Umbrella review assesses the association between artificially sweetened beverages and health outcomes

The food and beverage industry considers artificially sweetened beverages (ASBs) a healthier replacement for sugar-sweetened beverages (SSBs). This is because ASBs are sugar-free and have low or no calories.

A recent umbrella review evaluated the associations between ASBs and health outcomes. This review is available in Advances in Nutrition, which has also identified the biases and inconsistencies in previous meta-analyses and systematic reviews on this topic.

Background

In the United States, a significant reduction in regular soda sales was observed between 2006 and 2015. Instead, a spike in the sales of bottled water occurred. There is a high possibility that sales of sugary beverages will be affected by the availability of healthier choices. 

Even though manufacturing companies claim artificially sweetened products are safe for consumption, a large amount of evidence has been documented that disagrees with this claim. These studies have shown that ASBs rapidly modify the gut microbial population in mice and humans. This alteration can significantly affect the metabolism, fat storage, and appetite of an individual. 

Several meta-analyses and systematic reviews have correlated high ASB consumption with a higher risk of all-cause mortality and CVD mortality. In addition, this group of individuals is at an elevated risk of cancer incidence.

Methodology

To examine the link between ASB and health outcomes, this study obtained relevant systematic reviews from Embase, Web of Science, and PubMed, published up to 25 May 2022. The PRISMA 2020 guidelines were followed in all studies. The current umbrella review considered cohort-based studies that used a healthy population at baseline, case-control studies, and randomized controlled trials.

Some meta-analyses that provided weak evidence due to their study design were excluded. If a meta-analysis considered a mixture of studies, such as cohort, cross-sectional, and case-control evidence, the cross-sectional aspect was excluded, and the meta-analysis was reanalyzed. In addition, systemic reviews that pooled data associated with energy drinks, SSBs, or juices, were excluded. This study did not include any narrative reviews and systematic reviews published as conference abstracts.

The methodological quality of systematic reviews was assessed using the tool AMSTAR-2. This tool enabled the detection of high-quality systemic reviews based on multiple factors, including adherence to study protocol, justification of the selected study design, comprehensive search strategy, data extraction and study selection in duplicate, and identification of biased data. In addition, funding agencies and sources of statistical heterogeneity were considered. 

The impacts of ASBs were assessed based on cardiovascular mortality, chronic kidney disease, gastrointestinal cancer, all-cause mortality, colorectal cancer, type 2 diabetes, obesity, CVD incidence, pancreatic cancer, and hypertension.

Study findings

A total of eleven studies satisfied all the required criteria. The selected reports comprised fifty-one cohort studies and four case-control studies. Most of these studies indicated that ASBs are associated with a higher risk of cardiovascular mortality, hypertension, all-cause mortality, type 2 diabetes, obesity, and CVD incidence. This review added two additional health outcomes, i.e., stroke and coronary artery disease (CAD), liked to ASBs consumption.

In certain meta-analyses of ASBs, original data of only SSBs were pooled. However, in other cases, the authors pooled SSBs and ASBs data, or SSBs, ASBs and juices data. Exposure variables, such as artificial sweeteners, have been poorly described in most studies.

All meta-analyses exhibited small study effects bias. However, regarding the certainty of the evidence, none of the associations investigated in this study were validated with strong supporting evidence. For instance, the link between ASBs and type 2 diabetes, obesity, hypertension, CVD incidence, and all-cause mortality was backed up by highly suggestive evidence. Weak evidence was found for pancreatic cancer, cardiovascular mortality, gastrointestinal cancer, CAD, and stroke.

While assessing the methodological quality of the selected studies, most studies were found to follow Population, Exposure, Comparison, and Outcome (PECO) elements to describe the aims and method of the systematic review. Out of eleven reports, three had a well-developed study protocol. It was noted that all systematic reviews only partially described the used search strategy. Furthermore, none of the reports provided details about the study funding of each original study selected in different reviews. Some of the studies utilized suitable statistical tools for data analysis.

Many animal studies revealed that some artificial sweeteners may induce gut wall immune reactivity. Artificial sweeteners, such as stevia, saccharin, sucralose, and acesulfame potassium, indirectly disrupt immunological response. Strong clinical evidence has been found that ASBs consumption influences sweet taste receptors and brain communications.

Conclusion

High ASBs consumption exhibited a statistically significant association with type 2 diabetes, cardiovascular mortality, all-cause mortality, chronic kidney disease, obesity, hypertension, CVD incidence (CAD and stroke), and pancreatic cancer. However, weak evidence and statistical significance have supported several of these outcomes. Gut microbial dysbiosis or increased production of inflammatory markers could be the possible mechanisms that correlate ASBs and health outcomes. In the future, more research is required to validate the chronic effects of ASBs.

Written by

Dr. Priyom Bose

Priyom holds a Ph.D. in Plant Biology and Biotechnology from the University of Madras, India. She is an active researcher and an experienced science writer. Priyom has also co-authored several original research articles that have been published in reputed peer-reviewed journals. She is also an avid reader and an amateur photographer.