If you need (yet another) reason to avoid processed foods – like chicken nuggets, soda, sweetened drinks and packaged breads and desserts – a recent study shows that people that consume these foods have an increased risk of developing cancer. While it’s been known for a long time that ‘junk food’ is packed with calories and contains very little in the way of healthy nutrients, this study shows processed foods carry an extra risk of cancer, above and beyond being nutritionally bad for you.

This study was published in the British Medical Journal and was conducted on over 100,000 adults using questionnaires to collect data on over 3300 different food items. The results showed that a 10% increase in ultra-processed foods in the diet was associated with a significant increase of greater than 10% in risks of overall and breast cancer. Ultra-processed foods include:

  • Mass produced packaged breads and buns (i.e, stuff in vending machines, most of the breads, sweets, buns, desserts found in the grocery store)
  • Sweet and savory packaged snacks (i.e., trail mixes, sugar added packaged snacks)
  • Packaged confectionery and desserts (i.e., packaged cakes, cupcakes, sweets, pastries, etc.)
  • Sodas and sweetened drinks
  • Meat balls, poultry (chicken) and fish nuggets (i.e., chicken/fish nuggets/fingers, fish sticks, etc.)
  • Other reconstituted meat products containing preservatives other than salt (i.e., nitrites) (i.e., packaged luncheon/deli meats)
  • Instant noodles and soups (i.e., ramen noodles/soups, powdered soup mixes, etc.)
  • Frozen or shelf-stable ready meals (i.e., frozen dinners, TV dinners, packaged lunches/dinners)
  • Food products made mostly or entirely from sugar, oils and fats, hydrogenated oils, modified starches (i.e., snack chips/products, candy, sweets, etc.)
  • Packaged fried foods (i.e., potato chips, snack chips, packaged fried chicken/fish, etc.)
  • Packaged foods containing flavoring agents (natural and/or artificial flavors), emulsifiers, humectants, non-caloric sweeteners and food colors (i.e., anything that contains FD&C…, artificial colors, artificial flavors, artificial sweeteners, etc.)

These ultra-processed foods are characterized by lower nutritional quality and contain additives, substances from packaging in contact with food, and compounds formed during production, processing, and storage that make them potential carcinogens. It’s well documented that these processed foods have a higher content of total fat, saturated fat and added sugar and salt, along with a lower fiber and nutrient (vitamin and mineral) density than unprocessed foods. However, beyond the nutritional deficits in these food-like products, many carcinogenic chemicals are made during heat treatment of processed foods (including acrylamide, heterocyclic amines, and polycyclic aromatic hydrocarbons) as a result of the Maillard reaction (which browns bread and provides sweetness, texture and color to processed goods). In addition, the packaging of ultra-processed foods often contains chemicals and compounds that can be transferred into the food-product, including carcinogenic compounds and known endocrine disruptors like bisphenol A. Finally, these processed foods often contain legal, but controversial food additives,such as sodium nitrite in processed meats that have been proven to be carcinogenic in animal and cellular models. Combined, these characteristics are likely the culprits behind the increased cancer risk associated with consuming these food-like products.

This should get your attention, as these types of foods make up the majority of most people’s diets. A 2016 study found that ultra-processed foods make up almost 60% of the average American diet. A 2017 study found that these food-like products make up 50% of the Canadian diet and they make up more than 50% of the UK diet.

Science is showing us what most of us already know – these processed food-like substances are not good for you. This is obviously not a big enough motivator for most people. Hopefully, the knowledge that not only are they not good for you, but that they can directly cause cancer and other diseases over time will be enough of a motivator to eliminate them from the diet.