Diet is a powerful tool to prevent and fight chronic disease. In regard to cancer, what we eat has the potential to modify our genes, either improving our health or leaving us susceptible to developing cancer.
Processed food consumption is at an all-time high, while intake of whole foods such as fruits and vegetables is not common. Approximately 60% of calories consumed by adults in the U.S. come from processed foods. Examples of processed foods include frozen dinners, pastries, boxed meals and hot dogs. Many foods are processed for purposes of convenience, to increase shelf life or to increase palatability (texture, taste and appearance). This is done using food additives, artificial flavorings, colors, sweeteners and preservatives.
Interestingly, a recent study led by researchers from the International Agency for Research on Cancer (IARC) found that for every 10% increase in consumption of processed foods, there is a 2% increased risk of cancer occurrence and a 19% increased risk of ovarian cancer. Causation was not identified but other research has led to suspicions for food additives, etc. to be linked to hormone disruption and oxidation within the body.
The IARC has a classification system in which they review current research and can organize substances that may cause cancer or be carcinogenic.
Class 1 substances: Known to cause cancer in humans. Examples: smoking/alcohol intake.
Class 2A substances: Probable to cause cancer in humans. Examples: nitrates/nitrites (found in processed meats).
Class 2B substances: Possible to cause cancer in humans. Examples: titanium dioxide (found in sauces, icings, candies, toothpaste and chewing gum).
You might be thinking that if these classifications are in place, why do we still have these additives in foods? The Food and Drug Administration (FDA) maintains a list of 3,000+ ingredients used in processed foods. The FDA requires that a food additive be proven as safe for its intended use unless it is already “generally recognized as safe” by qualified experts with scientific training and experience or meets other exclusions as outlined by section 201(s) of the Federal Food and Drug and Cosmetic Act.
Even though the FDA monitors food additives, it is still a good idea to limit intake of these ingredients to promote good health. Besides limiting potential cancer risk, lowering processed food intake is also good for promoting healthy weight and lowering
blood pressure and blood sugar.
Here are simple ways you can be an informed shopper and limit processed foods:
- Follow a plant-based diet. Focus on eating whole fruits, vegetables, whole grains and high-quality animal proteins.
- Packaged fruits and vegetables are okay to use when fresh is not available.
- Look for foods with “no added salt” or “low sodium” on the label. In general, try to limit consumption of sodium to 2,000 milligrams daily.
- Look for foods with no added sugars. Make sure to check the ingredients list, as sugar can have many different names (e.g., high fructose corn syrup, dextrose, fructose, corn syrup, malt syrup, honey, sweetener).
- Become aware of potentially harmful food additives. Cspinet.org is a great resource to learn more.
- Shop the outside perimeter of the grocery store versus shopping in the aisles.
- Look for foods with short ingredient lists — the fewer the ingredients in the food, the less processed.
- Enjoy the art of cooking. This allows you to better control the ingredients in your food (e.g., prepare a homemade pizza using ingredients in your pantry instead of buying frozen pizza).
- Bischoff NS, et al. Possible Adverse Effects of Food Additive E171 (Titanium Dioxide) Related to Particle Specific Human Toxicity, Including the Immune System. Int J Mol Sci. 2020 Dec 28;22(1):207. doi: 10.3390/ijms22010207.
- "Overview of Food Ingredients, Additives & Colors," U.S. Food and Drug Administration, accessed February 1, 2023, https://www.fda.gov/food/food-ingredients-packaging/overview-food-ingredients-additives-colors.
- Chang K, et al. Ultra-processed food consumption, cancer risk and cancer mortality: a large-scale prospective analysis within the UK Biobank. EClinicalMedicine. 2023 Jan 31;56:101840. doi: 10.1016/j.eclinm.2023.101840. eCollection 2023 Feb.
- Martínez Steele E, et al. Ultra-processed foods and added sugars in the US diet: evidence from a nationally representative cross-sectional study. BMJ Open. 2016 Mar 9;6(3):e009892. doi: 10.1136/bmjopen-2015-009892.
- Smith MT, et al. Key Characteristics of Carcinogens as a Basis for Organizing Data on Mechanisms of Carcinogenesis. Environ Health Perspect. 2016 Jun;124(6):713-21. doi: 10.1289/ehp.1509912. Epub 2015 Nov 24.