A new large-scale comprehensive review of epidemiological meta-analyses strengthens the idea that ultra-processed foods negatively impact most aspects of human health [1].

Is it even food?

Much has been said about the dangers of ultra-processed foods, but could another study add something new? The authors of this new paper, published in the prestigious journal BMJ, say that “no comprehensive comprehensive review provides a broad overview and assessment of the existing meta-analytic evidence on the health effects of ultra-processed foods. “I don’t do that,” he said, trying to bridge this gap. We scrutinized 45 existing meta-analyses covering a total of approximately 10 million participants.

As the accompanying editorial makes clear, ultra-processed foods are more than simply processed foods; according to the established NOVA model, they include “chemically manipulated foods such as modified starches, sugars, oils, fats, and protein isolates. When adding whole foods, flavorings, colorants, emulsifiers, thickeners, and other additives can be used in combination to make them delicious and appealing. I will make it a thing. ”

Essentially, advanced processing completely rearranges food, creating products that do not exist in nature and are incompatible with the gastrointestinal system shaped by millions of years of evolution. Ultra-processed foods are often stripped of important nutrients such as flavanols and added fat, salt, and sugar to make them more appealing to us.

71% of results are affected

This study yielded some expected results and some surprising results. High intakes of ultra-processed foods were associated with a 21% increase in all-cause mortality and a 50% increase in cardiovascular disease-related mortality.

Proven in clinical trials [2], consuming ultra-processed foods increases the risk of obesity and metabolic disorders. This was confirmed by this study. Eating large amounts of ultra-processed foods increased the likelihood of obesity by 55%, metabolic syndrome by 25%, and type 2 diabetes by 40%. Even just a 10% increase in ultra-processed food consumption was associated with negative health outcomes, including a 12% increase in the likelihood of diabetes. In total, we found direct associations with 71% of the health outcomes analyzed.

One of the strongest associations observed was with various aspects of mental health, including sleep quality, anxiety, and common mental health disorders. However, this may be due to reverse causation, as depression and other mental illnesses can lead to higher intakes of unhealthy foods.

However, the study showed limited associations between ultra-processed foods and outcomes such as asthma, nonalcoholic fatty liver disease, and hypertension.

No evidence of cancer risk

Another surprise was that there was little or no association between ultra-processed foods and cancer mortality or incidence. This is interesting because a number of early studies have shown this association. [3]. The evidence regarding ultra-processed meat in particular is considered so strong that it became one of the few food categories designated as a known carcinogen by the World Health Organization.Obesity is a major risk factor for cancer [4]Therefore, ultra-processed foods should influence cancer outcomes, at least through obesity.

This does not mean that the link between ultra-processed foods and cancer does not exist. One possible explanation is that the study did not differentiate between types of ultra-processed foods, which may have blunted the effects of some of these types (such as processed meat).

Population studies can be highly heterogeneous and difficult to interpret, and can only show correlations, not causation. Even if there’s no link to cancer, there are still plenty of reasons to avoid ultra-processed foods completely. Read our 2022 interview with Professor Albert László Barabási for his exciting take on ultra-processed foods.

Our comprehensive review provides a comprehensive overview and assessment of the evidence regarding the association between dietary exposure to ultra-processed foods and various adverse health effects. Our review included 45 separate pools across seven health parameters related to mortality, cancer, psychiatric, respiratory, cardiovascular, gastrointestinal, and metabolic health outcomes, including a total of 9,888,373 participants. analysis was included. Across the integrated analysis, greater exposure to ultra-processed foods increases the risk of adverse health effects, whether measured by more or less consumption, additional servings per day, or 10% more food. was consistently associated with higher levels (71% of outcomes).

literature

[1] Lane MM, Gamage E, Du S, et al (2024) Exposure to ultra-processed foods and adverse health effects: a comprehensive review of epidemiological meta-analyses. BMJ; 384:e077210.

[2] Hall, K. D., Ayuketah, A., Brychta, R., Cai, H., Cassimatis, T., Chen, K. Y., … & Zhou, M. (2019). Ultra-processed diets cause excess caloric intake and weight gain: a randomized controlled trial in hospitalized patients with ad libitum access to food. Cell Metabolism, 30(1), 67-77.

[3] Wang, L., Du, M., Wang, K., Khandpur, N., Rosato, SL, Drouin-Chartier, JP, … & Zhang, FF (2022). Association between ultra-processed food intake and colorectal cancer risk among men and women: Results from three prospective US cohort studies. bmj, 378.

[4] Pati, S., Irfan, W., Jameel, A., Ahmed, S., and Shahid, R. K. (2023). Obesity and cancer: An updated overview of epidemiology, etiology, outcomes, and management. Cancer, 15(2), 485.