Ultra-Processed Food Intake and Risk of Colorectal Cancer: A Matched Case-Control Study

Ultra-Processed Food Consumption and Gastrointestinal Cancer Risk: A Systematic Review and Meta-Analysis

INTRODUCTION

Ultra-processed food (UPF) intake has been associated with a higher risk of obesity, hypertension, type 2 diabetes, and cardiovascular diseases. The initial data on the relationship between UPF consumption and cancer risk were derived from retrospective observational studies with conflicting results. This systematic review and meta-analysis of prospective cohort studies aimed to investigate the association between UPF consumption and gastrointestinal cancer risk.

METHODS

PubMed, Embase, and Cochrane databases were searched for prospective cohort studies that compared the highest vs the lowest level of UPF consumption according to NOVA food classification and reported the risk of gastrointestinal cancers by subsite. The association with cancer was quantified as hazard ratios (HR) using a random-effects model.

RESULTS

Five prospective cohort studies were included in this review comprising 1,128,243 participants (241,201 participants in the highest and 223,366 in the lowest levels of UPF consumption). The mean follow-up ranged from 5.4 to 28 years. The highest UPF consumption was significantly associated with an increased risk of colorectal cancer (HR 1.11; 95% confidence interval [CI] 1.03-1.21; P = 0.01; I2 = 31%), colon cancer (HR 1.12; 95% CI 1.02-1.23; P = 0.02; I2 = 0%), and non-cardia gastric cancer (HR 1.43; 95% CI 1.02-2.00; P = 0.04; I2 = 0%) compared with the lowest UPF intake. However, no association was found between high UPF consumption and hepatocellular, esophageal, pancreatic, gastric cardia, and rectal cancer.

DISCUSSION

The highest level of UPF consumption was significantly associated with colorectal and non-cardia gastric cancer.

Ultraprocessed foods and cancer risk: the importance of distinguishing ultraprocessed food groups

Several case-control, cohort studies, and meta-analyses found a moderate association between ultraprocessed food consumption and the risk of colorectal and a few other cancers. The evidence is, however, not consistent. A reason for such inconsistence is that the NOVA classification of ultraprocessed foods may include unfavorable but also favorable dietary components, and it may vary across different populations.

Ultraprocessed Foods and Cancer in Low-Middle-Income Countries

Low middle income countries (LMICs) are the predominant contributors to global cancer-related mortality and are projected to bear the greater share of the global cancer burden in the next few decades. Among other factors, lifestyle changes have been linked to the rising incidence of cancer in these countries. As one of the keys to a healthy lifestyle, a balanced diet plays a major role in the preservation of health. Globalization and rapid urbanization have prompted a paradigm shift in various aspects of daily life in LMICs; the influence on dietary choices has been particularly noticeable. Studies show a concerning rise in the sale and consumption of ultraprocessed foods in these countries. In addition to hyperpalatability, this trend has been attributed to various other factors including convenience, availability, economic considerations, and marketing strategies. Although several studies from LMICs recognize and recommend the need for effective public health measures to reduce the consumption of these foods, findings from certain studies suggest that established public health strategies occasionally fail in the real-world scenario. Barriers to effective policymaking also contribute to the prevailing dietary trends. This review of studies from the LMIC setting demonstrates the current problem, limitations of established public health measures, and the complexities associated with effective policymaking. In view of the threat posed to cancer risk, there is an urgent need to curb the consumption of ultraprocessed foods in LMICs. National policymakers therefore need to circumnavigate the challenges effectively to ensure timely achievement of the United Nations sustainable development goals.

The association between ultra-processed foods and conventional markers of cardiovascular risk in an adult Iranian population

BACKGROUND AND AIMS

According to the NOVA classification system, ultra-processed foods result from extensive industrial processing and use ingredients derived from food and non-food products, which can negatively impact on cardiovascular disease risk factors. Despite this, few studies have investigated UPFs in Middle Eastern populations regardless of high consumption in this region.

METHODS AND RESULTS

This cross-sectional study was conducted on data from the Prospective Epidemiological Research Studies in Iran Kharemeh cohort (n = 6611). Food frequency questionnaires were assessed and the ratio of total UPFs energy/total energy intake was calculated. Data was categorized into tertiles of UPF consumption using the NOVA classification system. Kruskal-Wallis tests were used to assess differences in nutrient and food intakes between tertiles and logistic regression analysis was applied to assess the associations between UPFs and CVD risk factors. After adjustment for potential confounders the logistic regression analysis revealed significant positive relationships between intakes of UPFs and waist circumference (WC) (T2: OR; 1.34, 95% CI; 1.13-1.60 - T3: OR; 1.41, 95% CI; 1.18-1.69, P ˂0.001), low-density lipoprotein cholesterol (LDL-C) (T2: OR; 1.20, 95% CI; 1.05-1.37 - T3: OR; 1.27, 95% CI; 1.11-1.45, P ˂0.001), non-high-density lipoprotein cholesterol (non-HDL) (T2: OR; 1.21, 95% CI; 1.07-1.37 - T3: OR; 1.24, 95% CI; 1.10-1.41, P ˂0.001) and LDL-C to HDL-C ratio (T2: OR; 1.15, 95% CI; 1.02-1.31 - T3: OR; 1.21, 95% CI; 1.07-1.38, P = 0.002).

CONCLUSION

The consumption of UPFs was positively associated with WC and atherogenic blood lipids. However, increased intakes of fiber and unsaturated fats were also found in those consuming more UPFs, which was not expected. These findings offer insights into an understudied population and warrant further research.

Association between ultra-processed food intake and risk of colorectal cancer: a systematic review and meta-analysis

Background

Although some epidemiological studies have shown a positive relationship between high intake of ultra-processed food (UPF) and risk of colorectal cancer (CRC), the results remain inconsistent. Therefore, we conducted this systematic review and meta-analysis to clarify the association between UPF intake and CRC risk.

