Introduction

Stevia, commonly known as candy leaf, honey leaf, sugar leaf, and many different names worldwide, is a natural sweetener. It is made from the leaves of the plant Stevia rebaudiana Bertoni. 

It is 100-300 times sweeter than table sugar and does not contain any carbohydrates or calories.¹ This means that it does not increase your blood glucose levels upon consumption, which is useful for people with diabetes.

History of stevia use and regulatory approvals

The use of stevia as an alternative to sugar dates back to the 1970s in Japan. It was not until the early 2000s that it was widely accepted and marketed as a sugar substitute. 

Initially, it also faced some regulatory hurdles but gained approval after extensive studies related to its safe consumption.

Regulatory approvals:

1. Joint FAO/World Health Organization (WHO) Expert Committee on Food Additives (JECFA) approved stevia in 2008 and recommended an acceptable daily dose of stevia to be 4 mg/kg of bodyweight per day. These recommendations were reaffirmed in 2016 by JECFA²
2. Food and Drug Administration (FDA) also granted high-purity steviol glycosides (Stevia) Generally Recognized As Safe (GRAS) status in 2008
3. The Food Standards Australia New Zealand (FSANZ) also approved it in 2008
4. The European Food Safety Authority (EFSA) approved stevia in 2011 and declared that it does not lead to cancer, reproductive, or developmental problems
5. Stevia extract in highly pure form has been approved to be used for human consumption in more than 150 countries³

Details of different FDA approved artificial and natural sweeteners used in daily use products have been given in Table 1.

Table 1: FDA approved acceptable daily intake of sweeteners.^2,4

How did the use of stevia come under surveillance?

Despite being approved by major food regulatory authorities, some health advocates question its safety for long-term, everyday consumption. This public perception started with media reports stating that the use of artificial sweeteners is related to weight gain, headaches, heart disease, and negative effects on the liver and kidneys.⁵

Further reports stated the long-term consumption of aspartame (an FDA approved artificial sweetener used most commonly in food and drinks e.g. diet sodas) is associated with increased cancer risk in humans.⁶ 

Although the research findings related to the use of these artificial sweeteners have been varying and contradicting, the use of stevia has also come under surveillance.

However, we should remember that stevia is a natural sweetener. The media often fails to highlight the difference between artificial and natural sweeteners. Whilst stevia needs to be processed and purified for human consumption, most research has not shown any adverse effects of long-term stevia use on human health.

Is stevia beneficial for health?

Numerous scientific publications have reported the health benefits of stevia use.

Some research articles have reported that stevia has anti-cancer properties, prevents dental caries, and works as an antioxidant.^7,8

Obesity 

Excessive intake of sugar-rich foods is usually associated with weight gain in adults and children. 

A sugar substitute like stevia can decrease total calorie intake and help manage weight gain.¹⁰

Studies in rat models have shown impressive results, such as a reduction in weight and total cholesterol when stevia was added to their diet.⁹ However, these benefits are inconclusive in humans.¹¹

Diabetes 

People with diabetes have increased blood glucose levels due to insulin resistance or decreased insulin production. 

Studies in rat models and humans show that stevia use helps to lower blood glucose levels.^12,13

The limited number of participants in these studies often leads to inconclusive results.¹¹ 

Hypertension 

Hypertension is a major risk factor for life-threatening diseases like heart conditions. A recent study based on controlled trials in humans has shown that the use of stevia decreases systolic blood pressure.¹⁴

Phenylketonuria

Use of stevia is also safe for patients with phenylketonuria (PKU, a rare genetic disorder that prevents the metabolism of phenylalanine and can cause serious developmental problems). 

People with PKU cannot consume artificial sweeteners like aspartame as it is converted into phenylalanine. A build-up of this amino acid can cause illness for those with the condition.¹⁵

Therefore, using stevia as a sweetener could make meals more enjoyable for people with PKU.

Are there any side effects of stevia use?

Allergic reaction 

Some reports have shown that crude stevia extracts (before they have been purified) have high allergic potential. 

Crude extracts may contain some common allergic substances of Asteraceae family plants (e.g. lettuce, sunflower). These allergic reactions are extremely rare, but their occurrence cannot be ruled out.¹⁶ 

Additionally, the FDA has only approved high-purity stevia extracts and care should be taken to check the ingredient list before buying any product with stevia.

Gut health

Articles have claimed some digestive tract issues are caused by excessive stevia consumption. There is a lack of substantial proof that stevia harms overall gut health. 

Steviol glycosides (compounds responsible for the sweetness of stevia) are not absorbed by the small intestine but are utilised by the gut microbiota. Some reports suggest that stevia also has antimicrobial properties. However, the evidence is limited on how it may impact the microbiome in our gut.⁴

Blood pressure

As stevia lowers your blood glucose levels and blood pressure, people with diabetes or hypertension who are on medication should consult their physicians before switching to stevia use. Excessive stevia consumption, if not regulated properly, can increase the risk of hypoglycemia or low blood pressure.

Taste

Stevia has a distinctive taste and a bitter aftertaste. It can be an acquired taste for many people, but some may not like it at all. Its suitability as a sugar substitute depends on individual taste.

FAQs

Is it safe to take stevia every day?

Yes, stevia can be taken within recommended limits (4 mg/kg of body weight per day). For example, someone who weighs 80 kg would have a recommended limit of 320 mg of stevia per day.

Is stevia safer than artificial sweeteners?

The side effects of artificial sweeteners are controversial but the scientific data in general suggest some adverse health effects with long-term consumption of these products. In light of this, stevia is a relatively safer choice for people who are looking for natural alternatives.

How long does stevia stay in your body? 

Stevia is not absorbed by the small intestine but is metabolised by gut microbiota. It is then absorbed into the bloodstream. It is metabolised and eliminated by the body within 48-72 hours.

What is the healthiest sugar substitute?

Any sugar additives should be used within recommended limits only and their long-term use should be considered carefully. Considering scientific evidence, stevia is a safer and better choice for people who are looking for natural alternatives.

Is stevia still banned in Europe?

Highly purified forms of stevia are not banned in Europe. Crude forms are banned due to inconclusive evidence related to their safety for human consumption.

Does all stevia contain erythritol?

No, not all stevia contains erythritol. The addition of erythritol improves the taste and texture of the sweetener, reducing the bitter aftertaste. Some products contain 100% stevia or pure stevia. Always check the ingredient list on the back before buying stevia products.

Is stevia cancerogenic?

No, studies have shown that it’s not carcinogenic.

Is stevia bad for gut health?

There is no profound proof that it is bad for gut health. Some research shows beneficial effects of stevia use on the gut microbiome, but the overall evidence is limited.

Summary

In conclusion, the comprehensive information collected from available scientific literature as well as by food regulatory authorities suggests no potential side effects of stevia (highly purified form). 

Use of high-purity stevia has shown no adverse effects on the reproductive system and has no mutagenic effects or allergic reactions. It has potential benefits in oral health, patients with diabetes and hypertension, and as a sugar additive in the food, beverage, and pharmaceutical industry.^3,7 

Stevia is still a relatively new product. Research should be done into long-term effects of stevia use in the general population. Irrespective of it being a natural sweetener and safe for human consumption, it should only be consumed within recommended limits.