Study links ultra-processed food consumption with higher cardiovascular risk

By Dr. Chinta SidharthanReviewed by Susha Cheriyedath, M.Sc.Feb 21 2024

In a recent study published in the journal EClinicalMedicine, a team of Chinese researchers conducted a systematic review and meta-analysis to understand the dose-response relationship between increased consumption of ultra-processed foods and the risk of cardiovascular events.

Study: Ultra-processed food consumption and risk of cardiovascular events: a systematic review and dose-response meta-analysis

Background

Diet is considered one of the major modifiable risk factors of cardiovascular disease, which continues to be a serious public health concern and the leading cause of death. Furthermore, despite strong evidence for and various guidelines recommending whole grains and unprocessed foods for heart health, the growing food processing industry and the fast-paced nature of modern lifestyles have increased the dependence on and consumption of ultra-processed foods.

Ultra-processed foods are made using ingredients already processed to a large extent and contain synthetic food additives such as preservatives, food colors, and stabilizers. The consumption of ultra-processed foods is also known to differ across age groups and countries, with younger individuals in the United States having the highest consumption of ultra-processed foods. Increased intake of ultra-processed foods, which include foods and beverages with added sugars, refined grains, and processed meats, also results in significant non-adherence to the Mediterranean diet, which has been recommended for cardiovascular health.

About the study

In the present study, the researchers investigated the dose-response relationship between the consumption of ultra-processed foods and the risk of cardiovascular events by conducting a systematic review and meta-analysis of observational studies on the association between ultra-processed food consumption and cardiovascular events such as coronary heart disease and cerebrovascular disease.

The review did not include any animal model studies; only those published in English were considered. Furthermore, all case-control, cohort, and cross-sectional observational studies that included participants above the age of 18 years, with ultra-processed food consumption as the examined exposures, were included in the review.

The included studies were also required to follow the Nova food classification system, with examined outcomes being cardiovascular events such as stroke, myocardial infarction, coronary intervention such as stent thrombosis, transient ischemic attack, peripheral vascular intervention, acute heart failure, hospitalization due to angina, or mortality due cardiovascular disease. Studies that did not have effect estimates in the form of hazard ratios or odds ratios were excluded.

Data extracted for the meta-analysis included the tools used for dietary assessments, the number of years of follow-up, outcomes and how they were defined, the covariates that were considered during the multivariate analyses, and effect size and evaluation criteria for ultra-processed food consumption.

The extracted data were used to conduct a meta-analysis and dose-response examination using different units of consumption of ultra-processed foods such as weight, energy proportion, and servings. A stratified analysis was also carried out to evaluate the outcomes of cardiovascular events and cerebrovascular disease, adjusted for factors such as country of study, dietary quality, method of dietary assessment, publication year, duration of follow-up, and sample size. The relative risk of cardiovascular events was also estimated for each unit increase in ultra-processed food consumption.

Results

The study found that consumption of ultra-processed foods had a linear relationship with increasing risk of cardiovascular events. Furthermore, daily consumption of ultra-processed foods measured in terms of energy proportion and serving showed a positive correlation with coronary heart disease. However, the risk of cerebrovascular disease was not found to be associated with the consumption of ultra-processed foods.

 A 10% increase in weight proportion of daily consumption of ultra-processed foods was found to increase the risk of cardiovascular events by 1.9%, and an extra serving of ultra-processed food was found to increase cardiovascular event risk by 2.2%. Similarly, a 10% increase in terms of energy proportion in the daily intake of ultra-processed foods corresponded to a 1.6% increase in the risk of cardiovascular events.

The meta-analysis included over a million cases, of which more than 50,000 were of cardiovascular events. Given the large sample size, which covered data from 22 cohorts, the scientists believe that the findings were well supported. The review also included numerous studies that reported no or opposite associations between ultra-processed food consumption and the risk of cardiovascular events, decreasing the bias risk in the meta-analysis findings.

Conclusions

Overall, the findings highlight the detrimental effects of ultra-processed foods in increasing the risk of cardiovascular disease. Furthermore, the dose-response analysis indicated an increase in cardiovascular event risk based on increased ultra-processed food consumption in terms of energy proportion, weight, and servings. These results emphasize the need for more public health initiatives to educate people about the increasing risk of cardiovascular disease due to unhealthy diets.