Do you eat a lot of processed foods? Your answer would probably depend upon how processed foods are defined. One of AICR’s cancer prevention recommendations is to limit the amount of fast and processed foods that you eat. You probably know that chips, frozen pizza, brownies and hot dogs are considered processed. But what about that canned tuna, bread or boxed pasta? And what exactly does “a lot” mean anyway?
Scoring how processed foods are categorized was one of the more challenging tasks, according to the authors of a new paper that proposes a standardized scoring system for the AICR/WCRF’s cancer prevention recommendations. The paper, published in Nutrition, aims to improve comparisons between studies and ultimately, help to better understand how adhering to the recommendations links to cancer risk across various populations.
You can read more about the paper here. It was led by researchers at the National Cancer Institute (NCI) in collaboration with experts at AICR, World Cancer Research Fund (WCRF), and in Europe.
Processing – the adding and more adding
Many foods are processed, everything from frozen peas to a cake mix, but the extent and type of processing can have dramatic effects on the healthfulness of those foods. AICR recommends limiting consumption of fast-foods and processed foods high in sugars, fats and starches. These are the foods that cause weight gain, overweight and obesity, which is a cause of 12 cancers.
“It’s important to remember that not all foods with some processing are unhealthy. The AICR recommendation focuses on foods considered highly or ultra- processed,” says Alice Bender, MS, RDN, the Director of Nutrition Programs at AICR and one of the study authors. Canned and frozen vegetables, for example, are classified as minimally processed, and these are part of a cancer-preventive diet.
“In general, ultra-processed foods are those that have been changed in ways that remove or diminish nutrients like fiber and vitamins. Then, fats, sugar and salt are added which turn an otherwise healthy food into a high-calorie, low-nutrient food putting you at risk for hypertension, weight gain and unhealthy fats in your blood,” adds Bender.
That’s why a box of whole wheat pasta or brown rice – which keeps its natural fiber and nutrient content – would be considered minimally processed. But a box of flavored or seasoned white rice with added salt, fats, or sugars would be categorized as ultra-processed. Homemade mashed potatoes are more processed than a plain baked potato. However, a potato chip, with large amounts of added fat from the deep fat fryer and a large portion of salt, that is an ultra-processed food.
“You can compare the fat, saturated fat, and sodium to the percent Daily Value (%DV) on the Nutrition Facts Label: anything 5% or less is low; a number 20% or above is high,” says Bender. “Added sugars don’t have a Daily Value, but keep in mind that 4 grams of added sugar equals 1 teaspoon of sugar. The Centers for Disease Control and Prevention (CDC) recommends consuming less than 10% of total calories from added sugar – less than 10 teaspoons for a 1600 calorie diet.”
The AICR recommendations purposefully take a food-based approach so the first decision for standardizing the AICR recommendation was to focus on whole foods, not food components such as sugars and fats, says Jill Reedy, Ph.D., M.P.H., R.D, a Program Director in NCI’s Division of Cancer Control and Population Sciences (DCCPS) and senior author of the paper.
Given the challenges of defining fast or processed foods, the authors decided to adapt a well-known food classification tool called NOVA – not an acronym. NOVA assigns foods to four categories, from unprocessed to ultra-processed. Incorporating the NOVA classification system into the AICR Score required sugar-sweetened beverages and processed meat (both considered “group 4” – ultra processed) to be excluded from the analysis of ultra-processed food intake since these are addressed by other specific AICR recommendations.
The next step was to define three equally-sized groups of ultra-processed food intake within the population – low, middle and high – a process that spurred a lot of discussion among the authors. The group assignment is based upon the percent of daily calories, and the authors recognized that depending upon the country, the low or high will vary, said Reedy. “We know that different countries have different levels of processing. If you look at Brazil, for example, the proportion of these foods the population consumes is lower than what we have in the United States.”
Setting the three categories allows studies to divide their population between these groups no matter what population they’re from, she said. This approach also accounts for variation in how each study collects data, where food questionnaires might ask many or few questions about ultra-processed foods.
Lowering your score
This is a starting framework, note the authors, future work is planned. While the research is continuing on how to study and score fast and processed food intake, consider how much of these foods you eat.
If you’re like the average American, chances are that too much of your daily diet comes from ultra-processed foods. A study last year found that about 60 percent of an average American’s calories come from ultra-processed foods. In fact, Americans’ consumption of ultra-processed foods shows no signs of slowing. Over the course of this study, from 2007 to 2012, American consumption of these foods increased slightly each year. These ultra-processed foods included sugary drinks, packaged breads, chicken nuggets and instant noodle soups.
“If you’re used to purchasing and eating a lot of boxed and frozen highly processed foods, begin to look for ‘convenience foods’ that are closer to their nutrient rich origin,” advises Bender. “For example, instead of a frozen fried chicken meal, purchase a prepared roast chicken, frozen brown rice and frozen mixed vegetables.”
“Remember, what’s important is to start making changes. Find new ways to reduce ultra-processed foods by substituting minimally-processed foods so you can enjoy the flavors and textures of less processed foods and you’ll be creating a diet with more cancer-fighting punch,” says Bender. “The occasional small fries or rich dessert can fit if most of the time your plate reflects mostly whole foods like vegetables, whole grains, fruit with small to moderate amounts of animal foods.”
Want some ideas on how to eat healthier – and save money? Alice shares a few here.