Have you heard some pros and cons about stevia and wondered whether it’s a good natural sugar substitute?
In my usual fashion I went on a search through some of the latest research to bring you a few of the facts.
What is Stevia?
Stevia is a herb from South America that has been used for centuries.
Today it comes in both powder and liquid form and can be used in cakes, bakes, and anything you want to add sweetness to. It is 250 times sweeter than sucrose and the active components are steviol glycosides, rebaudioside A and stevioside.
It’s been used for the longest period of time in the Japanese food suppy after saccharin was banned but can now be found throughout the world.
Something most people aren’t aware of is that there is white stevia and green leaf stevia. The white powder is chemically processed, you only have to ask yourself why it’s pure white when it comes from a plant with a green leaf. Still, it is the most commonly consumed type of stevia because it’s readily available and easy to use. You can get green leaf stevia but it’s not as sweet.
It’s true that stevia is low GI, contains no calories and has been attributed in some studies to aiding the pancreas and improving digestion. Liquid stevia extract is often a better choice because it’s less processed. You can also get flavoured stevia liquids, like vanilla and so forth. I guess it just depends on preference and how you are going to use it.
In many of the recent studies that have been done stevia is considered safe (1).
Can Stevia Cause Cancer?
Question from Kathryn: Stevia has been linked to cancer in some studies. Do you consider it safe?
I looked at a few studies and position statements and this is what I found.
The US National Cancer Institute says there is no clear evidence to suggest that stevia is linked to cancer (2). A long term study in 344 rats given a diet with 5% stevia intake did not show any signs of cancer after 108 weeks of ingestion (3).
In one recent study 36 derivatives of stevosides from stevia were put to the test on leukemia, lung, stomach and breast cancer cell lines. The study showed that the stevosides “exhibit potent cytotoxicity against the cancer cell lines” (4). Cytotoxicity means the compound is toxic to cells. “Treating cells with the cytotoxic compound can result in a variety of cell fates. The cells may undergo necrosis, in which they lose membrane integrity and die rapidly as a result of cell lysis. The cells can stop actively growing and dividing (a decrease in cell viability), or the cells can activate a genetic program of controlled cell death”. Source
So what this means is that this recent study has shown that stevia may cause cancer cell death, not contribute to cancer. That’s the most recent study I could find Kathryn, so I hope that helps and I certainly find it convincing enough.
Does Stevia Have Toxic Effects?
Question from Beth: I’ve heard that stevia can be toxic, is this true?
When you eat stevia it passes directly through the upper intestine, but in the lower intestinal tract stevioside gets metabolised by intestinal flora into steviol. Studies show that after ingestion there is no free steviol found in the blood but only some left in feces (that’s your poop) (3).
Some studies have reviewed the genotoxic effect of stevia, meaning how it might affect our DNA and cells. Out of 16 studies reviewed only 2 reported possible genotoxic effects. One of the studies was conducted on rats given extremely high doses with the outcome being DNA breakage in various cells in the body. This is the only study that has ever reported these results so the evidence is inconclusive, especially when most of the studies report otherwise. It is also highly unlikely that we would ever eat the amount of stevia given to the rats in this study (3).
I guess that really means that no toxic effects have been found as of yet.
Effects of Stevia on Food Intake, Blood Sugar and Insulin
When stevia was compared with sugar it has been shown to regulate appetite with less food being consumed throughout the day as opposed to sugar. This is great because it means with stevia you are not going to compensate with extra food intake, which you normally would with eating more sugar.
Stevia causes no glycemic response and has also been shown to reduce blood sugar levels at 20 and 30 minutes post meal compared to sugar. When stevia was compared to both sugar and aspartame for post meal insulin levels they were also significantly reduced. And on top of that, stevia has been shown to increase insulin sensitivity (5).
What this means is that stevia is a good alternative for people with insulin resistance, diabetes, high blood sugar, and perhaps for things like hypertension and heart disease.
Is Stevia The Best Natural Sweetener?
Question from Rachel: I have Stevia, is that the best thing to have?
One study showed that using stevia in foods did not change the composition of the food or its nutrient profile in any way, meaning all the vitamins and minerals stay at the same levels (6).
So let’s break it down the pros and cons of stevia:
- Stevia has no calories – good
- Stevia does not cause cancer – good
- Stevia does not appear to cause toxic effects – good
- Stevia shows a positive influence on food intake, blood sugar and insulin – good
- Stevia doesn’t affect vitamins and minerals in food – good
- Stevia still makes things taste sweet – good
- Stevia may be chemically processed – bad
Considering the evidence and the pros and cons of stevia I think it is a good natural sweetener to use.
I hope this has answered your questions and you find it helpful.
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1. Carakostas MC, Curry LL, Boileau AC, Brusick DJ. Overview: The history, technical function and safety of rebaudioside A, a naturally occurring steviol glycoside, for use in food and beverages. Food and Chemical Toxicology. 2008; 46: S1–S10.
2. Academy of Nutrition and Dietetics. Journal of Academy of Nutrition and Dietetics. 2012: 2212-2672.
3. Brusick DJ. A critical review of the genetic toxicity of steviol and steviol glycosides. Food and Chemical Toxicology. 2008; 46: S83–S91.
4. Ukiya M, Sawada S, Kikuchi T, Kushi Y, Fukatsu M. Akihisa T. Cytotoxic and Apoptosis-Inducing Activities of Steviol and Isosteviol Derivatives against Human Cancer Cell Lines. Chemistry and Biodiversity. 2013; 10: 177-185.
5. Anton SD, Martin CK, Han H, Coulon S, Cefalu WT, Geiselman P, Williamson DA. Effects of stevia, aspartame, and sucrose on food intake, satiety, and postprandial glucose and insulin levels. Appetite. 20120; 55:37–43.
6. Koyer GT. The Low Calorie Sweetener Stevioside: Stability and Interaction with Food Ingredients. Lebensm.-Wiss. u.-Technol. 1999; 32: 509-512.
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