The Intake of Ultra-Processed Foods and Prevalence of Chronic Kidney Disease: The Health Examinees Study

Ultra-processed food consumption and the risk of incident chronic kidney disease: a systematic review and meta-analysis of cohort studies

BACKGROUND

Recent individual studies have indicated that ultra-processed food (UPF) consumption may be associated with the incidence of chronic kidney disease (CKD). We conducted a systematic review and meta-analysis based on those longitudinal studies evaluating the relationship between UPF consumption and the risk of incident CKD, and synthesizing the results.

METHOD

PubMed, Embase, The Cochrane Library, Web of Science, and Scopus were searched from inception through 22 March 2023. Any longitudinal studies evaluating the relationship between UPF consumption and the risk of incident CKD were included. Two researchers independently conducted the literature screening and data extraction. RR and its 95% CI were regarded as the effect size. The Newcastle-Ottawa Scale (NOS) was applied to assess the quality of the studies included, and the effect of UPF consumption on the risk of incident CKD was analyzed with STATA version 15.1. This study's protocol was registered in PROSPERO (CRD42023411951).

RESULTS

Four cohort studies with a total of 219,132 participants were included after screening. The results of the meta-analysis suggested that the highest UPF intake was associated with an increased risk of incident CKD (RR = 1.25; 95% CI: 1.18-1.33).

CONCLUSIONS

High-dose UPF intake was associated with an increased risk of incident CKD. However, the underlying mechanisms remain unknown. Thus, more standardized clinical studies and further exploration of the mechanisms are needed in the future.

The association between ultra-processed food and common pregnancy adverse outcomes: a dose-response systematic review and meta-analysis

OBJECTIVES

Given the increasing incidence of negative outcomes during pregnancy, our research team conducted a dose-response systematic review and meta-analysis to investigate the relationship between ultra-processed foods (UPFs) consumption and common adverse pregnancy outcomes including gestational diabetes mellitus (GDM), preeclampsia (PE), preterm birth (PTB), low birth weight (LBW), and small for gestational age (SGA) infants. UPFs are described as formulations of food substances often modified by chemical processes and then assembled into ready-to-consume hyper-palatable food and drink products using flavors, colors, emulsifiers, and other cosmetic additives. Examples include savory snacks, reconstituted meat products, frozen meals that have already been made, and soft drinks.

METHODS

A comprehensive search was performed using the Scopus, PubMed, and Web of Science databases up to December 2023. We pooled relative risk (RR) and 95% confidence intervals (CI) using a random-effects model.

RESULTS

Our analysis (encompassing 54 studies with 552,686 individuals) revealed a significant association between UPFs intake and increased risks of GDM (RR = 1.19; 95% CI: 1.10, 1.27; I2 = 77.5%; p < 0.001; studies = 44; number of participants = 180,824), PE (RR = 1.28; 95% CI: 1.03, 1.59; I2 = 80.0%; p = 0.025; studies = 12; number of participants = 54,955), while no significant relationships were found for PTB, LBW and SGA infants. Importantly, a 100 g increment in UPFs intake was related to a 27% increase in GDM risk (RR = 1.27; 95% CI: 1.07, 1.51; I2 = 81.0%; p = 0.007; studies = 9; number of participants = 39,812). The non-linear dose-response analysis further indicated a positive, non-linear relationship between UPFs intake and GDM risk Pnonlinearity = 0.034, Pdose-response = 0.034), although no such relationship was observed for PE (Pnonlinearity = 0.696, Pdose-response = 0.812).

CONCLUSION

In summary, both prior to and during pregnancy, chronic and excessive intake of UPFs is associated with an increased risk of GDM and PE. However, further observational studies, particularly among diverse ethnic groups with precise UPFs consumption measurement tools, are imperative for a more comprehensive understanding.

Ultra-processed food consumption and chronic kidney disease risk: a systematic review and dose-response meta-analysis

Background

High intake of ultra-processed food (UPF) has been associated with increased risk of chronic kidney disease(CKD), but the results remain inconsistent. We therefore performed this systematic review and dose–response meta-analysis of observational studies that shed light on the association between UPF consumption and the risk of CKD.

Methods

A systematic literature search of PubMed, Embase, Web of Science, Scopus and China National Knowledge Infrastructure (CNKI) databases was carried out to find the eligible articles published up to October 31, 2023. Random-effects or fixed-effects models were used to pool the relative risks(RRs) and their 95% confidence intervals (CIs).The potential sources of heterogeneity across studies were examined using the Cochran’s Q test and I-square(I2). Publication bias was examined using the visual inspection of asymmetry in funnel plots and quantified by Begg’s and Egger’s tests.

Results

Eight studies (six cohort and two cross-sectional studies) exploring the association between UPF consumption and risk of CKD, were included in the final analysis. The pooled analyses revealed that high consumption of UPF was associated with an increased risk of CKD (RR = 1.25; 95%CI: 1.09–1.42, p &lt; 0.0001). Moreover, a 10% increase of UPF consumption was associated with a 7% higher risk of CKD (RR = 1.07; 95%CI: 1.04–1.10, p &lt; 0.001). Dose–response analysis of all included studies showed a linear association between UPF consumption and the risk of CKD (RR = 1.02; 95%CI:0.99–1.05, Pdose–response = 0.178, Pnonlinearity = 0.843).

