Ultra-Processed Foods Increase Cancer Risk

Two new large research studies found that ultra-processed foods can increase the risk for colorectal cancer, premature death, and heart disease.
The first study found men who ate in the top fifth of ultra-processed food consumption had a 29% higher risk of developing colorectal cancer.
The second study found that those who ate nutrient-poor foods and ultra-processed foods had a higher risk of developing chronic disease or premature death, especially from cardiovascular disease.

Eating healthy is essential for feeling your best. But, now, two large research studies are showing just how detrimental eating nutrient-poor foods can be. The studies suggest that eating ultra-processed foods can increase the risk of cancer and even lead to heart disease and premature death.

Specifically, researchers saw a link between ultra-processed foods and cancer in men, and heart disease or premature death for both men and women.

What are ultra-processed foods?
Highly-processed or ultra-processed foods include foods that have undergone extensive processing. These foods include chemicals such as artificial sweeteners, colours, and flavours. They are usually ready-to-eat and don’t need much preparation, such as soft drinks, cakes, biscuits, frozen ready-meals, ice creams and chips.

It’s important to note that almost everything we eat (unless we grow it ourselves) is processed—and processed foods have become integral in helping many make the most of their busy lives.  Unprocessed or minimally processed foods are foods in their whole form (like apples, bananas, and spinach) that have vitamins and nutrients when consumed.

Processed foods, on the other hand, are foods that have additional ingredients like added salt, oil, sugar, or other additives, like canned fish, fruits in syrup, or bread. And, as mentioned above, ultra-processed foods take this a bit further with added sugar, salt, fat, and artificial ingredients.

What the studies say
The first study published in The British Medical Journal found men who ate a lot of ultra-processed foods and men and women who ate some specific ultra-processed foods were associated with an increased risk of colorectal cancer. Researchers looked at data from over 46,000 men from the Health Professionals Follow-up Study and nearly 160,000 women from two different cohorts of the Nurses’ Health Study. Participants had provided dietary information and had no cancer diagnoses at the beginning of the study.

After 24 to 28 years of following up, researchers found 3,216 cases of colorectal cancer in both men and women. Compared to the men in the lowest fifth of ultra-processed food consumption, men in the highest fifth had a 29% higher risk of developing colorectal cancer. These men were also more likely to be current smokers, have higher body mass indexes, lower consumption of alcohol, lower level of physical activity, and consume a diet lower in dietary fibre, folate, calcium, vitamin D, and whole grains with more fat, added sugar, and processed meats. The association remained the same after researchers considered these factors. Interestingly, researchers did not find a connection between overall ultra-processed food and the risk of colorectal cancer for women. More research is needed to determine why this is.

The study did find that those who had ultra-processed foods that included more ready-to-eat products of meat, poultry, and seafood (like bacon, fish sticks, or hotdogs) and sugar-sweetened beverages among men and ready-to-eat/heat-mixed dishes among women also had an increased risk of colorectal cancer.

A second study and analysis published in The British Medical Journal assessed the diets of more than 22,000 people in the Molise region of Italy and their mortality risk after 14 years of follow-up. Researchers analysed two food classification systems—the Food Standards Agency Nutrient Profiling System (FSAm-NPS index) used for colour-coding nutritional scores on labels and the NOVA scale, an evaluation of the degree of food processing.

We recommend to set specific nutrition goals:

• Eat more whole and minimally processed foods like seeds, legumes, grains, fruits, and vegetables.
• Work toward eating a plant-based diet. A good start toward eating a plant-based diet would be to fill two thirds of your plate with colourful fruits, vegetables and whole grains. Fill the remaining third of your plate with fish, poultry, lean meats, low-fat dairy products, or plant-based proteins and legumes (e.g. black beans, chick peas, lentils, tofu, hummus), nuts, seeds.
• Go meatless when you can. Otherwise, limit cooked red meat to no more than three portions per week (small portion)
• Try to avoid processed meats such as cold cuts/sandwich meats, bacon, hot dogs and chorizo, ham, pastrami, pepperoni, and salami.
• Limit “energy dense foods.” These are foods that are high in added sugar and fat, and include French fries, potato and other chips, pastries, donuts, candy, and sugar-sweetened beverages.  Enjoy fresh fruit and fruit infused water instead as a snack.
• Choose whole grain breads, pasta, and cereals such as oats, barley, and brown rice. Use these in place of foods made from refined flour like white bread, pasta, low fibre breakfast cereals, and white rice.

Aim for a healthy weight.
Avoid inactivity. With the approval of your physician aim for a minimum of 30 minutes of exercise five days per week.

The study found that those who ate nutrient-poor foods and ultra-processed foods had a higher risk of developing chronic disease or premature death, especially from cardiovascular disease. Researchers estimated those with the least healthy diet based on the FSAm-NPS index had a 19% higher risk of death from any cause and a 32% risk of death from cardiovascular disease compared to those with the healthiest diet. Additionally, those with the least-healthy diet based on the NOVA scale had a 19% and 27% higher risk for all-cause and cardiovascular mortality respectively.

While researchers considered the diet scores, nutrition patterns, sex assigned at birth, and race of participants, they didn’t consider social determinants of health—a deterrent of this study, per Feller. Socioeconomic background and education can play a major part in a person’s overall health and access, she says.

The bottom line
The key takeaway from the research is that scientists were really looking at Western patterns of eating a highly processed-food diet including things with additives, higher amounts of sugar, salt, and saturated and synthetic fats instead of foods with nutrients.

We’ve long known ultra-processed foods should be consumed sparingly in the diet. Previous research from earlier this year found that ultra-processed foods can negatively impact cognitive function, and a recent study linked charcuterie with an increased risk for colon cancer. Other research found eating a little over five ounces of processed meat per week may put you at greater risk for heart disease and early death, and additional research found sugary drinks can spike the risk of colorectal cancer in young people.