Stevia and Blood Sugar: A Sweetness Solution

1. History: Stevia is a plant native to Paraguay and Brazil that has been consumed by humans for thousands of years.
2. Sweetness: Stevia leaves contain sweet molecules that can be extracted and used as a tool in the healthy sweetness toolkit.
3. Blood Glucose: Stevia lowers blood glucose in an adaptogenic way via several mechanisms and is actively therapeutic to those with pre-diabetes and diabetes.

A Long History of Sweetness and Medicine

Did you know that stevia leaves have been consumed by humans for thousands of years for sweetness and for medicinal purposes? Stevia consumption dates to before cane sugar became widespread, as it was used “since time immemorial” by the indigenous peoples’ of Central and South America, according to reports by Swiss botanist Bertoni, and according to the book, ‘Natural History of Plants of The New Spain’, by Spanish physician Francisco Hernandez in 1570-1576. Medicinal practice includes its use as an anti-inflammatory, anti-hypertensive, to promote heart health, and regulate blood glucose.

What exactly is stevia’s impact on blood glucose and metabolic health?

Hundreds of scientific studies have been conducted to understand if and how stevia is health enhancing in various conditions, including the crux of the problem of excess sugar: insulin resistance and high blood glucose.

Numerous animal and human studies indicate that stevia lowers blood glucose and improves insulin sensitivity in the context of carbohydrates and high blood glucose. In a ‘normal’ insulin sensitivity and blood glucose context, it does not lower blood glucose too far either – it acts as an adaptogen. Below is a summary of a handful of the many studies exploring if and how stevia works to regulate blood glucose.

Healthy Humans

A human study by Curi R. et al. (1986) gave an aqueous stevia extract to 16 healthy participants at regular intervals of 5g (20g/day) over 3 days. When performing oral glucose tolerance tests (OGTT) in which participants were given 100g of a glucose drink and their blood glucose was measured over six time intervals, plasma glucose levels after stevia treatment were significantly lower than the control group at every time point (including basal, fasting blood glucose) (p<0.01 and p<0.05).

Curi R. et al. (1986): blood glucose curve after oral glucose tolerance test in group who have not received stevia (black dots), vs. those who have received stevia treatment (circles).

Is this amount of stevia leaf extract relevant to us? Yes. A typical stevia-sweetened 330ml drink contains c. 130mg of steviol glycosides, and based on this study’s methodology, it is likely that the 5g infusion doses equated to 520mg of steviol glycosides. Thus, if one were to have several stevia sweetened drinks or snacks in a day, one could achieve a similar level.

Philippaert K. et al. (2017) observed that in a high glucose context, stevia promotes insulin secretion by pancreatic beta cells, whereas in a normal glucose context, it does not, acting in an adaptogenic way. They also found that daily consumption of stevia in animals eating a diabetes-inducing high fat diet prevented diabetic hyperglycemia.

Philippaert K. et al. (2017): glycemia area under the curve in control mice (circles) vs. mice treated with stevioside (black dots).

Humans with Type II Diabetes (T2D)

In Gregersen et al. (2004)’s paired cross-over study, compared to the control, patients given 1g of steviol glycosides (stevioside), with a standard test meal, had significantly 18% lower incremental area under the curve (iAUC) blood glucose (p = 0.013). In a remarkable double-blind placebo-controlled trial in 55 humans with T2D, patients stopped their blood glucose lowering mediations and instead took 1.5g/day of stevioside for 3 months.

Both HbA1c (a biomarker for mid-term blood glucose levels) and fasting blood glucose significantly increased in the placebo group (p<0.01 and p<0.007 respectively) during the 3 months, whereas the stevioside group saw no change in these biomarkers compared to when patients were on their blood glucose lowering medications. This points to the potential for stevia to be used as a blood glucose regulating medication itself.

So, How does Stevia have this therapeutic action of helping to lower blood glucose in the right context?

See below for a reminder of the key root causes of high blood glucose, and how stevia ameliorates all three of these. Mechanisms of Action: How Stevia works to Improve Blood Glucose Regulation.

How Stevia Lowers Blood Glucose

Enhances insulin sensitivity, glucose uptake + conversion to glycogen
in muscle cells

Suppresses gluconeogenesis (glucose production by liver) by suppressing glucagon


Improves pancreatic beta cell function to modulate insulin
response to carbohydrate

What Makes Blood Glucose Too High?

Insuline Resistance:
Cells are not responding to insulin and taking up glucose.
Early signs of this = in muscle cells.

Liver Gluconeogenesis: Liver keeps pumping out glucose


Pancreatic beta cell dysfunction exacerbating insulin resistance and then failing to produce sufficient insulin.

Conclusion

Excess sugar drives insulin resistance and metabolic disease. Nature has provided various forms of sweetness that are not sugar (not sucrose/fructose). In the case of stevia – nature has provided sweetness that helps to ameliorate the very disease caused by excess sugar, still the predominant sweetener used by humans. It is time we take the hint and transform sweet food and drink products into health promoting ones instead of sugar-saturated health undermining ones.

Stevia is not a 1:1 replacement for sugar however – one needs to know how to use it in the healthy sweetness toolkit to create great-tasting food and beverage products. If you would like help to formulate your product with healthy sweetness, email:

customerservice@nutriba.com

References
Curi, R. et al. (1986), ‘Effect of Stevia rebaudiana on glucose tolerance in normal adult humans’, Braz J Med Biol Res. 19(6):771-4.
Philippaert, K. et al. (2017), ‘Steviol glycosides enhance pancreatic beta-cell function and taste sensation by potentiation of TRPM5 channel activity’, Nat Commun 8, 14733.
Gregersen, S. et al (2004), ‘Antihyperglycemic effects of stevioside in type 2 diabetic subjects’, Metabolism. 2004 Jan;53(1):73-6.
Jeppesen, PB. et al. (2006), 'Efficacy and tolerability of oral stevioside in patients with type 2 diabetes: a long-term, randomized, double-blinded, placebo-controlled study', Diabetologia 49 (Suppl 1) AO843.