Stevia a “Sweeter” Alternative to Sugar for Planet Health

A new study from the University of Surrey finds that sweeteners derived from stevia produce ~10% of the greenhouse gas emissions of sugar. The research is published in The International Journal of Life Cycle Assessment.

Plenty of research on safety, but not on sustainability

Many consumers are opting to swap a spoonful of sugar with a non-nutritive sweetener (NNS) alternative, with the aim of reducing sugar consumption and improving health.

Sometimes called “artificial sweeteners”, NNS can be chemically or naturally produced. US Food and Drug Administration (FDA)-approved chemical NNSs include acesulfame potassium, neotame, saccharin, sucralose and aspartame. Steviol glycosides (more commonly referred to as “stevia”) and luo han guo are naturally produced FDA-approved NNSs, extracted from the leaves of the Stevia rebaudiana plant and crushing Siraitia grosvenorii (monkfruit), respectively. NNS are much sweeter than sugar – 4 g of steviol glycosides provides a level of sweetness equivalent to 1,000 g of sugar, for example.

To be approved for human consumption, NNS must undergo long- and short-term safety evaluations reviewing carcinogenicity and toxicity. Since their widespread adoption across the globe, research exploring their impact on the human body has been probed rigorously. However, their sustainability profiles have been understudied.

Stevia-based sweeteners are more environmentally friendly

Addressing this gap, a team of scientists led by Dr. James Suckling, research fellow at the University of Surrey, conducted a life cycle assessment (LCA) on the production of rebaudioside A 60%, 95% pure (known as RA60 in the study) – a steviol glycoside – extracted from the leaves of Stevia rebaudiana grown in Europe.

“An attributional cradle-to-factory-gate LCA was conducted on growing of stevia leaves and extraction of steviol glycosides in Europe. Primary data were used from a case study supply chain. Results are reported in impact categories from the ReCiPe 2016 (H) method, with focus given to global warming potential, freshwater eutrophication, water consumption and land use,” the authors write.

Suckling and colleagues found that producing steviol glycosides has a reduced environmental impact across a variety of markers from the ReCiPe2016 categories when compared to sugar. Specifically, steviol glycosides produce ~10% of the greenhouse gas emissions that sugar production emits.

“This study showed the impact of producing RA60 from cradle-to-gate; it does not include incorporation of the ingredient into food or beverage products, nor consumption and waste disposal. Such a cradle-to-grave life cycle was outside of the scope of this study. A full life cycle study will also need to incorporate health implications for replacing added sugar with sweeteners within diets,” the authors write, adding that this is an area for future study.

"The use of steviol glycosides and similar natural products could be sweet news for the health of our planet,” says Suckling. “However, our study readily admits that much more work needs to be done to understand the health impacts of steviol glycosides and other non-nutritive sweeteners when consumed as part of a wider diet."

Reference: Suckling J, Morse S, Murphy R, et al. Environmental life cycle assessment of production of the high intensity sweetener steviol glycosides from Stevia rebaudiana leaf grown in Europe: The SWEET project. Int J LCA. 2023. doi: 10.1007/s11367-022-02127-9.

This article is a rework of a press release issued by the University of Surrey. Material has been edited for length and content.