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The surprising health benefits of stevia sweeteners

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The dangers of consuming too much sugar are well known, but there are a number of sweet alternatives like stevia to consider.

We consumers are a demanding bunch. We want to enjoy sweet treats but without the adverse health effects of consuming too much sugar: weight gain, rotten teeth, spikes in blood sugar. We’re not keen on low-calorie artificial sweeteners such as aspartame that, although deemed safe for consumption, have had negative press over the years. According to recent research, they may cause changes to the way the body processes fat and energy, promoting metabolic dysfunction. We would prefer more “natural” plant-based sweeteners. Oh, and please could the products they are used in taste as good as the full-sugar version?

No wonder, then, that the food and beverage industry is on a quest to develop a new generation of sweeteners to replace sugar on supermarket shelves. In the future, we may be consuming products flavoured with the so-called African “miracle berry” Synsepalum dulcificum, which contains a molecule that binds to receptors on the tongue, making sour foods taste sweeter. An extract of Chinese monk fruit is currently creating a lot of interest, and a plant-based product called Cweet has been developed that is 2000 times sweeter than cane sugar.

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However, the clear winner in the sweetness stakes right now is stevia. Made up of glycosides extracted and refined from the leaves of stevia rebaudiana, it is hardly new on the scene. The leaves of this shrub have been used in South America for hundreds of years but it has taken decades to isolate the various compounds, test them for safety and create the sweetness we are after.

Coral Colyer, the scientific and regulatory affairs manager for Coca-Cola South Pacific, says mimicking sugar is a complex business. “It’s not just replacing the sweetness,” she explains. “Sugar does a lot of other things in foods. One of the first that you notice is the impact it has on mouthfeel.”

The texture that sugar gives to a product, the way it coats your mouth and even the delivery of sweetness, is difficult to replicate.

“When you’re consuming sugar, the intensity will peak at a certain height, last a certain period of time and then decline,” explains Colyer. Alternative sweeteners have differing peak points and aftertastes. They may not dissolve or blend as easily as sugar, or be as stable in hot temperatures and different levels of acidity.

Coral Colyer.

Some people actually experience stevia as bitter. When Coca-Cola began considering it as a low-calorie alternative for its sparkling drinks and fruit juices, it was necessary to use various glycosides extracted from the plant, all with differing taste profiles, to create a blend that hit the sweet spot. This year, New Zealand was the first country in the world to experience the result, Coca-Cola Stevia No Sugar.

You will find stevia extract in reduced-sugar products such as Wattie’s tomato sauce and baked beans, and Vogel’s cereals. It is also used in jams, ice cream, cakes and yogurts.

It has no calories, won’t spike your blood sugar and is believed to be tooth-friendly. And it is hugely popular in Japan, where it has been used for decades. But is stevia safe?

The US Food and Drug Administration hasn’t approved the leaf or crude extracts as a food product, but it does consider high-purity stevia glycosides to be safe for consumption.

There even appear to be health benefits. Stevia can help control blood sugar in people with diabetes and seems beneficial for the circulatory system and kidneys – it acts as a diuretic. It is also known to act as a vasodilator, causing blood vessels to widen, lowering blood pressure. So far, only the positive effects have been studied; people with chronic low blood pressure may want to think twice about consuming lots of it.

Colyer says there is clear consumer demand for healthier products. “About a third of our sales in New Zealand are in low- and no-kilojoule options. We’ve been watching the category over the past 10 years and it’s been expanding rapidly.”

It took Coca-Cola nearly a decade to develop a 100% stevia beverage they believe delivers on taste. For that sort of investment, companies have to be confident that by the time they have finished, people will still want to buy the product.

Colyer is convinced that with stevia they are onto a winner. “Health is not a fad,” she says.

This article was first published in the August 18, 2018 issue of the New Zealand Listener.