Does Xylitol Cause Cardiovascular Disease?
Recently, Witkowski et al. published a study in the European Heart Journal titled “Xylitol is prothrombotic and associated with cardiovascular risk”. The authors concluded that xylitol increases the risk of blood clots and is associated with elevated risk of Major Adverse Cardiovascular Events (MACE), including heart attacks, strokes, and death. The findings were quickly headlined by mainstream media such as The Washington Post and CNN and caused widespread alarm.
What is Xylitol?
Before we start, let’s introduce two key scientific terms: endogenous & exogenous. Substances that are produced inside of our bodies are referred to as endogenous substances. Examples of such are amino acids, hormones, and antibodies. Substances produced outside of our bodies which then enter our body through various pathways (ingestion, inhalation, absorption, etc.) are referred to as exogenous substances. Our body produces xylitol as a metabolite (i.e. “product”) during glucose metabolism. Xylitol can also be found in small quantities in fruits and vegetables. Finally, xylitol can be manufactured and used as a sugar substitute in artificially sweetened foods and beverages. Therefore, the xylitol molecules detected in our plasma can come from both endogenous and exogenous sources.
Why is xylitol good for our teeth?
Studies have shown that xylitol can disrupt the energy production process of cariogenic (cavity causing) microorganisms, decreases acid production from bacteria fermentation and reduces the ability of cariogenic bacteria to adhere to the teeth surfaces. Additionally, xylitol gum can stimulate saliva flow, increase oral pH levels, and eliminate food debris. Clinical findings indicated that chewing xylitol containing gum 5-6g/day for at least 5 minutes can significantly decrease the risk of caries. Due to its unique anti-cariogenic (cavity-fighting) properties, xylitol is a common ingredient in sugar-free candy, gum and oral care products.
Limitations of Witkowski et al.’s Xylitol Study
The recent study published by Witkowski et al. has several limitations:
- The xylitol as well as plasma platelet concentrations used in the study are near or above the upper limits of physiological concentrations observed in human subjects.
- There was no evidence that the human subjects in the study regularly consumed large quantities of xylitol. Therefore, the association between xylitol and increased cardiovascular event risk is due to endogenous xylitol.
- People with diabetes and other metabolic diseases are found to have elevated xylitol along with other inflammatory molecules that are associated with cardiovascular risks. Hence, it is unclear whether the increase in cardiovascular risks reported in the study was due to xylitol or other preexisting disease conditions.
- Besides the fact that mice have very poor absorption of dietary xylitol, they almost never develop coronary artery disease due to their lipid biology. Both factors make them very poor models for studying human cardiovascular risks.
Take Home message.
Based on the limitations discussed above, there is no reason to panic about xylitol:
- The study failed to establish that xylitol causes major cardiovascular events.
- The test subjects in the study ingested water sweetened with 30g of xylitol, while 10 pieces of xylitol gum only contains around 6.5 g of Xylitol.
- Considering its various benefits for oral health, there is no reason to refrain from chewing xylitol containing gum. Candies containing xylitol are also safe to consume to curb occasional sugar cravings. Frequent and regular consumption of large quantities of xylitol, or any sugar substitute for that matter, is a bad idea.