Methods

PubMed/MEDLINE, Web of Science, EMBASE, China National Knowledge Infrastructure (CNKI) and Wan fang databases were used to search the relevant studies published up to February 2023. The summary relative risks (RRs) with the corresponding 95% confidence intervals (CIs) were estimated by comparing the highest category vs. the lowest category of UPF intake, using the random-effects models (DerSimonian-Laird method). Heterogeneity between studies was explored using the Cochran's Q test and I-square (I²). Publication bias was assessed by examining the funnel plots, and quantified by Begg's or Egger's tests.

Results

A total of seven articles (three cohort and four case-control studies), involving 18,673 CRC cases and 462,292 participants, were included in our study. Combining nine effect sizes from seven articles, an increased risk of CRC was shown in the highest compared with the lowest category of UPF intake (RR = 1.26; 95%CI:1.14-1.38, p < 0.0001). Subgroup analyses showed a positive association between UPF intake and CRC risk in case-control studies (RR = 1.41; 95%CI: 1.22-1.63, p < 0.0001). When we conducted analyses separately by study area, there was a significant association between UPF intake and CRC risk in developed countries (RR = 1.20; 95%CI: 1.11-1.30, p < 0.0001).

Conclusion

Our results show that high UPF intake is significantly associated with a higher risk of CRC, in the absence, however, of a dose-response association. Further studies in particular of large prospective cohort studies are necessary to confirm these results.

Association between ultra-processed foods and risk of cancer: a systematic review and meta-analysis

Background

Despite increasing evidence that has shown the association of ultra-processed foods (UPFs) with cancer risk, the results remain inconclusive. We, therefore, conducted the meta-analysis to clarify the association by including recently published studies.

Methods

A comprehensive search was conducted in PubMed, Embase, and Web of Science to identify all relevant studies from inception to January 2023. To pool data, fixed-effects or random-effects models were used where appropriate. Subgroup analyses, sensitivity analyses, and publication bias tests were performed.

Results

A total of 13 studies (4 cohort studies and 9 case-control studies) were included in the analysis, with a total of 625,738 participants. The highest UPFs consumption was associated with increased risk of colorectal cancer (OR = 1.23, 95% CI: 1.10-1.38), colon cancer (OR = 1.25, 95% CI: 1.14-1.36), and breast cancer (OR = 1.10, 95% CI: 1.00-1.20) but not rectal cancer (OR = 1.18, 95% CI: 0.97-1.43) and prostate cancer (OR = 1.03, 95% CI: 0.93-1.12). In addition, the subgroup analyses showed that a positive association between UPFs consumption and colorectal cancer was observed among men (OR = 1.31, 95% CI: 1.15-1.50), whereas no significant association was observed among women (OR = 1.10, 95% CI: 0.94-1.29).

Conclusion

The present meta-analysis suggests that high UPFs consumption is associated with a significantly increased risk of certain site-specific cancers, especially the digestive tract and some hormone-related cancers. However, further rigorously designed prospective and experimental studies are needed to better understand causal pathways.

Association between ultra-processed foods intake with lipid profile: a cross-sectional study

The purpose of this cross-sectional study was to examine the association between ultra-processed foods (UPFs) intake and lipid profile in Iranian people. The study was performed on 236 individuals with the age range of 20-50 years in Shiraz, Iran. Food intakes of the participants were evaluated using a 168-item food frequency questionnaire (FFQ) which was previously validated in Iranian populations. In order to estimate the ultra-processed foods intake, classification of NOVA food group was used. Serum lipids including total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C) were measured. The results showed that mean of age and body mass index (BMI) of the participants were 45.98 years and 28.28 kg/m², respectively. Logistic regression was used to evaluation the relation between UPFs intake and lipid profile. Higher UPFs intake was associated with increased OR of TG and HDL abnormality in both crude (OR 3.41; 95% CI 1.58, 7.34; P-trend = 0.001 and OR 2.99; 95% CI 1.31, 6.82; P-trend = 0.010) and adjusted models (OR 3.69; 95% CI 1.67, 8.16; P-trend = 0.001 and OR 3.38 95% CI 1.42, 8.07; P-trend = 0.009). But, there were no association between UPFs intake and other indices of lipid profile. Also, we found significant associations between UPFs intake and dietary nutrient profiles. In conclusion, UPFs consumption could worsen the nutritional profile of the diet and lead to negative changes in some indices of the lipid profile.

The Rise of Gastrointestinal Cancers as a Global Phenomenon: Unhealthy Behavior or Progress?

The overall burden of cancer is rapidly increasing worldwide, reflecting not only population growth and aging, but also the prevalence and spread of risk factors. Gastrointestinal (GI) cancers, including stomach, liver, esophageal, pancreatic, and colorectal cancers, represent more than a quarter of all cancers. While smoking and alcohol use are the risk factors most commonly associated with cancer development, a growing consensus also includes dietary habits as relevant risk factors for GI cancers. Current evidence suggests that socioeconomic development results in several lifestyle modifications, including shifts in dietary habits from local traditional diets to less-healthy Western diets. Moreover, recent data indicate that increased production and consumption of processed foods underlies the current pandemics of obesity and related metabolic disorders, which are directly or indirectly associated with the emergence of various chronic noncommunicable conditions and GI cancers. However, environmental changes are not restricted to dietary patterns, and unhealthy behavioral features should be analyzed with a holistic view of lifestyle. In this review, we discussed the epidemiological aspects, gut dysbiosis, and cellular and molecular characteristics of GI cancers and explored the impact of unhealthy behaviors, diet, and physical activity on developing GI cancers in the context of progressive societal changes.