Conclusion

Our findings indicate that high consumption of UPF is significantly associated with an increased risk of CKD. Future research with prospective design is required to confirm this positive association.

Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023478483, PROSPERO identifier CRD42023478483.

From ultra-processed foods towards healthy eating for CKD patients: a proposal of educational infographics

Ultraprocessed food (UPF) is defined as industrialized, packaged and ready-to-eat food produced on a large scale, using sophisticated industrial machinery. Examples of UPFs include salty and sweet snacks, industrialized biscuits and packaged meals, processed meats and sugary drinks. Ultraprocessed food has a long-shelf life, is highly palatable, microbiologically safe, affordable and most of all, easy to consume. For these reasons, its consumption has been increasing worldwide, and is replacing healthy homemade meals. The main concern of this dietary shift is that UPFs come with the addition of salt, sugar, unhealthy fats, and several additives and taste enhancers that contain, among other substances, relevant quantities of potassium, phosphate and sodium. A large proportion of UPF in the diet may carry risks for patients with chronic kidney disease (CKD) since it can worsen blood pressure and glycemic control, and lead to constipation, hyperkalemia and hyperphosphatemia. Acknowledging the importance of UPF in kidney health implies integrating nutritional counseling with information on UPFs, and specific educational material can be helpful for patients, caregivers, and also for health care providers. We developed a set of 3 infographics dedicated to CKD patients, with information on how to identify UPFs, reasons for decreasing consumption, how to compose a healthy CKD plate and tips for reading food labels in supermarkets and grocery shops. We hope that this material can be useful in CKD outpatient clinics and dialysis centers as well as in general practitioners' offices, caring for early stage CKD.

Ultraprocessed food consumption, genetic predisposition, and the risk of gout: the UK Biobank study

OBJECTIVE

This study aimed to examine the interactions between ultraprocessed food (UPF) consumption and genetic predisposition with the risk of gout.

METHODS

This prospective cohort study analysed 181 559 individuals from the UK Biobank study who were free of gout at baseline. UPF was defined according to the NOVA classification. Assessment of genetic predisposition for gout was developed from a genetic risk score of 33 single nucleotide polymorphisms. Cox proportional hazards were used to estimate the associations between UPF consumption, genetic predisposition and the risk of gout.

RESULTS

Among the 181 559 individuals in the study, 1558 patients developed gout over 1 648 167 person-years of follow-up. In the multivariable adjustment model, compared with the lowest quartile of UPF consumption, the hazard ratio (HR) and 95% CI of the highest UPF consumption was 1.16 (1.01, 1.33) for gout risk, and there was a non-linear correlation between UPF consumption and the development of gout. In substitution analyses, replacing 20% of the weight of UPF in the daily intake with an equal amount of unprocessed or minimally processed food resulted in a 13% lower risk of gout (HR: 0.87; 95% CI: 0.79, 0.95). In the joint-effect analysis, the HR (95% CI) for gout was 1.90 (1.39, 2.60) in participants with high genetic predisposition and high UPF consumption, compared with those with low genetic predisposition and low UPF consumption.

CONCLUSION

In summary, UPF consumption was found to be associated with a higher risk of gout, particularly in those participants with genetic predisposition to gout. Our study indicated that reducing UPF consumption is crucial for gout prevention.

The role of ultra-processed food consumption in protein-energy wasting and sarcopenia development in patients with chronic kidney diseases

BACKGROUND

The effect of ultra-processed foods (UPFs) on chronic kidney disease (CKD) has been studied in some studies. The present study aimed to investigate the association between UPF consumption and the risk of protein-energy wasting (PEW) and sarcopenia in patients with CKD in the Iranian population.

METHODS

The current cross-sectional study included 110 patients with CKD referred to two clinics in Shiraz, Iran. The International Society of Renal Nutrition and Metabolism (ISRNM) criteria and the Asian Working Group for Sarcopenia (AWGS) guideline were considered for the diagnosis of PEW and sarcopenia, respectively. The valid semi-quantitative food frequency questionnaire was used to assess participants' dietary intake. The logistic regression was used to examine the association of UPFs with PEW and sarcopenia.

RESULTS

We observed no significant association between sarcopenia and PEW with UPFs in the crude model. After adjusting for confounders, we observed a significantly higher odds of sarcopenia in the upper versus lower median of UPF intake (odds ratio (OR) = 3.59, 95% confidence interval (CI): 1.02-12.62, P = 0.046).

CONCLUSIONS

Our findings suggest a positive relationship between UPF intake and sarcopenia among CKD patients. Therefore, reducing the intake of UPFs may decrease the odds of sarcopenia in patients suffering from CKD.

Associations between ultra-processed food consumption and kidney function in an older adult population with metabolic syndrome

BACKGROUND & AIMS

Ultra-processed food (UPF) consumption has increased dramatically over the last decades worldwide. Although it has been linked to some cardiometabolic comorbidities, there is limited evidence regarding kidney function. This study aimed to cross-sectionally and longitudinally assess the association between UPF consumption and estimated-glomerular filtration rate (eGFR) based on Cystatin C (CysC).

