What is new?

The low-calorie sweetener xylitol is facing scrutiny. Analyzing the recent research reveals striking similarities to the public health conversations surrounding cigarettes in the 1960s.

Why it matters

Each generation encounters significant medical misunderstandings, from smoking to trans fats. The tobacco and food industries misled many for years, and we must remain vigilant to avoid repeating history.

What this article will add

This piece delves into the study's findings, highlighting key factors to consider moving forward.

Past and present

Do you recall when cigarettes were touted by health professionals as beneficial, even for children?

If you remember those advertisements, you might be celebrating milestone birthdays by now. Those ads span the 1930s to the 1950s.

In the 1980s, stick margarine was declared a "blessing for Americans’ arteries," according to The Fast-Food Guide.

It's one thing to chuckle at past health blunders; it's another to consider which of today's trends will become tomorrow's jokes. A leading contender could be xylitol, especially if you believe reports like this one from CNN:

“Common low-calorie sweetener linked to heart attack and stroke, study finds.”

If you've read my previous articles, you might anticipate a critical analysis of such headlines. Surprisingly, that claim might signify a pivotal moment in our relationship with synthetic sweeteners like xylitol. Just a year ago, I would have hesitated to take a firm stance due to insufficient evidence. However, the referenced study significantly expands our understanding; it is both methodologically sound and revealing in its outcomes.

Allow me to guide you through the findings of this research paper so you can draw your own conclusions.

What is Xylitol?

Xylitol is classified as a sugar alcohol, though it does not induce intoxication. It contains a hydroxyl (OH) group attached to each of its five carbon atoms, qualifying it as an alcohol in chemical terms. It resembles and tastes like sugar while offering several advantages:

• Contains 40% fewer calories (2.4 kcal/g compared to glucose's 4 kcal/g)
• Can be substituted for sugar in a 1:1 ratio during cooking
• Helps prevent blood sugar spikes

Additionally, xylitol imparts a refreshing sensation, which can mask unpleasant flavors in various medications, mouthwashes, and toothpastes.

While it's termed a synthetic sweetener, this designation stems from its production process, which involves byproducts from wood, corn, and rice. However, xylitol naturally occurs in fruits and plants, albeit in such low concentrations that extraction is not economically viable.

Our bodies produce xylitol as well, but in minimal amounts. Consuming xylitol-sweetened foods can elevate blood levels to 1000 times the natural concentration, in contrast to glucose, which raises blood sugar by only 10-30%.

This suggests we should scrutinize xylitol more closely. As the food industry incorporates it into low-calorie products at sugar-equivalent levels, it could lead to unprecedented xylitol exposure for consumers, a phenomenon that began in the 1960s.

The study results

The researchers conducted three separate clinical trials.

In the first study, they assessed the blood xylitol levels of 1157 individuals (ages 56–72) undergoing routine cardiac evaluations. They tracked these participants for three years to observe major adverse cardiac events (MACE). Those with the highest blood xylitol concentrations faced significantly greater risks than those in the lowest concentration group.

In the second study, the researchers sought to validate the xylitol-MACE relationship with a group of 2149 similarly aged individuals. Again, they found a strong correlation between higher xylitol levels and increased MACE incidents.

However, correlation does not imply causation.

Xylitol could be an incidental factor, influenced by an unrecognized third variable affecting both xylitol levels and MACE events. This potential confounding variable is something the researchers accounted for in their analysis, but unknown factors remain.

To further investigate xylitol's role, the third study aimed to identify a biological mechanism linking xylitol to these adverse cardiovascular events.

Xylitol: a prime suspect

Most MACEs stem from blood clot formation, or thrombosis. When a thrombus blocks blood flow to heart or brain tissue, the affected cells can suffer from oxygen deprivation, leading to heart attacks or strokes.

