Addressing early-onset colorectal cancer in pediatric practice: Prevention starts now

Colorectal cancer was once considered a disease of aging, but not anymore. Although screening has driven down rates in adults older than 50 years, the opposite is true for younger populations. By 2030, early-onset colorectal cancer (EOCRC) could account for up to 11% of colon cancers and 24% of rectal cancers, with rates in 20- to 34-year-olds expected to surge by more than 90%.¹ These cancers often present at more advanced stages, with a higher risk of metastasis and poorer outcomes.

Although some cases are tied to hereditary syndromes or family history, most are not. This raises the question: Could childhood dietary choices play a role? Pediatricians don’t screen for colon cancer, but we are often the first—and sometimes only—touchpoint in shaping a child’s long-term eating habits. In this article, we’ll examine the dietary risk factors driving this alarming trend, explore how fiber and other protective foods can reduce cancer risk, and provide practical strategies for assessing and improving your patients’ long-term colon health.

Understanding the rise of EOCRC

Rising rates of pediatric obesity, poor diet quality, and sedentary lifestyles may be fueling the surge in EOCRC. Excess weight in adolescence is linked to long-term inflammation, insulin resistance, and microbiome disruption, all of which contribute to carcinogenesis.² The traditional Western diet, which is rich in red meat, sugar, and ultraprocessed, high-fat foods, compounds these risks. One study found that high-fat diets nearly doubled the risk of EOCRC, and frequent fast-food consumption was tied to a 10-fold increase in risk.¹

Particularly concerning is high consumption of sugary drinks during adolescence, especially when paired with low fruit intake. One longitudinal study showed that high school students with the highest intake of sugary drinks had a greater risk of developing colorectal adenomas before 50 years of age, especially when fruit intake was low.³

The fiber gap: A critical intervention point

Fiber is one of the most powerful tools to support long-term colon health, yet it remains drastically underconsumed. A 2017 analysis found that 95% of Americans, including children, fall short on fiber, recognizing it as a “nutrient of concern” in the Dietary Guidelines for Americans.^4,5 Young children in the United States average only 7 to 9 g of fiber per day for toddlers and 10 to 11.5 g for preschoolers, which is far below the recommended levels.⁶

Current fiber recommendations by age: The Institute of Medicine’s Dietary Reference Intake for dietary fiber is 14 g fiber/1000 kcal⁷:

• Ages 1 to 3 years: 19 g
• Ages 4 to 8 years: 25 g
• Ages 9 to 13 years: 26 g (girls), 31 g (boys)
• Ages 14 to 18 years: 26 g (girls), 38 g (boys)

A quick clinical shortcut: “Age + 5” provides a reasonable estimate of a child’s daily fiber needs.

How fiber protects against colorectal cancer

Fiber classification can get complicated, but for practical purposes, focus on 2 main types: soluble and insoluble. Soluble fiber (eg, oats, beans, apples, and many vegetables) dissolves in water and forms a gel-like substance in the gut. It’s easily fermented by gut bacteria and produces short-chain fatty acids, such as butyrate, which strengthens the gut lining, reduces inflammation, and helps regulate immune function.⁸ Insoluble fiber (eg, whole grains, fibrous vegetables) adds bulk and promotes regularity.⁸

Together, they promote gut motility, relieve constipation, feed beneficial bacteria, support blood sugar regulation, shorten gut transit time, and modulate inflammation.^8-10 One large prospective study found that participants who ate the most whole grains had a 16% lower risk of colorectal cancer.²

Beyond restriction: Protective foods to recommend

Although much of the conversation focuses on what to limit, it’s equally important to highlight what to increase. High intake of whole fruits, vegetables, legumes, whole grains, and nuts/seeds has been associated with lower cancer risk.³ These foods are rich in anti-inflammatory and antioxidant compounds, such as b-carotene, vitamin C, vitamin E, and folate, which help regulate cell turnover and may slow cancer progression.

