Ultra-Processed Foods May Raise Risk In Women

• A new study reports that there is an association between ultra-processed foods and the risk of developing polyps that could progress into colorectal cancer in women under the age of 50.
• Experts say these findings back up previous research on unhealthy diets and colorectal cancer, but they said the risks also apply to men.
• They recommend a balanced diet of nutrient-rich foods that includes whole grains and fruits and vegetables of various colors.

A new study found an association between ultra-processed foods and the risk of polyps that may grow into colorectal cancer — or “colorectal cancer precursors” — in women under the age of 50.

Female participants who had the highest intake of ultra-processed foods had a 45% higher risk of developing precancerous colon polyps than participants with a lower intake of ultra-processed foods.

“These data highlight the important role of [ultra-processed foods] in early-onset colorectal tumorigenesis and support improving dietary quality as a strategy to mitigate the increasing burden of [early onset colorectal cancer],” the study authors wrote.

Experts not involved in the study told Healthline that the findings back up previous research on colorectal cancer risk in younger adults.

“There is a global epidemic with rising incidence of colorectal cancer in younger adults,” said Katherine Van Loon, MD, a specialist in gastrointestinal cancer at the University of California San Francisco. “Up to this point, there has not been a clear explanation for the rising numbers, although we have a growing body of literature that diet, obesity, and other environmental exposures may contribute to the increased risks.”

“This study elucidates another potential contributing risk factor for the development of precancerous lesions in young woman,” Van Loon noted.

“This study is in line with previous data showing a link between early onset of [colorectal cancer] and the lifestyle connections associated with this risk,” added Kristin Kirkpatrick, RD, the president of KAK Consulting and a dietitian at the Cleveland Clinic Department of Wellness & Preventive Medicine in Ohio. “This is also consistent with previous data showing the general adverse impact of a high consumption of [ultra-processed foods].”

“Overall, this study adds to the growing evidence that high consumption of ultra-processed foods may play a role in early colorectal cancer development,” said Caroline Um, PhD, MPH, a principal scientist in epidemiology research at the American Cancer Society.

“Although further research is needed to confirm these findings and understand underlying mechanisms, limiting ultra-processed foods and emphasizing whole, nutrient-rich options align with current cancer prevention guidelines,” Um said.

However, Tracey Childs, MD, a specialist in general and colorectal surgery and chief of surgery at Providence Saint John’s Health Center and an adjunct associate professor of surgery at Saint John’s Cancer Institute in California, noted these findings should be expanded to include males.

“One cannot make the assessment that women are higher risk than men in developing colorectal cancer from ultra-processed foods as this study was only done in women and did not look at men at all,” Childs said.

For the current study, the researchers analyzed the medical records of more than 29,000 female nurses under the age of 50 who had participated in the Nurses Health Study II.

The study participants provided baseline data in 1991. They had follow-up check-ins between June 1991 and June 2015. The median follow-up period was 13 years.

The nurses reported on their food intake the previous 12 months via questionnaires they received every 4 years.

The nurses in the study had an average age of 45 during the 24-year follow-up period. They had undergone at least one lower endoscopy before age 50 years after baseline and had no history of cancer — except for nonmelanoma skin cancer — before their endoscopy.

The researchers examined the data thus gathered between October 2024 and July 2025.

For this study, ultra-processed food intake was primarily from processed breads, breakfast foods, sauces, spreads, condiments, and sugar-sweetened or artificially sweetened beverages.

The researchers reported there were 1,189 study participants who were documented as having early-onset conventional adenomas and another 1,598 who had serrated lesions during the follow-up check-ins.

Noncancerous colorectal adenomas are growths or polyps in the colon and rectum that can lead to cancer. Serrated lesions are a type of precancerous polyp in the colon that are characterized by a serrated architecture and can be a pathway to the development of cancer.

