The Short Answer
For years, the only "danger" associated with sugar alcohols was severe gas and bloating. If you ate a sugar-free bar, you knew you might spend the afternoon running to the bathroom.
That changed in 2023 and 2024. Groundbreaking studies from the Cleveland Clinic discovered that erythritol and xylitol—the two "better" sugar alcohols—are linked to a significantly higher risk of blood clots, heart attack, and stroke.
While occasional consumption is likely fine for healthy adults, relying on these bars daily is no longer recommended, especially if you have heart health concerns.
Why This Matters
It’s not just a tummy ache anymore.
We used to tell people to switch from maltitol (the "fart sugar") to erythritol because it was easier on the gut. But emerging data suggests erythritol enters the bloodstream and makes your platelets "sticky," increasing the risk of forming dangerous clots.
The "Sugar-Free" lie.
Many bars claim to be "Keto" or "Low Sugar" by swapping 20g of sugar for 20g of sugar alcohol. Your body still has to process this load. In the case of maltitol, it even spikes your insulin almost as much as regular sugar, defeating the purpose entirely.
Bioaccumulation is real.
Erythritol is produced naturally in the body in tiny amounts. But a single protein bar can contain 1,000 times higher levels than your body ever sees naturally. The recent studies showed that these elevated levels linger in the blood for days after eating just one serving.
What's Actually In Your Bar?
Check the label for these "ol" ingredients. Here is the hierarchy of risk:
- Erythritol — The current industry darling for keto bars (like Is Quest Bar Clean|Quest). It doesn't cause gas, but it is now linked to cardiovascular risks. Related Slug
- Xylitol — Common in minty bars and gum. Toxic to dogs and now linked to increased clotting risk in humans.
- Maltitol — The "cheap" filler used in brands like ONE and Atkins. It causes severe bloating and has a high glycemic index. Avoid this strictly.
- Sorbitol — Often found in cheaper diet products. Known for its potent laxative effect even in small doses.
What to Look For
Green Flags:
- Sweetened with Fruit — Dates, bananas, or apples (e.g., Is Rxbar Actually Clean|RXBAR).
- Monk Fruit or Stevia — Natural, zero-calorie sweeteners with no known clotting risks.
- Allulose — A newer "rare sugar" that doesn't raise blood sugar or insulin, though long-term data is scarce.
Red Flags:
- "Sugar Alcohol" > 5g — Anything above this dose increases GI distress risk.
- Maltitol Syrup — Often the first or second ingredient in "low carb" candy bars.
- "Net Carbs" Marketing — Usually a trick to hide 20g of sugar alcohol.
The Best Options
If you want to avoid sugar alcohols entirely, look for bars sweetened with whole foods or monk fruit.
| Brand | Product | Verdict | Why |
|---|---|---|---|
| RXBAR | Protein Bar | ✅ | Sweetened with dates. Zero fake stuff. |
| Aloha | Plant-Based Bar | ✅ | Uses monk fruit and sugar. No alcohols. |
| Truvani | Only Bar | ✅ | 6 ingredients. Sweetened with dates/monk fruit. |
| Quest | Hero Bar | ⚠️ | Uses Allulose (better) but still processed. |
| ONE | Protein Bar | 🚫 | High Maltitol content. Guaranteed bloating. |
The Bottom Line
1. Ditch Maltitol immediately. It spikes blood sugar and wrecks digestion. There is no reason to eat it in 2026.
2. Treat Erythritol with caution. New heart health data is concerning. Don't make it a daily staple, especially if you have cardiovascular risks.
3. Real food is safer. A bar with 10g of sugar from dates is metabolically safer for most people than a bar with 20g of synthetic sugar alcohol.
FAQ
Does erythritol cause heart attacks?
Recent major studies have found an association between high erythritol levels and heart events. It appears to make blood platelets more likely to clot, which can trigger heart attacks or strokes.
Which sugar alcohol causes the most gas?
Maltitol and Sorbitol are the worst offenders. They ferment in the large intestine, pulling in water and creating gas. Erythritol is usually digested before it reaches the colon, so it rarely causes gas.
Is Stevia a sugar alcohol?
No. Stevia is a leaf extract, not a sugar alcohol. It does not carry the same clotting risks or digestive issues, though some people dislike the bitter aftertaste.