Cancer experts are desperate to find an explanation for the dire trend of rising cancer rates among young people.
A study published in JAMA Network Open last year found that cancer diagnosis rates among people in their 30s rose about 20% between 2010 and 2019, with most of that increase occurring among women.
Digestive tract cancers (including intestinal, colon, colorectal, appendix, bile duct, and pancreatic cancer) showed a staggering 15% increase during the study period, making them the cancer type with the highest growth rate.
Additionally, according to the American Cancer Society, 20% of new colorectal cancer diagnoses in 2019 were in people under the age of 55, up from 11% in 1995.
Some experts and studies suggest that the rise in colorectal cancer diagnoses is due in part to a Western diet that favors ultra-processed foods (UPF) and is low in fiber.
Research suggests that a high fiber intake may reduce the risk of several types of cancer, including esophageal, stomach, colon, and rectal cancer.
But what about young, healthy people who already follow healthy eating habits?
Speaking to the Daily Mail this week, British cancer specialist Carol Sikora acknowledged that junk food and UPF could be factors, but:It is far too simplistic to say that these are the sole causes of rising cancer incidence.
Sikora said the real reasons remain unknown and are likely multifaceted. “It doesn’t seem to be specifically related to obesity, and there’s no difference in the increased rates of early cancer in vegetarians, so that’s part of the mystery.”
Sikora thinks that changes in the younger generation’s gut bacteria and other microorganisms that live there may be to blame.
“A healthy microbiome is crucial for bowel cancer prevention, as intestinal cells are bathed in products made by bacteria 24/7,” he explained to the Daily Mail, “so it’s not surprising that any changes could raise or lower your chances of developing bowel cancer.”
But as Sikora points out, that correlation is difficult to establish: “The problem with analyzing it is that there are so many factors that affect the microbiome: diet, alcohol, how food is prepared, etc.”
London-based oncologist Hendrik Tobias Arkenau said the most worrying consequence of the rise in cancer among younger people was that many patients were being diagnosed at a later or terminal stage of the disease.
He asks: “Why would anyone assume that a 35- or 42-year-old has colon cancer just because they have abdominal pain, weight loss and blood in their stool?”
While Arkenau supports the microbiome theory, other contributing factors include childhood antibiotic use, changes in diet, vitamin intake and rates of breastfeeding failure.
“There’s no one clear cut answer,” he told the Daily Mail. “I think there are multiple factors at play and there are other aspects, such as low vitamin D levels.”
Approximately 35% of U.S. adults have vitamin D deficiency, and some studies suggest an association between low vitamin D levels and an increased risk of some cancers.
Arkenau said there’s no definitive answer as to why cancer is occurring at such a high rate among young people, but he argues health care professionals can keep an eye out for worrying symptoms.
“If someone comes in and says, ‘I’ve lost weight, I’ve had a little bleeding, I’ve got a little stomach pain,’ that doesn’t necessarily mean it’s irritable bowel syndrome, so it’s not necessarily appropriate to say, ‘Come back in three months and get checked,'” he said.
