Colorectal cancer is now one of the fastest-growing types, a US-based gastroenterologist said, noting that the early-onset cancers, under age 50, have risen nearly 80% worldwide over the past 30 years.
In a viral Instagram post, Dr Saurabh Sethi, a Harvard-certified Gastroenterologist, shared one common pattern in all the cases of early-onset colorectal cancers — Ultra-processed foods.
“A large JAMA Oncology study linked higher intake of ultra-processed foods with increased colorectal cancer risk markers,” he said.
Dr Sethi also said that women consuming the highest amounts of ultra-processed food, about 1/3of daily calories, had 45% higher risk of precancerous colon polyps. “Polyps are often the earliest step toward colon cancer.”
“Ultra-processed diets are associated with chronic low-grade inflammation, microbiome disruption, and metabolic dysfunction,” he said.
“All factors linked to colorectal cancer development,” the gastroenterologist shared, saying that the goal isn’t perfection – “It’s lowering daily exposure.”
What is colorectal cancer?
Colorectal cancer is a type of cancer that starts in the colon, the longest part of the large intestine, or the rectum, the last several inches of the digestive tract. Because they share many features, they are grouped under one name.
Most of these cancers begin as small, non-cancerous growths called polyps. Over several years, some of these polyps can turn into cancer.
The cancer usually begins in the mucosa, which is the innermost lining of the colon or rectal wall. If left untreated, it can grow outward through the layers of the wall and eventually spread to lymph nodes or other organs.
Key risk factors of colorectal cancer
While anyone can develop colorectal cancer, certain factors increase the likelihood:
- Advancing age significantly increases the risk of cancer; however, early-onset cases are rising.
- Family history: Having a close relative with the disease.
- Health history: Conditions like Type 2 diabetes or inflammatory bowel diseases (like Ulcerative Colitis or Crohn’s).
- Lifestyle: Diets high in processed meats, sedentary lifestyle, smoking, and heavy alcohol use.
5 practical ways to reduce risk:
- Reduce ultra-processed ‘staples’
Dr Sethi said that the major contributors to cancer are ultra-processed items like packaged breads, sweetened yogurts, cereals, flavoured creamers, and bottled sauces.
“Small swaps add up,” he noted.
- Prioritise fibre
Dr Sethi highlighted the need for proper fibre intake and said that one must “aim for 25-38 grams daily”.
“Fibre feeds beneficial gut bacteria and supports colon health,” he said. - Minimise sugary drinks
The gastroenterologist said that the liquid sugars are linked to metabolic stress and gut inflammation.
He said that water, coffee, and unsweetened tea are better defaults. - Choose shorter ingredient lists
“Food should look like food,” Dr Sethi suggested.
The gastroenterologist said if the label reads like a chemistry experiment, “it’s likely ultra-processed”. - Know the warning signs
Dr Sethi said people should keep an eye on warning signs such as persistent changes in bowel habits, blood in stool, unexplained weight loss, ongoing abdominal pain, and unusual fatigue.
“Persistent symptoms deserve evaluation,” he said.
Early detection is key
Colorectal cancer is one of the most preventable types of cancer because it starts as a polyp. It can actually be found and removed during a colonoscopy before they ever have the chance to turn into cancer.
