Consumption of Ultra Processed Foods and Cancer

Liberal consumption of ultra-processed foods increase the risk of obesity, diabetes, and heart disease. How do they  affect one’s cancer risk?

Convenience and taste have made ultra processed foods (UPFs) a welcome part of the diet for many people. Ultra-processed foods are convenient as they are durable and ready to eat in a world where busy people have less and less time for food preparation.  UPFs are industrially manufactured foods with added ingredients or additives (e.g. modified starch, hydrogenated oils) that are typically not available for food preparation at home or at artisan restaurants or companies. They are generally tasty. Examples are soft drinks, sweet or savory packaged snacks, processed meat, prepared frozen or shelf-stable dishes, and sweetened breakfast cereals.¹ 

Even though they are convenient and tasty, UPFs are generally nutritionally inferior and are higher in energy, total and saturated fats, salt, and free sugars, and lower in fiber and several micronutrients. Moreover, high levels of processing results in degradation of food health potential and deterioration of nutrient bioavailability and bioaccessibility.²

Which Cancers?

Research is establishing the fact that eating UPFs have significant positive association with several cancers like colorectal cancer, breast cancer, and pancreatic cancer. Some association was seen between UPF ingestion and chronic lymphocytic leukemia and central nervous system tumors.³

Research found that increased consumption of UPF elevated the risk of multi-morbidity of cancer and cardio-metabolic diseases. It was also noticed that the associations were most notable for animal-based products and artificial sugar-sweetened beverages. At the same time ultra-processed breads and cereals or plant-based alternatives were not associated with risk.⁴

By How Much?

Specifically, every 10% increment in UPF content of diet was associated with an increased incidence of overall cancer by 2% and ovarian cancer by 19%. Every 10% increment in UPF consumption was associated with increased mortality of overall cancer by 6%, breast cancer by 16%, and ovarian cancer by 30%.⁵ A 10% increase in the proportion of ultra-processed foods in the diet was associated with a significant increase of greater than 10% in risks of breast and overall cancers. ⁶

Culprits in UFS

Emerging research has suggested that there are other factors that make UPFs contribute to adverse cancer outcomes.

Individuals that consume a diet rich in UPFs, according to an inpatient randomized controlled study,  tend to eat more calories and gain more weight when compared to an unprocessed diet.⁷ Obesity generates free radical production that damages the DNA, reduces the antioxidant defenses, dysregulates DNA repair,⁸ fuels inflammation, and suppresses the cancer-fighting mechanisms of the immune system. UPFs are usually high in sugar, calories, saturated or hydrogenated fat, salt, low in fiber, contain undesirable food additives–all of which disturb the diversity and healthy balance of the gut microbiome and contribute to ongoing inflammation if consumed regularly.

During processing carcinogenic-linked compounds may be created such as heterocyclic amines, polycyclic aromatic hydrocarbons, oxyhalides and haloacetic acids.⁹ Many UPFs contain the use of cosmetic additives (e.g. colors and taste enhancers) that can also contribute to one’s cancer risk.¹⁰

Generally, UPFs have controversial food additives in their ingredients. Ultra processing itself induces formation of neo-formed contaminants. The packaging may contain toxic contaminants that migrate from food packaging into the food itself. The higher use of artificial sweeteners to increase the taste of UPFs are associated with gut dysbiosis, increased risk of overall, breast, and obesity-related cancers.The higher intake of nitrate and nitrite from food additives was associated with increased risk of breast and prostate cancer, respectively. Titanium dioxide (TiO₂), which has been commonly used as a preservative to improve texture and as a coloring agent in UPFs, is now suspected as a carcinogen.

Higher dietary exposure of acrylamide, an industrial chemical formed during high-temperature cooking procedures, was found associated with an increased risk of ovarian and endometrial cancers. Phthalates and bisphenols are endocrine-disrupting chemicals commonly found in food storage and packaging materials. Higher urinary concentration of phthalates and bisphenols-F (analogue of the more regulated bisphenol-A) have been detected in individuals with higher UPF consumption.¹¹ BPA exposure may contribute to head and neck cancers.¹² Some emulsifiers promote inflammation.