Thrombi consist of platelets, which act as the body's first response to blood vessel injuries. When activated, platelets adhere to each other and the damaged vessel wall, creating a plug to stop bleeding. However, if platelets activate without a genuine injury, problems can arise, especially in arteries already compromised by plaque.

To determine if xylitol causes platelet activation, the researchers conducted the third experiment.

They recruited ten healthy participants aged 26-40 who consumed 30 grams of xylitol dissolved in water after fasting overnight. This amount is comparable to what one might find in a pint of xylitol-sweetened ice cream or several pieces of xylitol candy.

The researchers monitored both the blood xylitol levels and the platelet aggregation response in blood samples.

The results showed a rapid rise in xylitol levels—within 30 minutes, reaching 1000 times higher than baseline, and returning to baseline levels within six hours.

Through testing the aggregation response of platelets to varying xylitol levels, they found that even at 30 micromoles, a level achieved shortly after ingestion, the clotting response increased significantly compared to 0 micromoles. At 300 micromoles, the response more than doubled from baseline.

These findings were corroborated through in vitro experiments with mice.

What does all that mean for you and me?

According to the researchers, their findings indicate…

“a direct effect of the low-calorie sweetener xylitol on platelet function and thrombosis potential in vivo.”

They caution that…

“xylitol may increase thrombosis risk in the very populations it is marketed to protect (e.g., individuals with diabetes, obesity, and cardiovascular disease).”

Health organizations need to reassess their stance on xylitol. The European Commission classifies xylitol as an approved food additive (E 967) with a "quantum satis" designation, implying no restrictions on consumption. The WHO shares this belief.

It’s not surprising that the food industry aims to develop cost-effective extraction methods to increase xylitol's prevalence in our diets. Currently, one in four children and nearly half of adults regularly consume xylitol, with women consuming it more than men. Xylitol consumption also correlates with body weight—heavier individuals tend to consume more.

This statistic contradicts xylitol's reputation as a weight-control aid, and it parallels the rising trends of obesity and diabetes.

The WHO appears to have recognized the ineffectiveness of artificial sweeteners for weight management and now advises against their use.

Reflecting on my comparison of xylitol to smoking, perhaps I exaggerate its dangers, but perhaps I don't.

Differentiating its effects from those of obesity, diabetes, and sedentary lifestyles is challenging—not due to a lack of analytical methods, but because xylitol is so prevalent in processed foods that accurately measuring consumption is nearly impossible. Even those who believe they avoid it may unknowingly ingest it, as many products not explicitly labeled "sugar-free" contain artificial sweeteners.

Additionally, xylitol is commonly used in toothpaste, gums, and medicines to mask unpleasant tastes.

Historically, isolating the health impacts of smoking was similarly difficult, as even non-smokers were often exposed to secondhand smoke.

Then there's the overlap in marketing tactics:

• backed by healthcare professionals
• promoted as a weight management solution
• viewed as child-friendly

We know how those narratives unfolded for cigarettes.

One argument against the notion of xylitol's potential harm is that not every blood clot results in a heart attack or stroke. Blood clots occur naturally, often going unnoticed, because our bodies have mechanisms like fibrinolysis that dissolve them. The processes of clot formation and dissolution depend on a complex interplay of factors that fluctuate throughout the day. Thankfully, the likelihood of these factors aligning to create a catastrophic event remains low.

But why would we want to increase that risk by unnecessarily activating platelets with xylitol?

My personal strategy

I avoid all artificial sweeteners. I remain skeptical of the health and weight management claims associated with substances foreign to our biology. The allure of maintaining weight without limiting sweets is enticing but seems too good to be true.

The recent revelations about xylitol's potential to elevate cardiovascular risk signal a warning, reminiscent of the shift in perspective regarding cigarettes in the mid-20th century. Today's fixation on artificial sweeteners may become tomorrow's punchline, just as smoking has for previous generations.

As I navigate my own health choices, I aim to adhere to practices that enhance my longevity. Steering clear of the misleading promises of sweeteners is one of those strategies.

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