Practical strategies

Translating fiber recommendations into real food can feel daunting for families. Here are 5 fiber-rich foods that are typically well accepted by children:

1. Popcorn (2 g per 3 cups, popped): Perfect for movie night and counts as a whole grain
2. Raspberries (4 g per ½ cup): Blueberries and strawberries come in lower, at approximately 2 g per serving, but are still great choices
3. Pears (5.5 g): Juicy and sweet—bonus points for eating the skin
4. Green peas (4 g per ½ cup): Add to pasta or rice dishes
5. Spinach (4 g per 1 cup cooked): Blend into smoothies or sauces

The pediatrician’s role in cancer prevention starts now

The rise in EOCRC isn’t happening in isolation; it reflects broader trends such as rising pediatric obesity, ultraprocessed diets, sugary beverage intake, and sedentary lifestyles. Because risk accumulates long before screening age, pediatricians have a unique window to intervene early. Here are a few practical questions you can weave into routine visits:

1. “Tell me about a typical day of eating for [child’s name].”
2. “What fruits and vegetables do you like?”
3. “Do you poop every day? What do they look like?”
4. “What kind of drinks do you like?”

When you identify areas for improvement, focus on small, achievable changes, such as swapping 1 sugary drink for water daily, adding berries to cereal, and choosing nuts instead of chips. These conversations plant seeds that can grow into lifelong habits.

The prevention of EOCRC shouldn’t start in the gastroenterology office at age 45. It starts with us, in the pediatric office, addressing obesity, improving diet quality, and increasing fiber intake, 1 conversation at a time.

References:

1. Spaander MCW, Zauber AG, Syngal S, et al. Young-onset colorectal cancer. Nat Rev Dis Primers. 2023;9(1):21. doi:10.1038/s41572-023-00432-7
2. Rock CL, Thomson CA, Sullivan KR, et al. American Cancer Society nutrition and physical activity guideline for cancer survivors. CA Cancer J Clin. 2022;72(3):230-262. doi:10.3322/caac.21719
3. Carroll KL, Frugé AD, Heslin MJ, Lipke EA, Greene MW. Diet as a risk factor for early-onset colorectal adenoma and carcinoma: a systematic review. Front Nutr. 2022;9:896330. doi:10.3389/fnut.2022.896330
4. Quagliani D, Felt-Gunderson P. Closing America’s fiber intake gap: communication strategies from a food and fiber summit. Am J Lifestyle Med. 2016;11(1):80-85. doi:10.1177/1559827615588079
5. Dietary Guidelines for Americans, 2020-2025 and online materials. Dietary Guidelines for Americans. Accessed July 31, 2025. https://www.dietaryguidelines.gov/resources/2020-2025-dietary-guidelines-online-materials
6. Finn K, Jacquier E, Kineman B, Storm H, Carvalho R. Nutrient intakes and sources of fiber among children with low and high dietary fiber intake: the 2016 feeding infants and toddlers study (FITS), a cross-sectional survey. BMC Pediatr. 2019;19(1):446. doi:10.1186/s12887-019-1822-y
7. Trumbo P, Schlicker S, Yates AA, Poos M; Food and Nutrition Board of the Institute of Medicine, The National Academies. Dietary reference intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein and amino acids. J Am Diet Assoc. 2002;102(11):1621-1630. doi:10.1016/s0002-8223(02)90346-9
8. Celiberto F, Aloisio A, Girardi B, et al. Fibres and colorectal cancer: clinical and molecular evidence. Int J Mol Sci. 2023;24(17):13501. doi:10.3390/ijms241713501
9. Schwingshackl L, Schwedhelm C, Hoffmann G, et al. Food groups and risk of colorectal cancer. Int J Cancer. 2018;142(9):1748-1758. doi:10.1002/ijc.31198
10. Vernia F, Longo S, Stefanelli G, Viscido A, Latella G. Dietary factors modulating colorectal carcinogenesis. Nutrients. 2021;13(1):143. doi:10.3390/nu13010143