In their study, the researchers reported that participants with the highest intake of ultra-processed foods, which was described as about 10 servings per day, had a 45% higher risk of developing adenomas by age 50 when compared with those with the lowest consumption, which was classified as about three servings per day.

There was no association observed between ultra-processed foods and serrated lesions.

Experts noted some limitations to this particular research besides the fact it only involved women. They pointed out that the information was gathered by questionnaire and that the definition of “ultra-processed” was somewhat general in nature.

Um said that alcohol was included as an ultra-processed food in this study.

“Because alcohol independently raises cancer risk, it would be helpful for future studies to examine ultra-processed food intake with and without alcohol,” she noted.

The Centers for Disease Control and Prevention (CDC) report there were nearly 150,000 cases of colorectal cancer in the United States in 2022, the latest year for which statistics are available.

The agency adds that more than 50,000 people died from the disease in 2023. Men had a higher incidence and death rate than women from colorectal cancer.

The American Cancer Society reports that the incidence of colorectal cancer has been declining in people 65 years and older. The incidence rate has remained stable for people ages 50 to 64.

However, the organization notes that colorectal cancer cases have been rising about 2% per year for U.S. adults ages 50 to 54 as well as those under the age of 50.

Previous research has concluded the obesity and diabetes are high risk factors for colorectal cancer in younger adults.

In addition, an April 2025 study reported that ultra-processed foods were linked to more than 120,000 preventable deaths per year in the United States.

The organization Food Tank estimates that 73% of the food supply in the United States consists of ultra-processed foods.

In addition, a 2022 study reported that almost 60% of the caloric intake of U.S. adults is ultra-processed foods.

Ultra-processed foods are described as mass-produced foods with a high level of industrially processed ingredients that are designed to ensure longer shelf lives.

Examples include commercially produced breads, most breakfast cereals, flavored yogurts, hot dogs, frozen meals, potato chips, soft drinks, and candy bars.

The study authors said that “ultra-processed foods are typically low in bioactive compounds, such as dietary fiber, vitamins, and polyphenols, and high in unhealthy fats, refined starches, and food additives such as emulsifiers and artificial sweeteners.”

They said these ingredients “could disrupt gut microbiota, increase intestinal inflammation, and contribute to colorectal carcinogenesis.”

Experts agreed. “The concept is that ultra-processed foods change the intestinal microbiome as well as enhance a pro-inflammatory environment, increasing the risk of pre-cancerous changes, which then can lead to early onset colon cancer,” said Childs.

“It’s also important to note that many ultra-processed foods contain a wide variety of additives, and we do not fully understand their effects on long-term health,” said Um.

Van Loon added that ultra-processed foods can lead to weight gain, which can also raise the risk of colorectal cancer.

“There is evidence from other research that ultra-processed foods promote excess energy intake, which can result in rapid weight gain,” she said.

A healthy, balanced diet is a key factor in reducing the risk of colorectal cancer.

The American Cancer Society (ACS) provides dietary recommendations for all adults to reduce their cancer risk. These include consuming:

• nutrient-rich foods that help you maintain a healthy body weight
• a variety of vegetables and fruits in different colors
• whole grains.

The ACS also recommends the avoidance of:

• red and processed meats
• sugar-sweetened beverages
• highly processed foods and refined grain products
• alcohol.

Beyond diet, ACS recommends:

• maintaining a healthy body weight throughout life
• being physically active
• reducing sedentary time.

Other experts are in agreement with these guidelines.

“I recommend a diet that is low in processed meats, low in red meat, low in processed grains, and low in sugar,” said Van Loon. “Choose whole grain breads and brown rice, and try to consume sugars from healthy sources such as fruits and vegetables.”

Kirkpatrick recommended a goal of eating healthy foods 90% of the time and indulging in less healthy foods 10% of the time.

“It’s not the frozen pizza that we may have once a month that does great harm. It’s when the frozen pizza becomes dinner three times a week. The greater the frequency of consumption of [ultra-processed foods], the greater the risk,” she said.