People are looking for healthy alternatives to sugar. 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.
The most popular of these is stevia, a sweetener that has become immensely popular in recent years.
Stevia is a 100 percent 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 stevia leaves are called Stevioside and Rebaudioside A.
These two compounds are hundreds of times sweeter than sugar. Stevioside has more of an aftertaste than Rebaudioside.
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. Stevia is about 10 percent 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 stevia 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 stevia’s sweet compounds) as a supplement can reduce blood pressure.
One of these studies was a randomized, double-blind, placebo-controlled trial in 174 Chinese patients (1).
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.
There are also other studies in both humans and animals showing that stevioside can lower blood pressure (2, 3, 4.)
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 (5).
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 percent (6).
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 (7).
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 (8, 9).
Insulin is the hormone that drives blood sugar into cells, so this appears to be the mechanism behind stevia’s 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.
Stevia Has Shown Health benefits in a Number of Animal Studies
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 (10).
Stevia has also been shown to have anti-inflammatory, anti-cancer, diuretic and immunomodulatory effects (11).
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?
Until 2008, stevia was banned as a food additive in the US.
After some pressure from the food industry, the FDA changed their stance and allowed the sweet compounds from stevia to be used in foods (12).
Judging from two review studies published in 2010, stevia and the two major sweet compounds in stevia (stevioside and rebaudioside) have not been shown to lead to any sort of adverse effect on health (13, 14).
However, there have been some claims out there about stevia having a similar structure to hormones that can interfere with fertility.
Those claims are based on animal studies and the animals were given extremely high doses of stevia extract, so it is unlikely that this is applicable to humans (15, 16, 17).
Bottom line: Overall, stevia has an outstanding safety profile and no adverse effects have been reported in the human studies.
Which Stevia Should You Buy?
There are many different types of stevia. The problem is that some of them taste bad.
Therefore, getting the right kind of stevia 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 types of stevia often have alcohol added to them, which might contribute to the bad taste.
Keep in mind that manufacturers often add other ingredients to their stevia-based products, so make sure to read the ingredients list!
Bottom line: You can buy stevia in liquid and powder form, some say that the powder has less aftertaste. Keep in mind that other food additives are often mixed with stevia, so make sure to read the label carefully.
How to Use Stevia
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 stevia 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 stevia in recipes, keep in mind that about 1/2-1 teaspoon of stevia extract is claimed to have equivalent sweetening power to 1 cup of sugar.
Kris Gunnars represents AuthorityNutrition.com – a site that helps people make informed decisions about their health based on the best scientific evidence available.