Refined sugar is incredibly harmful.
For this reason, people are looking for healthy alternatives.
There are many low-calorie sweeteners on the market, but most of them are artificial.
However, there are a few natural sweeteners out there that taste just as good.
One of these is stevia, a sweetener that has become immensely popular in recent years.
Stevia is a 100% natural, zero calorie sweetener with a number of health benefits that have been confirmed in human studies.
What Is Stevia?
Stevia is a green, leafy plant that is native to South America.
It has been used for medicinal purposes for many centuries. The plant has also been bred for its strong, sweet flavor and used as a sweetener.
However, the refined stevia sweeteners used today often don't resemble the whole stevia plant at all.
You can buy whole or crushed stevia leaves, but most often you are getting an extract (either liquid or powder), or a refined version of the plant's isolated sweet compounds.
The two major sweet compounds that are isolated from the leaves are called Stevioside and Rebaudioside A. These two compounds are hundreds of times sweeter than sugar.
Here is an important point... most of the studies use stevioside, the isolated sweet compound. It would be hard to reach pharmacologically active doses of stevioside just by using stevia as a sweetener. It is only about 10% stevioside, by weight.
People often confuse stevia with another sweetener called Truvia, but they are not the same. Truvia is a blend of compounds, one of which is extracted from stevia leaves.
Bottom line: Stevia is a naturally occurring, zero-calorie sweetener. The two major sweet compounds in it are called Stevioside and Rebaudioside A.
Studies Show That Stevia Can Lower Blood Pressure
Elevated blood pressure is a major risk factor for many serious diseases.
This includes heart disease, stroke and kidney failure.
Studies have shown that taking stevioside (one of the sweet compounds in stevia) as a supplement can reduce blood pressure.
One of these studies was a randomized, double-blind, placebo-controlled trial in 174 Chinese patients ().
In this study, patients took either 500 mg of stevioside or placebo (dummy pill), 3 times per day.
These were the results after two years in the group taking stevioside:
- Systolic blood pressure: went from 150 to 140 mmHg
- Diastolic blood pressure: went from 95 down to 89 mmHg
In this study, the stevioside group also had a lower risk of , an enlarging of the heart that can be caused by elevated blood pressure. The stevioside group also had improved quality of life.
There are also other studies in both humans and animals showing that stevioside can lower blood pressure (, , ).
The mechanism is not well understood, but some researchers have suggested that stevioside may act by blocking calcium ion channels in cell membranes, a mechanism similar to some blood pressure lowering drugs ().
Keep in mind that it would be hard to reach these large daily doses with regular use, so just sweetening things with a little stevia here and there probably won't have such a potent blood pressure lowering effect.
Bottom line: Studies suggest that stevioside, one of the sweet compounds in stevia, can lower blood pressure when it is unnaturally high. However, these studies used very large doses.
Stevia May Lower Blood Sugar Levels and Help Fight Diabetes
Type II diabetes is currently one of the biggest health problems in the world.
It is characterized by elevated blood sugar in the context of insulin resistance or an inability to produce insulin.
Stevia has been studied in diabetic patients with impressive results.
In one of the studies, type 2 diabetic patients took either 1 gram of stevioside with a meal, or 1 gram of maize starch.
The group taking stevioside had a reduction in blood sugar by about 18% ().
Another study compared sucrose (regular sugar), aspartame and stevia. It found that stevia lowered both blood sugar and insulin levels after a meal, compared to the other two sweeteners ().
Other studies in animals and test tubes have shown that stevioside may increase production of insulin, as well as make the cells more sensitive to its effects (, ).
Insulin is the hormone that drives blood sugar into cells, so this appears to be the mechanism behind the blood sugar lowering effects.
Bottom line: Stevioside appears to improve function of the hormone insulin, helping to lower blood sugar levels. This may be useful for people with type 2 diabetes.
Other Health Benefits
Stevia has also been tested in animals.
One animal study found that stevioside decreased oxidized LDL cholesterol, indicating that it may help prevent heart disease ().
Stevia has also been shown to have anti-inflammatory, anti-cancer, diuretic and immunomodulatory effects ().
But definitely take all of this with a grain of salt. What works in rats doesn't always work in humans.
Bottom line: The active compounds in stevia have led to numerous health benefits in animal studies, including reduced oxidized LDL cholesterol.
Is Stevia Safe?
Judging from two review studies published in 2010, stevia has not been shown to lead to any adverse effect on health (, ).
However, there have been some claims out there about it having a similar structure to hormones that can interfere with fertility.
Those claims are based on studies on animals that were given extremely high doses, so it is unlikely that this is applicable to humans (, , ).
Bottom line: Overall, stevia has an outstanding safety profile and no adverse effects have been reported in the human studies.
Different Types of Stevia Sweeteners
There are many different types of stevia. The problem is that some of them taste bad.
Therefore, getting the right kind is absolutely essential.
You can buy stevia in powder and liquid form. Some people prefer the powder over liquid and claim that it has less aftertaste.
Note that the liquid forms often have alcohol added to them, which might contribute to the bad taste.
Look for a brand that is organic, has no unnatural additives and has good flavor according to reviews.
How to Use It
Stevia can be used in many ways.
You can add it to your smoothie, yogurt, tea, coffee and other beverages. It is also a good sugar substitute for baking.
Since you can buy it in liquid and powder form, it's more convenient to use the liquid form for beverages and the powder for baking.
When it comes to baking with stevia, many people mix it with erythritol, another natural low-calorie sweetener that is much bulkier.
When using it in recipes, keep in mind that it is incredibly potent.
1 teaspoon of stevia extract can have a similar sweetening power as a whole cup of sugar, but this can vary between brands.
Take Home Message
Stevia is perhaps the only sweetener that is not just "not harmful," but has actual health benefits.
It has no calories, is 100% natural, and if you choose the the right one then it also tastes like a million bucks.
I hereby declare stevia the king of sweeteners.