption
Steviol glycosides can interfere with the hormones that are controlled by the endocrine system. According to a 2016 study, when human sperm cells were exposed to steviol, they experienced an increase in progesterone production (2).
7. Numbness in hands and feet
Long term use of stevia can affect the peripheral nervous system, which consists of sensory nerves that send and receive messages from the spinal cord and brain. Stevia may also affect the central nervous system and slow down nerve conduction velocity. Taking too much stevia can lead to tingling and numbness in hands and feet.
8. Drug interactions
Stevia can also interact with diabetes and blood pressure medications. It also interacts with lithium.
Is stevia safe during pregnancy?
The FDA deems rebaudioside A as safe during pregnancy as it has been given the GRAS rating. However, if you have a sensitivity to sugar alcohols, choose a brand that does not contain erythritol. However, high doses or long term use of trivia during pregnancy can increase the workload on organs like kidneys, bladder, and heart and worsen pregnancy symptoms.
Taking too much stevia during pregnancy can lead to dehydration, low blood pressure, constipation, kidney dysfunction, fatigue, headaches, mood swings, nausea, and low blood sugar. Whole-leaf stevia and crude stevia extracts are also not safe to use while you are pregnant.
The appropriate dosage for stevia depends on age, sex, and the user’s health. The acceptable daily intake of stevioside is 5 mg per kilogram of body weight per day and 4 mg per kilogram of body weight for rebaudioside. These figures show that the acceptable daily intake of FDA approved purified extract is 12 mg per kilogram of body weight. You must keep in mind that even though stevia is a natural product, dosages are important. Follow the directions on the label and consult with a doctor before using.
Benefits of stevia
Over the years, the benefits of stevia have been researched a lot. Here are some of the benefits of stevia –
1. Helpful for people with diabetes
People with diabetes who have to avoid sugar can benefit from using stevia. According to a 2010 study, having stevia before a meal reduced after-meal blood glucose and insulin levels (3).
2. Reduces cancer risk
A 2012 study linked stevioside to cancer apoptosis and decrease in pathways that cause cancer growth (4). Stevia contains antioxidant compounds like kaempferol that can reduce the risk of pancreatic cancer.
3. Weight loss
Stevia is a zero-calorie sweetener. Replacing sugar with stevia can reduce sugar and calorie intake, which is helpful in weight loss.
4. Improves cholesterol levels
Studies have shown that stevia helps to decrease triglycerides and LDL levels while increasing HDL levels (5).
5. Lowers high blood pressure
According to research, some glycosides in stevia dilate blood vessels and increase sodium excretion, which helps to keep blood pressure at a healthy level.
Stevia is a plant that belongs to the Asteraceae family. This bushy shrub is native to northeast Paraguay, Brazil, and Argentina. This zero-calorie sweetener is 200 times sweeter than sugar. Though it was banned in the US in 1991, the FDA declared stevia GRAS and allowed its use in mainstream US food production in 2008.
While most people tolerate stevia well, some may develop side effects. These include gastrointestinal issues, kidney damage, allergy, low blood sugar, low blood pressure, endocrine disruption, and numbness in hands and feet.
Some studies have also shown that stevia can have beneficial effects on health. It can help in weight loss, reduce the risk of cancer, is helpful to people with diabetes, improves cholesterol levels, and lowers blood sugar and blood pressure.