A study from Italy found that eating a lot of processed foods is associated with increased risk for suffering a heart attack in people who have heart disease, and dying from heart disease, even if that person followed the plant-based Mediterranean diet and all the other rules for preventing and treating heart disease (European Heart Journal, Nov 30, 2021). Researchers followed 1,171 Italians who already had heart disease for more than 10 years and found that those who ate the most ultra-processed foods had a 70 percent increased risk for a second heart attack or stroke and a 40 percent increased risk of dying from any cause. This study classified diet by the NOVA system, that rated foods by the degree of processing rather than by the usually-measured differences such as a diet high in meat or sugar, or low in fruits and vegetables. Ultra-processed food is defined by the processes used for its preparation and storage, not on its nutritional content.
Earlier data from the NHANES study showed that in North America, almost 60 percent of calories and more than 90 percent of the sugar are consumed in “ultra-processed foods” (BMJ Open, March 9, 2016;6(3)). These researchers analyzed the diets of more than 9000 people and found that on average, 20 percent of the total calories they ate came from sugar in ultra-processed food products. The percentage of sugar was much higher in those who ate the most ultra-processed foods. See my report on Hidden Sugars.
Processing techniques may include:
• adding preservatives to prolong shelf life
• canning or bottling, which often involves adding sugar or salt, and exposes the foods to metals and plastics
• using artificial flavorings and colorings to imitate those found in nature
• pre-cooking at high temperatures, such as frozen fried foods, which can form known carcinogens
• grinding dry foods such as whole grains into flour to make bread and other bakery products, pasta and most dry breakfast cereals
When grains are ground into flour, fiber and other nutrients are usually removed, and foods made from flour increase the rise in blood sugar that damages your arteries.
• Ultra-processed foods are made by removing nutrients such as fiber, vitamins, minerals or antioxidants and adding dyes, preservatives, antioxidants, anticaking agents, flavor enhancers, sugars, fats, salt and other ingredients. Ultra-processed foods include soft drinks, fruit drinks, most dry breakfast cereals, frozen pizzas, frozen meals and entrees, breads, cakes, pies, cookies, snack bars including power bars, diet bars and energy bars, candy, crackers, salty snack foods such as potato chips, corn chips and pretzels, processed meats including those made from poultry or seafood, instant soups and noodle bowls, salad dressings and many others. The authors of the NHANES study define ultra-processed foods as “Formulations of several ingredients which, besides salt, sugar, oils, and fats, include . . . flavors, colors, sweeteners, emulsifiers and other additives used to imitate sensorial qualities of unprocessed or minimally processed foods . . . or to disguise undesirable qualities of the final product.”
• Unprocessed foods are are whole foods that are recognizable parts of plants (leaves, stems, roots, fruits, seeds) or animals (cuts of meat, poultry or seafood, eggs).
• Minimally processed foods are parts of plants or animals that have been cleaned and packaged, and may have been chopped or otherwise reduced to small particles; blanched or pre-cooked (but not browned); and/or frozen or dried. Non-flavored dairy products including cheeses and plain yogurt, and simple prepared foods such as pastas or fresh-baked bread can also be considered to be minimally processed. If the package has a very short list of ingredients (1-4), the food is probably minimally processed, but check for added sugars.
A healthful diet involves more than just eating lots of fruits, vegetables, whole grains, beans, nuts and other seeds. It also involves eating these foods as they come to you in nature, so you can recognize the parts of plants or animals. Eating a lot of foods that come in packages increases risk for that food being altered in ways that can harm you. I agree with the authors of these studies who recommend cutting way back on ultra-processed foods and getting most of your calories from nutrient-rich unprocessed or minimally processed foods.