METHODS

Older adults (mean age 65 ± 5.0 years, 46% women) with overweight/obesity and metabolic syndrome (MetS) who had available data of CysC at baseline (n = 1909), at one-year and at 3-years of follow-up (n = 1700) were analyzed. Food consumption was assessed using a validated 143-item semi-quantitative food frequency questionnaire and UPF consumption (% of g/d) at baseline and changes after one-year of follow-up were estimated according to NOVA classification system. Multivariable-adjusted linear and logistic regression models were performed to evaluate the cross-sectional associations between UPF consumption with eGFR levels and decreased kidney function (eGFR <60 ml/min/1.73 m2) at baseline. Multivariable-adjusted mixed-effects linear regression models were fitted to investigate the associations between one-year changes in UPF and eGFR over 3-years of follow-up.

RESULTS

Individuals with the highest baseline UPF consumption showed lower eGFR (β: -3.39 ml/min/1.73 m2; 95% CI: -5.59 to -1.20) and higher odds of decreased kidney function (OR: 1.64; 95% CI: 1.21 to 2.22) at baseline, compared to individuals in the lowest tertile. Participants in the highest tertile of one-year changes in UPF consumption presented a significant decrease in eGFR after one-year of follow-up (β: -1.45 ml/min/1.73 m2; 95% CI: -2.90 to -0.01) as well as after 3-years of follow-up (β: -2.18 ml/min/1.73 m2; 95% CI: -3.71 to -0.65) compared to those in the reference category.

CONCLUSIONS

In a Mediterranean population of older adults with overweight/obesity and MetS, higher UPF consumption at baseline and one-year changes towards higher consumption of UPF were associated with worse kidney function at baseline and over 3-years of follow-up, respectively.

CLINICAL TRIAL REGISTRY NUMBER

ISRCTN89898870.

Ultraprocessed foods and chronic kidney disease-double trouble

High energy intake combined with low physical activity generates positive energy balance, which, when maintained, favours obesity, a highly prevalent morbidity linked to development of non-communicable chronic diseases, including chronic kidney disease (CKD). Among many factors contributing to disproportionately high energy intakes, and thereby to the obesity epidemic, the type and degree of food processing play an important role. Ultraprocessed foods (UPFs) are industrialized and quite often high-energy-dense products with added sugar, salt, unhealthy fats and food additives formulated to be palatable or hyperpalatable. UPFs can trigger an addictive eating behaviour and is typically characterized by an increase in energy intake. Furthermore, high consumption of UPFs, a hallmark of a Western diet, results in diets with poor quality. A high UPF intake is associated with higher risk for CKD. In addition, UPF consumption by patients with CKD is likely to predispose and/or to exacerbate uraemic metabolic derangements, such as insulin resistance, metabolic acidosis, hypertension, dysbiosis, hyperkalaemia and hyperphosphatemia. Global sales of UPFs per capita increased in all continents in recent decades. This is an important factor responsible for the nutrition transition, with home-made meals being replaced by ready-to-eat products. In this review we discuss the potential risk of UPFs in activating hedonic eating and their main implications for health, especially for kidney health and metabolic complications of CKD. We also present various aspects of consequences of UPFs on planetary health and discuss future directions for research to bring awareness of the harms of UPFs within the CKD scenario.

Relationship of ultra-processed food consumption and new-onset chronic kidney diseases among participants with or without diabetes

BACKGROUND

Whether diabetes and genetic susceptibility of kidney diseases modifies the relationship between ultra-processed foods (UPF) consumption and incident chronic kidney disease (CKD) remains uncertain. We aimed to investigate the association between UPF consumption and new-onset CKD in participants with and without diabetes, and explore whether genetic risks of kidney diseases may modify the association.

METHODS

153,985 participants who were free of CKD at baseline and provided 24-h dietary recalls in the UK Biobank were included. UPF was defined according to the NOVA classification. The energy contribution of UPF was calculated by dividing the energy intake of UPF by the total energy intake. The study outcome was new-onset CKD, ascertained by self-report data and data linkage with primary care, hospital admissions, and death registry records.

RESULTS

During a median follow-up of 12.1 years, 4,058 participants developed new-onset CKD. There was a significant positive association between UPF consumption and new-onset CKD in total participants (per 10% increment, adjusted hazard ratio (HR) 1.04; 95% confidence interval (CI) [1.01;1.06]. The positive association between UPF consumption and risk of new-onset CKD was significantly stronger in participants with diabetes (per 10% increment, adjusted HR 1.11 [1.05;1.17]) than in those without diabetes (per 10% increment, adjusted HR 1.03 [1.00;1.05]; P-interaction = 0.005). Genetic risks of kidney diseases did not significantly modify the positive association in those with or without diabetes (all P-interactions > 0.05).

CONCLUSION

There was a significantly stronger positive association between UPF consumption and new-onset CKD in participants with diabetes compared with those without diabetes.