Colon cancer rates are rising in the United States among people 50 and younger, with a 15% increase in diagnoses since 2004. Dr. Minia Hellan, a surgical oncologist, explains that family history increases your risk, but most cases are due to lifestyle factors such as obesity, alcohol use, and low physical activity. 

But perhaps the most significant factor in increased colon cancer rates is what Dr. Hellan refers to as the “westernization” of our diet. 

“It’s the consumption of mostly refined grains and heavily processed food, which has a lot of saturated fat. Also, a low intake of dietary fiber.” 

And, according to Dr. Hellan, recent studies suggest that eating enough dietary fiber may reduce your risk for colon cancer. 

Fiber and colon cancer 

Dr. Hellan shares that there is some evidence that increased fiber intake is beneficial to colon health. 

“There seems to be good evidence that you do get a risk reduction of developing polyps and colon cancer if you increase your dietary fiber.” 

In fact, there is evidence that the two types of fiber—soluble and insoluble—play different roles in this risk reduction. 

According to Dr. Hellan, soluble fiber helps the microbiome, the natural bacteria found in the colon, flourish. But eating a highly processed diet can harm the microbiome and cause an overgrowth of bad bacteria in the colon. 

Insoluble fiber plays a more physical role in reducing the risk of colon cancer. Dr. Hellan notes that these fibers bulk up stool and prevent constipation. 

“The idea is that the toxic substances don’t stay as long in the colon because your bowels are moving better,” she says. “So that could be one of the reasons why it can help reduce the carcinogens in the colon.” 

The recommendation is 30 grams of fiber a day, and where it comes from matters. Instead of reaching for fiber tablets or powder, Dr. Hellan stresses the importance of getting your daily recommended fiber through your food to reap the benefits. 

“You cannot replace a bad diet by just taking supplements and multivitamins.” 

The Mediterranean diet 

In the U.S., we often reach for packaged foods for snacks at work and stock our pantries and freezers with processed food. And while these foods can certainly be more convenient and cost-effective, Dr. Hellan says this diet contributes to the increased risk of cancer. Instead, she tells her patients to follow a Mediterranean-style diet. 

“The recommendation,” she says, “is that our food should be mostly plant-based with a lot of fruits and vegetables.” 

This diet emphasizes eating whole, unprocessed foods such as

• Fruits 
• Vegetables 
• Whole grains like quinoa and brown rice 
• Beans and other legumes 

The diet also recommends white meat such as chicken, turkey, and fish, with little to no red meat such as beef and pork. It also includes plant-based oils and fats like olive oil instead of butter. 

With less saturated fats, sugar, and processed food, this diet has been shown to reduce the risk for cardiovascular disease and type 2 diabetes, as well as other cancers. It also naturally increases your dietary fiber intake, which could play a big part in reducing the risk of colon cancer. 

Overall, eating a whole, plant-based diet like the Mediterranean diet may not only reduce your risk of colon cancer, but also other cancers and other life-threatening conditions.