Pure stevia has not been directly linked to strokes in clinical research. In fact, studies on steviol glycosides (the active compounds in stevia) suggest they may slightly lower blood pressure rather than raise it. The real concern comes from what’s often mixed with stevia in commercial products, particularly erythritol, a sugar alcohol that has been tied to increased clotting risk and cardiovascular events in recent studies.
What the Research Says About Stevia Itself
Steviol glycosides, the sweet compounds extracted from the stevia plant, have been studied in randomized clinical trials for their effects on heart health. A systematic review and meta-analysis of these trials found that stevia produced a small, non-significant drop in systolic blood pressure (about 3 mmHg) along with meaningful reductions in diastolic blood pressure and fasting blood glucose. High blood pressure is one of the strongest risk factors for stroke, so a sweetener that trends toward lowering it is, if anything, working in the opposite direction.
Stevia also appears to be neutral when it comes to blood sugar and insulin, two metabolic factors that influence long-term cardiovascular risk. A controlled trial in people with type 2 diabetes found no significant changes in fasting blood sugar, insulin levels, or cholesterol after two months of stevia use. Other research has shown stevia may help lower elevated blood sugar without affecting normal levels. None of this points toward an increased stroke risk from stevia on its own.
The joint expert committee of the WHO and FAO has set stevia’s acceptable daily intake at 0 to 4 mg per kilogram of body weight. For a 150-pound person, that works out to roughly 272 mg of steviol glycosides per day. Most people using stevia in coffee, tea, or cooking stay well within that range.
The Erythritol Problem
Here’s where the confusion starts. Many products labeled “stevia” on store shelves aren’t pure stevia. They’re blends that use erythritol as a bulking agent because steviol glycosides are extremely potent and hard to measure in tiny amounts. Erythritol gives the product volume so you can scoop or pour it like sugar. If you check the ingredients on popular stevia brands, erythritol is often the first item listed, meaning it makes up the majority of the product by weight.
Erythritol has drawn serious concern. A large study tracked cardiovascular events over three years and found that people with the highest blood levels of erythritol were about twice as likely to experience a heart attack or stroke compared to those with the lowest levels. That’s a striking association, though the study was observational, meaning it identified a correlation rather than proving erythritol directly caused those events.
A follow-up study in healthy volunteers tested the mechanism more directly. After consuming 30 grams of erythritol (a typical amount found in erythritol-sweetened foods), participants saw a more than 1,000-fold increase in erythritol plasma concentration. Their blood platelets became significantly more reactive, releasing higher levels of chemicals involved in clot formation. Glucose, by comparison, triggered no such response. Blood clots are the immediate cause of most strokes, so a substance that makes platelets stickier raises a legitimate red flag.
Thirty grams of erythritol is not an extreme dose. A single can of an erythritol-sweetened beverage or a few servings of an erythritol-based stevia blend could approach that amount, depending on the product.
Broader Concerns About Non-Sugar Sweeteners
Stevia falls into a larger category of non-sugar sweeteners that the WHO flagged in 2023. The organization recommended against using any non-sugar sweeteners for weight control or disease prevention, citing evidence of potential long-term risks including increased rates of type 2 diabetes, cardiovascular disease, and mortality. Stevia and stevia derivatives were specifically named alongside aspartame, sucralose, and others.
A large prospective study from France (the NutriNet-Santé cohort) found that higher consumers of artificial sweeteners had a cerebrovascular disease rate of 195 per 100,000 person-years, compared to 150 per 100,000 in non-consumers. That study broke results down by individual sweetener, linking aspartame most strongly to cerebrovascular events and sucralose to coronary heart disease. Stevia was not singled out as a top offender in those specific analyses.
The WHO noted an important caveat: people who use non-sugar sweeteners often differ from non-users in ways that independently affect health. They may already have higher body weight, diabetes, or other risk factors that led them to choose sweeteners in the first place. That makes it difficult to separate the sweetener’s effect from the person’s underlying health profile. The WHO classified its recommendation as conditional for this reason.
How to Reduce Your Risk
If you use stevia and are concerned about cardiovascular risk, the most practical step is reading labels carefully. Products that list erythritol as the first or second ingredient are primarily erythritol, not stevia. Pure stevia extract or liquid stevia drops typically contain steviol glycosides without bulking agents, making them a more straightforward option.
Some stevia products use other bulking agents like inulin (a plant fiber) or monk fruit extract instead of erythritol. These have not been linked to the same clotting concerns. If you prefer a granulated stevia product that measures like sugar, look for one that avoids erythritol specifically.
For people who already have cardiovascular risk factors like high blood pressure, diabetes, or a history of blood clots, the erythritol findings are worth paying attention to. The platelet reactivity data came from healthy volunteers, meaning the clotting effect isn’t limited to people who are already at risk. But those who are already prone to clotting events have less margin for anything that tips the balance further.