What is the environmental impact of a sugar substitute?

Sugar substitutes like Stevia are generally promoted as a health choice. They are low or no calorie and are often significantly sweeter allowing people to use less. But while the health effects are continually the subject of research, the environmental impacts have been less well studied.

Suckling and colleagues (2023) have attempted to address this gap for one sweetener derived from the Candyleaf or Stevia rebaudiana plant. The plant has been used for generations in Paraguay but has garnered worldwide attention and is now grown across the world as a sweetener. There are different compounds but they generally run 200-300 times sweeter than sugar. As a result, you need 4 g of stevia compared to 1 kg of sugar for the same sweetness.

Before I look at the details, this research was about a specific extract from the plant. Different compounds have different extraction protocols which affect the impacts. Another note is that this study did not include impacts from manufacturing, transport of consumer goods, or consumer side waste. In other words, it covers from growing through processing for use. But the comparison with sugar covers the same period. Finally, this study only compares direct replacement with sugar, which mostly happens in drinks. As you can probably guess, replacing sugar in food products requires additional efforts because of the difference in volume and a few other characteristics of sugar versus stevia.

So how does stevia compare to sugar? For land use, stevia uses almost 90% less land than sugar. In terms of contributions to climate change and global warming, Stevia has 5.7-10.2% of the impact of sugar.

There are lots of other factors involved in the use of non sugar sweeteners. The authors even point out that there could be environmental impact effects from improved health associated with lower sugar consumption. But, this is an interesting and important discussion. We have to get better at looking at the full system associated with changes and this is part of that effort.