Comprehensive analysis shows ultra-processed foods elevate metabolic disease risks

A pivotal study published in Frontiers in Nutrition meticulously explores the connection between the intake of ultra-processed foods (UPFs) and the heightened risk of metabolic disorders.

The consumption of UPFs is often discouraged due to its potential role in fostering metabolic conditions such as type 2 diabetes mellitus (T2DM) and obesity. These conditions detrimentally impact various bodily systems by disrupting the normal breakdown and synthesis of substances during metabolism.

Although the root causes of metabolic disorders are complex and multifaceted, encompassing both genetic and environmental factors, diet emerges as a significant, modifiable environmental aspect.

Employing the NOVA food classification system, UPFs are identified as products of industrial processing, comprising extracted ingredients, additives, and minimal whole foods. Common examples include baked goods, processed snacks, sausages, and sugar-laden drinks.

Despite the established linkage between UPF consumption and metabolic diseases, critiques exist regarding the potential bias within the research findings.

This investigation conducted an umbrella review (UR), meticulously examining published systematic reviews coupled with meta-analyses to affirm the strength and validity of the association between UPF intake and the risk of metabolic diseases.

Databases such as Web of Science, PubMed, Embase, and the Cochrane Library were exhaustively searched up to July 15, 2023, without language limitations. The search also included citation tracking to identify additional relevant studies.

Exclusion criteria targeted studies focusing on laboratory and animal research, genetic polymorphisms, and those lacking specific data or quantitative analysis. Studies incorporating fewer than three original research articles were also omitted from the meta-analysis.

A thorough analysis of 13 meta-analyses was conducted, revealing a consistent association between UPF consumption and the onset of obesity and T2DM.

Notably, seven cross-sectional and numerous prospective cohort studies identified a 1.55 times increased risk of obesity with high UPF consumption, underscoring UPFs as a significant obesity risk factor. These results advocate for a reduction in UPF intake, highlighting a potential health benefit that healthcare professionals and policy makers should consider when developing dietary recommendations.

Furthermore, two meta-analyses indicated a significant link between UPF consumption and T2DM, with processed meats and sugar-sweetened beverages being particularly implicated. The consumption levels of these UPFs were closely tied to T2DM risk.

However, evidence supporting the connection between T2DM and UPF intake was weaker in some analyses and deemed insignificant among Asian populations.

Risks for non-alcoholic fatty liver disease (NAFLD), hypertension, and metabolic syndrome (MetS) were also associated with UPF consumption, though these findings were less consistent across different groups, indicating a need for further research.

This study underscores the association between UPF intake and an increased risk of metabolic diseases, especially obesity and T2DM, while suggesting the necessity for additional research on other metabolic conditions.

A key strength of this research lies in its thorough evaluation of the quality and credibility of each meta-analysis, marking it as the first UR to provide a comprehensive summary of the link between UPFs and metabolic diseases.

Limitations include the potential absence of specific data in underlying studies and the exclusion of certain studies in previous meta-analyses. Future research should expand to include other outcomes such as hyperuricemia and dyslipidemia. The study also did not account for residual confounding and measurement errors due to the absence of randomised controlled trials.

The consistency in defining UPFs was challenging, as few studies applied the NOVA classification system, and some meta-analyses included a mix of studies with and without this system, possibly leading to misclassification.

Moreover, the generalisability of these findings may be questioned, as the majority of the research was conducted in the United States, several European countries, and Brazil, suggesting a potential geographical bias in the results.