Understanding WHO's Perspective on Non-Sugar Sweeteners: Key Insights
Written on
The WHO's Recent Statement on Non-Sugar Sweeteners
Recently, the World Health Organization (WHO) released a statement advising against the use of non-sugar sweeteners (NSS) for weight loss or preventing diseases often linked to high sugar intake, such as type 2 diabetes and heart disease.
According to their findings, "the use of NSS does not provide any long-term advantages for reducing body fat in both adults and children." They also noted potential negative effects from long-term NSS consumption, which may include an increased risk of type 2 diabetes, heart diseases, and even mortality among adults.
This guidance has sparked significant backlash. The International Sweeteners Association (ISA), based in Belgium, criticized the WHO's position, labeling it "a disservice to public health" for overlooking the beneficial role of NSS in lowering sugar and calorie consumption to manage weight. Similarly, the Calorie Control Council, a London-based food industry group, voiced strong objections, pointing out that the recommendation is categorized as "conditional," implying that the supporting evidence is not robust.
Allison Sylvetsky, an associate professor at the Milken Institute School of Public Health, remarked that "the recommendation could have been more nuanced in recognizing the potential benefits of non-sugar sweeteners for short-term weight loss when used wisely."
This raises the question: if NSS can be beneficial as some experts claim, under what conditions do they provide these advantages? Furthermore, what rationale led the WHO to recommend avoiding NSS?
To explore these questions, I examined the systematic review upon which the WHO's recommendation was founded. In this article, I will outline the findings of that review and the reasoning behind the WHO's stance.
Important Note: The recommendations and evidence discussed herein are meant for the general healthy population and do not extend to individuals with pre-existing diabetes.
A Brief Overview of Non-Sugar Sweeteners
Non-sugar sweeteners (NSS) provide a sweet flavor to foods and beverages without the calories associated with sugar. They are much sweeter than table sugar—ranging from 200 to 20,000 times sweeter—while containing negligible or zero calories. NSS encompass various artificial sweeteners such as saccharin, aspartame, cyclamate, acesulfame K (Ace-K), sucralose, neotame, and advantame, as well as natural sweeteners derived from plants like stevia.
These sweeteners are frequently referred to by various terms, including non-nutritive sweeteners (NNS), low-/no-calorie sweeteners, and high-intensity sweeteners.
WHO's Systematic Review
The systematic review entitled "Health Effects of Non-Sugar Sweeteners," published in 2022, serves as an update to the initial WHO-commissioned review from 2019.
In systematic reviews, at least two researchers evaluate the literature to identify pertinent studies on a specific topic. If discrepancies occur in study selection, they may engage in discussion to reach a resolution, or a third researcher may make the final call. All relevant studies—regardless of their findings—are analyzed to produce a comprehensive and unbiased summary.
If a minimum of two distinct studies from the systematic review present sufficient data, their information can be pooled for a meta-analysis; otherwise, the review concludes without moving to this stage.
The aim of this review is to investigate the potential health advantages and risks associated with NSS consumption, both in comparison to sugars and when consumed independently, within acceptable daily intake levels.
After reviewing 8,000 papers, the researchers narrowed down their focus to 283 studies that examined the effects of NSS on various factors, including:
- Body fatness (adiposity)
- Type 2 diabetes
- Cardiovascular diseases
- Cancer
- Dental health
- Chronic kidney disease
- Eating behaviors
- Sweet preferences
- Neurocognition
- Mood and behavior
- Asthma and allergies in children
The review also considered the impacts of NSS intake on overall mortality rates, as well as pregnancy and birth outcomes.
The researchers employed the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) methodology to assess the quality of each study included in the meta-analyses.
Next, let's delve into the findings of the review.
Outcomes from the Systematic Review and Meta-Analyses
- Body Fatness (Adiposity)
Out of the 283 studies, data from 32 Randomized Control Trials (RCTs) and 13 observational studies focused on body fatness were meta-analyzed. The results presented conflicting outcomes: while RCTs suggested that increased NSS consumption might lower body weight, observational studies indicated a rise in BMI and obesity risk.
For example, findings from 29 RCTs showed that higher NSS intake could result in a weight reduction between 0.28 kg to 1.13 kg in 95% of cases. Conversely, a meta-analysis of 23 observational studies revealed a mean increase of 0.14 kg/m² in BMI with higher NSS consumption.
- Type 2 Diabetes
Data from 12 observational studies on the risk of developing type 2 diabetes, alongside 21 RCTs and 3 observational studies on intermediate markers, were meta-analyzed. The findings suggested that higher NSS intake was linked to an increased risk of type 2 diabetes, although RCTs showed no effect on most diabetes markers.
- Cancer
Meta-analyses included data from 3 cohort studies on cancer mortality risk and 39 case-control studies on various cancer risks. Results indicated that higher NSS consumption had no effect on cancer mortality risk but was associated with a 31% increased risk of bladder cancer incidence.
- Cardiovascular Diseases
Findings from 19 RCTs on cardiovascular disease markers and 24 prospective cohort studies showed that higher NSS intake correlated with a 19% increased risk of cardiovascular disease mortality and a 32% higher risk of cardiovascular events.
- Chronic Kidney Diseases
Analysis of 2 RCTs and 2 observational studies showed that higher NSS intake was associated with a 64% increased risk of end-stage renal disease incidence.
- Pregnancy
Results from 3 observational studies indicated that higher NSS intake raises the risk of preterm birth by 25%, primarily during late preterm delivery.
- Neurocognition
Due to limited available studies, no meta-analyses were conducted for neurocognitive effects. However, findings from various studies suggested a potential link between NSS consumption and cognitive decline.
- Other Outcomes
A meta-analysis indicated a 12% increased risk of all-cause mortality with higher NSS intake. No significant relationships were found between NSS consumption and other outcomes such as mood, asthma, or allergies in children.
Understanding the Contradictions
The discrepancies between findings from RCTs and observational studies have led to questions about the nature of NSS consumption. The authors of the review speculated that reverse causation and varied NSS use patterns in observational studies might contribute to these inconsistencies.
Conclusion of the Systematic Review
After reviewing the evidence, the authors concluded that replacing sugars with NSS might result in short-term weight loss but is associated with long-term risks, including type 2 diabetes and cardiovascular diseases.
From Evidence to WHO's Recommendations
The NUGAG Subgroup on Diet and Health, responsible for formulating the WHO guidelines, took several factors into account, such as the balance of benefits and risks associated with NSS intake. Ultimately, they determined that the potential negative effects overshadow the benefits of NSS for most individuals.
Final Thoughts
So, should you consider NSS? If you are someone who consumes high amounts of sugar and wishes to reduce that intake, NSS may be beneficial. However, for the general population, their benefits are limited, and WHO's recommendation to avoid them is aimed at supporting long-term health and dietary goals.
In conclusion, while NSS can serve as a transitional tool for reducing sugar intake, relying on them long-term may not be advisable. A focus on balanced nutrition and a healthy lifestyle remains paramount.
Thank you for reading! If you found this analysis insightful, consider subscribing to my Medium email list or becoming a member for unlimited access. Your support is greatly appreciated!