Is stevia healthy? Until recently, I mostly didn't trust the stuff.
Many versions have a bitter aftertaste; the white powdered stevia looks suspiciously unnatural; and though you may disagree with me, I think most people should simply eat some (minimally processed) sugar and stop obsessing over finding a substitute.
Turns out though, that stevia may be a pretty darn good sugar replacement for those who really need or want one – depending and what version you choose and how you plan to use it (not in baked goods since it doesn't provide any mass like sugar).
My first hint to its worthiness was when fresh-cut stevia appeared in my farm box – all green and local – looking nothing like the suspicious white powder that I was accustomed to seeing.
Turns out that stevia grows much like mint, with leaves 30-50 times sweeter than table sugar. Though sometimes challenging to start from seed, as a house or garden plant it's easy to care for. It’s been cultivated and used both as a sweetener for tea and for its medicinal properties for over 1500 years by the Guarani people and for centuries in Paraguay and Brazil.
For diabetics, using stevia may be a good way to manage blood sugar levels while not completely omitting the sweet flavor from your life. Stevia has been used as a sugar substitute since the 1970's in Japan without any known adverse effects, and it constitutes 40% of their total sweetener consumption.
One study showed that not only is stevia a good sugar substitute, but it may actually help to treat insulin resistance. (source)
In another small study, 60 hypertension patients experienced significant reduction in blood pressure after being give the active ingredient of stevia. (source).
Though a study from the 1960's indicated that giving extremely high doses of stevia to rats may cause infertility, subsequent research all shows that stevia does not pose a risk to human fertility, especially in the dosages of normal consumption. This article provides a great summary of the research around stevia and fertility.
In the U.S. stevia was approved as a dietary supplement since 1995. In 2009, the FDA approved rebiana, an active component of stevia, as a food additive at the urging of the likes of Coca Cola (who owns Truvia) and Pepsi (who owns Purevia). Stevia itself is not approved for use in packaged foods.
Not all stevia is the same
In it's processed form, the chemical compounds called “steviosides” – which give stevia it's sweetness – are isolated and extracted.
One of these compounds, called Rebaudioside A (a.k.a. rebiana or Reb A) is the sweetest (250-300 times sweeter sugar) and has the least bitterness. For these reasons it is the compound most used in processed stevia sweeteners.
To extract Reb A/rebiana, stevia plants are dried, extracted with water, and then separated with a secret patented crystallization technique that uses ethanol or methanol. Many companies then use fillers such as dextrose (corn fiber), cellulose, erythritol, isomaltulose and/or the ubiquitious “natural flavors” to create the finished product that ends up on your grocery store shelf or in the sugar caddy at a trendy restaurants.
The secrets and fillers are where my optimism on stevia halts. I don't know about you, but I prefer to stick with the more traditional preparations for food. Though stevia tablets and packets may be super convenient and are not likely to kill you, if you're going to consume this stuff on a regular basis, I suggest going au naturale.
The natural choice: how to use fresh or dried stevia leaves for sweetening
The leaves of the stevia plant are what yield the sweetness. You can use them fresh or dry them by laying them in a single layer on piece of paper in the sun or counter top.
You can sweeten hot tea or coffee by simply dropping a single leaf (fresh and crushed or dried) into the drink.
I've experimented with making stevia “simple syrup” using fresh and dried leaves, water or alcohol, and my favorite method I discovered from my friend Kristen at Food Renegade.com in her post, How to Make Liquid Stevia Extract which uses dried leaves and vodka.
This solution is nice for sweetening hot or cold drinks and would work well in homemade jello, barbeque sauce, or even butter cream frosting.
Get organic stevia leaves here to make your own extract.
What about commercial liquid extracts?
If you don't have the time, energy or interest in tending a stevia plant or making your own extract from dried herbs, the next best option is store bought extract. While this clear liquid extract is said to be extracted without any bleach or chemical whiteners, my guess is that the whole leaf concentrate is the closest to making your own.
All in all, stevia makes a decent sugar substitute, even more so when you choose a natural preparation.
Do you use stevia? Why or why not?