Most people have a love/hate relationship with it.
Sugar is arguably the world’s favourite ingredient to make food that tastes incredible and makes you feel good.
Unfortunately, it has a massive downside.
As the obesity epidemic and the low-fat fad gained popularity, food manufacturers started replacing fat in the food with sugar.
Now that the low-fat nonsense has been exposed and calories have become the leader of the show, people are turning to sugar.
With 4 calories per gram and the fact that you can find sugar in soft drinks and almost any type of processed food, it has become a major part of the calorie intake of western nations.
Naturally, people have looked for a substance that has all the qualities of natural sugar (mainly the taste), but none of the downsides (the calories.. and carbs).
So far, the development of these products hasn’t had any effect on the obesity epidemic and the evidence in their favour is not convincing.
Stevia – A Natural, Low-Calorie Sweetener
Stevia, or more specifically Stevia Rebaudiana, is a plant that grows naturally in South America.
The leaves of the plant contain various compounds, but the two active ones are called Stevioside and Rebaudioside.
These molecules contain structures that are very similar to glucose, similar enough that the taste receptors on the tounge bind them and recognize them as sweet.
These compounds are up to 300-450 times sweeter than table sugar. Their caloric value is effectively zero.
When you buy a product sweetened with Stevia, you’re not really buying an extract of the whole plant. You are actually buying a purified sample of some of its compounds.
The level of purity will depend on the brand. Some of the commercial Stevia sweeteners only contain the active ingredients Stevioside or Rebaudioside.
Is Stevia Good For You? A Look at The Health Benefits
There have been multiple studies on Stevia, but mostly in rats. In rats, Stevia has been found to have anti-hyperglycemic, anti-hypertensive, anti-inflammatory, anti-tumor, anti-diarrheal, diuretic, and immunomodulatory effects (3).
Take that with a grain of salt as that doesn’t necessarily translate to humans.
Here I’m going to stick to human beings, but Stevia has some evidence of health benefits in controlled human trials.
Stevia and Glycemic Control in Diabetics
Stevia has shown promise in improving glycemic control in diabetics and is often recommended for this purpose.
A study in 12 type II diabetics compared ingesting 1g of Stevioside (one of the sweet compounds in Stevia) vs. 1g of starch, 30 minutes before a meal. Blood glucose levels were measured and tended to be lower in the Stevioside group, by an average of 18%.
Another study of 12 lean and 19 obese individuals of the ages 18-50 compared consumption of either Stevia, Aspartame or Sucrose before a test meal. Stevia reduced glucose and insulin levels after the meal compared to both Aspartame and Sucrose (5).
Stevia and High Blood Pressure
A two-year, randomized controlled trial of 168 Chinese men and women with mild essential hypertension (elevated blood pressure) took either 500mg of Stevioside or placebo, three times per day.
The Stevioside group reduced their systolic blood pressure from 150mmHg to 140mmHg and their diastolic blood pressure from 95mmHg to 89mmHg.
The Stevioside group also had improved quality of life and a much lower risk of developing left ventricular hypertrophy, which is a thickening of the left part of the heart, a common consequence of chronically elevated blood pressure (6).
Another randomized trial, with 106 Chinese men taking 250mg of Stevioside (or placebo) three times per day discovered that the Stevioside group lowered their blood pressure from 166 to 152.6 (systolic) and from 104.7 to 90.3 (diastolic) (7).
Another study didn’t find any effect of Stevioside on blood pressure compared to placebo.
Yet another study in humans found that Stevioside 250mg, three times per day, had no effect on blood pressure or glycemic control compared to placebo in normal, hypotensive (low blood pressure), type I and type II diabetics (8).
Is Stevia Safe?
Stevia, despite being a subject of political controversy quite a few years ago, has an outstanding safety profile.
There is a possibility that Stevia improves glycemic control in diabetics, as well as high blood pressure, but the results of the studies are conflicting.
I find it unlikely that people using a bit of Stevia in their foods would experience such effects, because the dosages in the studies are fairly high.
There doesn’t seem to be anything magical about Stevia from the average persons point of view, but it is probably the safest sweetener out there. It is natural and has been in use for centuries in certain areas of the world.
Whether Stevia will lead to weight gain and disease in the long-term like many of the artificial sweeteners seem to do (in the context of a non-calorie-controlled western diet) has yet to be resolved.