“Direct link” found between eating fiber and anticancer effects

Read the wheat too!

We know that fiber is essential to a healthy and nutritious diet, yet only 7% of Americans eat the recommended daily amount. A new study from Stanford Medicine highlights the importance of dietary fiber, as it may reduce the risk of cancer by altering gene activity.

When we consume fiber, bacteria in our gut break it down into small molecules called short-chain fatty acids. The Stanford researchers examined two of these byproducts—propionate and butyrate.

They found that these compounds can modify histones, proteins that help package DNA, making DNA more accessible and influencing gene expression.

This means that in certain situations, propionate and butyrate can suppress cancer-promoting genes and activate tumor suppressor genes.

“We found a direct link between eating fiber and modulating gene function that has anti-cancer effects,” explained Stanford genetics professor Michael Snyder. “We think this is likely a global mechanism because short-chain fatty acids resulting from fiber digestion can travel throughout the body.”

Snyder’s team tracked the effects of propionate and butyrate on healthy and cancerous colon cells and cells in the intestines of mice fed fibrous diets.

Both fatty acids have been shown to suppress cell growth, encourage cell specialization, and induce programmed cell death, particularly in cancer cells. These processes are important for stopping or controlling the uncontrolled cell growth that is the hallmark of cancer.

“By identifying the gene targets of these important molecules, we can understand how fiber exerts its beneficial effects and what goes wrong during cancer,” Snyder said.

His findings were published last week in the journal Nature Metabolism.

Considering the rise in colorectal cancer, especially among young adults, Snyder suggests optimizing fiber diets to improve health and reduce cancer risk.

Fiber is known to promote regular bowel movements, help stabilize blood sugar levels, lower cholesterol and contribute to overall heart health.

The American Heart Association recommends getting at least 25 to 30 grams of fiber a day from food — although most Americans only consume about 15 grams a day.

“It’s generally the case that people’s diets are very low in fiber, and that means their microbiome isn’t getting enough nutrition and can’t produce as many short-chain fatty acids as they should,” Snyder said. “This is not good for our health.”

How to include fiber in your diet

Stephanie Schiff, a registered dietitian at Northwell Huntington Hospital, shared five top ways to get more fiber in your diet.

• Whole grains – oats, barley and bulgur wheat
• Beans, peas and legumes – black beans, kidney beans, lentils and split peas
• Fruits – avocados, raspberries, blackberries, pears and apples
• Vegetables – broccoli, asparagus, artichokes and Brussels sprouts
• Nuts and seeds – chia seeds, flax seeds, pumpkin seeds and almonds