Are you trying to control your sugar intake but still have a sweet tooth? If so, the sugar-free cookies and snack cakes on the grocery store shelf may be tempting. Don't toss a box in your cart just yet, though. Recent research shows some of those no-sugar goodies may be too good to be true.
Lots of low-calorie, low-carbohydrate foods and drinks contain the sugar substitute xylitol. However, new evidence shows consuming high levels of xylitol can increase your risk for heart attack and stroke.
Thomas O'Brien, MD, a cardiologist and president of The Christ Hospital Heart & Vascular Institute, explains what xylitol is and what you should know about how it can impact your heart.
What is xylitol?
Xylitol is a sugar alcohol, a type of naturally occurring carbohydrate. It tastes like sugar, but it has 40% fewer calories. Sugar alcohols, like xylitol, mannitol, sorbitol or lactitol, are found in fruits and vegetables in small amounts.
As a low-calorie sugar substitute, xylitol is frequently used in many foods labeled “keto-friendly." These products are popular with people who are trying to lose weight, control their heart disease or manage their diabetes. Xylitol is also a common ingredient in sugar-free candy, gum, mints and some flavoring packets for water.
The risks of xylitol
Xylitol reduces your calorie intake and can keep your insulin levels from spiking — key benefits for people with diabetes. But recent findings also show it can cause the platelets in your blood to stick together, creating clots. And these clots significantly increase your risk of having a heart attack or stroke.
These findings come from a study published in the European Heart Journal. Researchers examined xylitol levels in about 3,000 participants and found that people with the highest levels of xylitol in their blood experienced more platelet clumping. As a result, those individuals had over a 50% increase in their risk of heart attack, stroke or death within three years. The same group of researchers discovered similar results with another sugar alcohol — erythritol — last year.
“The kicker is that the impact of xylitol, or any of these sugar alcohols, is related to the dose. The small amounts that we're exposed to in a natural diet wouldn't be expected to have negative consequences or impact our platelets," Dr. O'Brien says. “But the dose in these diet or low-carb keto foods literally contains 1,000 times the amount we're supposed to consume. You're getting way more xylitol than you need just by eating one keto cookie."
The study results showed that participants' xylitol levels did decline after six hours. But additional blood tests revealed that xylitol never completely disappeared from their bloodstream. That means if you frequently consume foods or drinks that contain xylitol, it could build up in your blood.
What the xylitol impact could mean for you
Although investigators need to do more research, Dr. O'Brien says it's clear that foods containing xylitol and other sugar alcohols can raise cardiovascular risks for everyone. However, they can be particularly dangerous for people who already have heart issues. That includes people who are overweight or obese or who have pre-diabetes or diabetes.
“We know some of the risks that come with obesity can include excess inflammation and insulin resistance. That inflammation may increase someone's risk for clotting," he says. “So, there may be a particular concern about exposing people who already face an increased clotting risk to the additional clotting risks posed by these sugar alcohols."
Dr. O'Brien cautions that blood-thinning medications may not reduce xylitol's risks. Not all blood thinners affect your platelets. And there's also no research to show that blood thinners that do impact your platelets would be able to prevent xylitol's platelet-clumping effect.
Reducing your risk from xylitol
Dr. O'Brien says eating fewer foods that contain xylitol is the best way to prevent the negative impact it can have on your heart and cardiovascular system.
“The biggest takeaway is that we need to go back to real, natural foods. It's human nature to want a quick fix. But we can't look for the easy way out or avoid the hard work if we want to lose weight or manage pre-diabetes or diabetes," he says. “It's normal to still want something sweet that may not have all the calories or the sugar. However, these sugar substitutes are just another potential problem. So, when you eat foods that contain them, you're simply trading one risk for another."
Instead, focus on eating naturally sweet foods, like fruits or honey, in moderation. To reduce your risk further, check nutrition labels for any sugar alcohols. Most end in “itol," and they are listed under carbohydrates. If they're included on the nutrition label, you can be certain the product contains an unhealthy level of sugar alcohol.
Ultimately, Dr. O'Brien says, avoiding xylitol and other sugar alcohols is a good way to limit any added cardiovascular risks.
“More and more, it looks like this bucket of fake sugars or fake sweeteners isn't the easy way out that everyone had hoped it would be," he says.