Processed Meat and GI Cancer

A meta-analysis of 49 studies also showed an increased risk of gastric cancer among those with higher intakes of nitrites and nitrosamines ¹³ Additionally, there is evidence suggesting that processed meat intake increases colorectal cancer risk, with stronger associations for colon cancer.

Conclusions

Various mechanisms may explain the positive associations found between UPF consumption and the risk of adverse cancer outcomes. Dietary recommendations for cancer prevention emphasize the importance of nutritionally balanced diets involving greater consumption of whole vegetables, fruit, and whole grains. Lower, or better yet, eliminate the consumption of unprocessed red meat and avoid or eliminate processed mea.. Reduce sugar and sodium intake. Alcoholic drinks are strong risk factors for mouth, pharynx and larynx cancers; esophageal cancer; breast cancer; colorectal cancer; stomach cancer; liver cancer and kidney cancer.¹⁴

1. Cordova, Reynalda, et al. “Consumption of ultra-processed foods and risk of multi-morbidity of cancer and cardiometabolic diseases: a multinational cohort study.” The Lancet Regional Health–Europe 35 (2023). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10730313/ [↩]
2. Chang, Kiara, et al. “Ultra-processed food consumption, cancer risk and cancer mortality: a large-scale prospective analysis within the UK Biobank.” Eclinicalmedicine56 (2023). https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(23)00017-2/fulltext[↩]
3. Isaksen, Irja Minde, and Simon Nitter Dankel. “Ultra-processed food consumption and cancer risk: a systematic review and meta-analysis.” Clinical Nutrition(2023). https://www.sciencedirect.com/science/article/abs/pii/S0261561423000997[↩]
4. Cordova, Reynalda, et al. “Consumption of ultra-processed foods and risk of multi-morbidity of cancer and cardiometabolic diseases: a multinational cohort study.” The Lancet Regional Health–Europe 35 (2023). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10730313/ [↩]
5. Chang, Kiara, et al. “Ultra-processed food consumption, cancer risk and cancer mortality: a large-scale prospective analysis within the UK Biobank.” Eclinicalmedicine56 (2023). https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(23)00017-2/fulltext[↩]
6. Fiolet, Thibault, et al. “Consumption of ultra-processed foods and cancer risk: results from NutriNet-Santé prospective cohort.” bmj360 2018 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7451582/ [↩]
7. Hall KD, et al., Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake. Cell Metab. 2019 Jul 2;30(1):67-77.e3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7946062/[↩]
8. D’Amico AM, Vasquez KM: The multifaceted roles of DNA repair and replication proteins in aging and obesity. DNA Repair 2021, 99:103049[↩]
9. Pouzou JG, Costard S, Zagmutt FJ. Probabilistic assessment of dietary exposure to heterocyclic amines and polycyclic aromatic hydrocarbons from consumption of meats and breads in the United States. Food Chem Toxicol. 2018;114:361–74.[↩]
10. Kliemann N, A, et al.  Ultra-processed foods and cancer risk: from global food systems to individual exposures and mechanisms. Br J Cancer. 2022 Jul;127(1):14-20. doi: 10.1038/s41416-022-01749-y. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9276654/#CR60 [↩]
11. Chang, Kiara, et al. “Ultra-processed food consumption, cancer risk and cancer mortality: a large-scale prospective analysis within the UK Biobank.” Eclinicalmedicine56 (2023). https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(23)00017-2/fulltext[↩]
12. Emfietzoglou R, et al., Could the endocrine disruptor bisphenol-A be implicated in the pathogenesis of oral and oropharyngeal cancer? Metabolic considerations and future directions. Metabolism. 2019;91:61–9. [↩]
13.  Song P, Wu L, Guan W. Dietary nitrates, nitrites, and nitrosamines intake and the risk of gastric cancer: a meta-analysis. Nutrients. 2015;7:9872–95.[↩]
14. Kliemann N, et al. Ultra-processed foods and cancer risk: from global food systems to individual exposures and mechanisms. Br J Cancer. 2022 Jul;127(1):14-20. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9276654/ [↩]