Does eating ultra-processed foods increase cancer risk?

Everyone has heard of “processed foods”.  But now they talk about “ultra-processed” foods.  When teaching nutrition we did talk about why processed foods can be unhealthy but only recently has the term “ultra-processed” foods come into vogue.  In a previous blog post, Should You Avoid Ultraprocessed Food?, I noted that some of my students say that to eat healthy one should avoid “processed food”.  What they did not seem to understand is that most of the food we eat is processed to some extent.  Whole wheat bread is a healthy choice but bread is a “processed food”.  They harvest the grain, mill the grain, make the flour and then make the bread.  Cereal, canned vegetables, frozen vegetables, 100% juice – all are processed to some extent. 

But now there is “ultraprocessed food”.  These foods are not only highly processed but often contain a lot of added sugar, salt and fat as well as preservatives and many have artificial coloring added.  These foods are usually low in fiber and low in protein.  

What foods are considered ultraprocessed foods ?

• Frozen meals: premade meals
• Processed meats: Hot dogs, cold cuts like bologna, sausage, bacon, ham
• Fast food – chicken nuggets, French fries, etc.
• Packaged desserts like cookies and cakes
• Salty snacks like Cheetos
• Soft drinks

Who eats ultraprocessed foods?

Probably most of us eat some ultraprocessed food.  A study in BMJ of 9317 participants found that ultraprocessed foods accounted for a whopping 57.9% of the participant’s daily calories.  This added a lot of added sugar to their day as the amount of added sugar in processed foods is 8X the amount in processed foods.        

Are ultraprocessed foods linked to heart disease and cancer? 

A study from Tufts University found that eating a lot of ultra-processed food increased the risk of colorectal cancer in men.  A recent study of over 200,000 American adults found that “men who ate the most ultra-processed food had a 29% higher risk for colon cancer”.

For women, there is an increased risk from eating “ready-to-eat/heat mixed dishes”. 

Another study found that diets highest in ultraprocessed foods had an increased risk for heart disease.  

Are some foods protective?

One study found that yogurt and dairy desserts were protective for women and “appear to limit the colon cancer risk for women”.  Note that this is dairy foods made from cow’s milk.  Unclear if the plant-based milks are protective.

The American Cancer Society offers advice on how to reduce your risk of colon cancer.  These include getting screened, getting regular exercise, weight control, not smoking, avoiding alcohol and of course DIET.

What are the dietary recommendations to reduce one’s risk of colon cancer?  Eating lots of fruit, vegetables and whole grain foods are protective.   This is probably because these foods provide healthy antioxidants and fiber. Another recommendation is to eat less processed foods and definitely less ultraprocessed food.    GoodRX notes:

• Fiber is an important part of a healthy diet.
• Eating more fiber has been linked to a lower colon cancer risk.
• High-fiber foods include whole grains, vegetables, and fruit.

Interesting how different doctors deal with diet and colon cancer.  My gastroenterologist made no recommendations on diet or fiber intake when counseling me on colon cancer prevention.  In contrast, my husband’s gastroenterologist gave him a full-page list of the fiber content of various foods and advised him to increase his fiber intake.  The American Institute of Cancer Research “recommends that adults consume at least 30 grams of dietary fiber each day as part of a healthy eating pattern to lower cancer risk”.  For most people, that is a huge increase in fiber as most women consume only 15 grams of fiber a day and men consume about 18 grams of fiber a day.  For a list of fiber-rich foods go to The Top Fiber-Rich Foods List.  A note of caution.  Add fiber rich foods to your diet slowly or you will experience what my daughter calls “bubble gut”.  It takes your body awhile to adjust to adding more fiber to your diet.  So do this over a period of weeks, not days.

Some suggestions for reducing ultra processed foods.  The more minimally processed foods are often around the perimeter of the grocery store.  Thus, fresh fruit and vegetables, dairy products.  Enjoy an apple instead of applesauce.  Enjoy a baked potato instead of French fries.  Drink real 100% juice instead of SunnyD or a fruit punch drink.  Better yet, eat an orange.  Eating more meals at home or packing your lunch and snacks is another way to cut back on ultraprocessed foods in your diet.  Make healthier choices.  Instead of potato chips, choose SunChips or enjoy some popcorn.  I tell my students they don’t have to give up chips but to choose healthier chips.  Instead of potato chips, choose SunChips or enjoy some popcorn. 

Think about the foods you eat and how you may be able to cut back on some of the ultraprocessed foods and how you may add more fiber to your day.

Sources:  Should You Avoid Ultraprocessed Food? , foods , ultraprocessed foods , BMJ , heart disease and cancer , study , study , heart disease , American Cancer Society , GoodRX , American Institute of Cancer Research , The Top Fiber-Rich Foods List  Image Sources:   Processed foods ,  Less processed chart , Foods with fiber