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Rates of colon cancer in people under the age of 50 are rising. James Kinross, a GI surgeon who researches how the gut microbiome affects our risk of the disease, believes “an internal climate crisis” among people in Western countries could be partly to blame.
But “the gift of the gut microbiome is that you can change it,” said Kinross, referring to the trillions of microbes that populate our digestive system, and which research suggests have a wide-ranging affect on our health. “It is an ecosystem that you can adapt,” the researcher at Imperial College London told Business Insider.
To lower his own risk of developing colon cancer, the second deadliest form of cancer disease in the US, Kinross follows dietary principles including eating a vegetarian diet. However, as BI has previously reported, a person’s diet is just one piece of the puzzle when it comes to colon cancer risk.
Environmental factors such as ultra-processed foods, the use of antibiotics, which kill gut bacteria, microplastics, and limited exposure to nature, are thought to have made our gut microbiomes less diverse, he said. That means it’s less healthy and resilient.
He gave the example of a child who is born by C-section, which means missing out on microbes that would have been passed on via the birth canal, to a mom whose gut microbiome is depleted by antibiotics, and fed a diet of ultra-processed foods, he said.
“You’re seeing a generational loss in our internal ecology, which is being hammered with a series of environmental hits that it simply cannot adapt to,” Kinross said.
The consequence is “a very unhappy microbiome,” which produces harmful molecules and toxins that affect colon cancer risk, he said.
Kinross shared how he eats to lower his risk of colon cancer.
Eat 30 grams of fiber a day
“What I really want in my gut is diversity,” Kinross said, “and the way you get that is by having a really good diverse diet which is really high in fiber.”
Fiber is found in plant foods such as fruits, vegetables, nuts, seeds, legumes, and whole grains, and studies suggest that a diverse gut microbiome is linked to a range of health benefits, such as a strong immune system.
Kinross aims to eat 30 grams of dietary fiber a day, as recommended by the Food and Drug Administration. He tries to “eat the rainbow,” ensuring that his plate is filled with plant foods of lots of different color and, therefore, nutrients.
Follow a vegetarian diet
Research has found a strong link between eating processed and red meats and colon cancer risk, so Kinross tries to follow a vegetarian diet as much as possible.
One 2020 study published in the International Journal of Epidemiology looked at data from around 500,000 people over a seven-year period to assess whether eating meat affected their cancer risk. It found that those who ate 79 grams of red or processed meat, or the equivalent of three slices of deli meat per day on average, had a 32% higher risk of colon cancer compared to those who ate less than 11 grams.
In 2015, The International Agency for Research on Cancer, the cancer research agency of the World Health Organization, classified processed meat as a “definite” cause of cancer, and red meat as a “probable” cause.
“I don’t necessarily believe that we all have to be vegetarian, but I think meat consumption is a big part of our problem,” he said, referring to rising colon cancer cases.
Eat fermented foods daily
Fermented foods, such as sauerkraut, kefir, and kombucha, contain probiotics, the “good” bacteria that live in the gut.
Kinross eats a serving of them daily, as research suggests they can improve the diversity of the gut microbiome. A 2021 study by Stanford University found that people who ate a diet high in fermented foods for 10 weeks had even more diverse microbiomes than those who ate a high-fiber diet.
His go-to’s are sourdough bread and kimchi, a Korean fermented cabbage dish.
“My daughter’s completely obsessed by kimchi. She makes loads of it. So we’ve always got a big bucket of it in our house,” he said.
“They’ve got to be part of your regular food consumption, otherwise, the microbes just don’t culture and graft into your gut,” he said.
