The diet industry is a mega-billion dollar enterprise, and everyone is always on the lookout for the perfect sweetener that tastes great and has no calories. Unfortunately, many (or all) of the chemical sugar substitutes have notorious (and controversial) adverse health effects. But one sugar alternative is naturally calorie-free and has been in use for centuries - Stevia.
"Stevia" is a plant genus of about 240 species of herbs and shrubs
native to South America, Central America, and Mexico, with several
species reaching as far north as Arizona, New Mexico, and Texas.
But when most people refer "stevia", they mean the species Stevia
rebaudiana, which is also known as "sweetleaf" or "sugarleaf".
Compared to sugar, stevia's taste is sweeter, has a slower onset and
longer duration, and may have a bitter aftertaste.
The Guarani tribes of Paraguay, Bolivia, and Brazil have used stevia
leaves (which are 30-45 times sweeter than sugar in their natural form)
as a sweetener and medical herb for centuries. In 1899 the use was
documented as Swiss botanist Moises Santiago Bertoni described the plant
and its use in his research in eastern Paraguay. It wasn't until
1931 that the glycosides that give stevia its sweet taste were isolated
by French chemists. The compounds were named stevioside and
rebaudioside - in their pure forms they are 250-300 times sweeter than
sugar, heat stable, pH stable, and non-fermentable.
In the early 1970s, Japan implemented the use of stevia as an
alternative to the artificial sweeteners that have been considered
health risks and possible carcinogens, such as aspartame and saccharine.
The population of Japan currently consumes more stevia than any other
country, and stevia holds 40% of their total sweetener market.
Now, stevia is cultivated and used in food throughout many parts of
Asia, including China, Korea, Taiwan, Thailand, and Malaysia.
The U.S. banned stevia in the early 1990s (unless labeled as a
supplement). The ban was supposedly over health concerns, but many
believe it was actually due to political controversies and the power and
lobbying of the artificial sweetener industry. In 2008, the FDA
approved the rebaudioside-A extract of stevia as a food additive.
Rebaudioside-A has the least bitterness of the stevia extracts.
The produce it commercially, stevia plants are dried then subjected to a
water extraction process. The resulting crude extract is about 50%
rebaudioside-A, which is then refined again using ethanol, methanol
crystallization, and other patented technologies to separate molecules
and isolate pure rebaudioside-A. (Quite a process to refine and
make "safe" what people have used in whole natural form for centuries
with no ill-effects..) Similarly, the National Research Council of
Canada has patented refinement processes using a series of
nanofiltration and microfiltration and ultrafiltration and other
vaguely-scientific sounding procedures. Rumor has it that
requiring such extensive patented refinements are for the benefit and
appeasement of industry, since as a naturally-occurring substance no
patent is required to produce stevia, so anyone can do it.
Despite having been used by tribes in South America for centuries in
natural form, and by millions of people for decades in Japan in refined
form, all with no apparent ill-effects, many are still concerned of the
health risks of using stevia. They refer to a 1985 study that
reported that steviol (a breakdown product from stevioside and
rebaudioside) is a mutagen in the presence of liver extract of rats.
But this study, in addition to being quite tangential to human use of
stevia, was criticized on procedural grounds and for mishandling of data
such that even distilled water would have appeared mutagenic. The
bulk of subsequent studies have shown no such harmful effects. No
studies have shown genotoxicity for rebaudioside-A, and there has been
no evidence that any constituents of stevia cause cancer or birth
defects.
In fact, recent medical research has shown stevia is a promising
treatment for obesity, type-2 diabetes, and hypertension. Some
studies have shown stevia to improve insulin sensitivity in rats and
maybe even promote additional insulin production, giving some hope that
stevia can help reverse diabetes and metabolic syndrome.
Adiditonally, some preliminary human studies suggest stevia may help
reduce hypertension. In 2006, the World Health Organization, after
a thorough evaluation of recent studies in both animals and humans,
concluded that stevioside and rebaudioside-A are not genotoxic or
carcinogenic, and have corroborated the evidence of pharmacological
effects in treating hypertension and type-2 diabetes. But much
more research is needed. Stevia has been suggested as a possible
treatment for osteoporosis due to the claims that adding a small amount
of stevia leaf powder to chicken feed reduced eggshell breakage by 75%,
and pigs fed stevia extract have twice as much calcium in their meat.
Although many stevia sweeteners are entering the market under various
names and with various additives, the two most commonly-found namebrand commercial stevia sweeteners are Truvia
(produced by a joint venture between Coca-Cola and Cargill) and Sun
Crystals (produced by McNeil Nutritionals, LLC, a subsidiary of Johnson
& Johnson). Truvia is made from rebiana (stevia extract) and
erythritol (found in some fruits, mushrooms, and fermented foods) which
is added to provide bulk and texture.
Sun Crystals claims to be the most natural of the commercial stevia
sweeteners, as it contains only stevia extract and cane sugar. The
cane sugar adds a few calories, but takes the edge off the bitterness
and provides texture and the other baking properties and "good stuff" we
get from sugar, such as moisture, caramelizing, and preservative
properties.
The rough recipe conversion rate for sugar to stevia sweeteners is 2:1
(if your recipe calls for 1 cup of sugar, use 1/2 cup of stevia
sweetener), but check the actual conversion rates for the brand you're
using.
 |
|
|
|
|
|
|
*The Fine Print
