The nut that’s a colon cancer-fighting trifecta

You may have read that nuts are like disease kryptonite. That’s not an exaggeration.

Lots of studies have shown that nuts help prevent diseases like cancer, diabetes and cardiovascular disease. They have even helped reduce cancer recurrence in both breast and colon cancer survivors.

So it’s no wonder that researchers continue to return to nuts for answers…

Colorectal cancer is the second deadliest form of cancer (after lung cancer). It kills about 50,000 Americans a year, and in the last several years, it has begun to strike younger people.

One nut in particular stands out against colon cancer — and now researchers know why it’s so special — and why it should be part of your cancer prevention arsenal…

Eating walnuts produces anti-cancer molecules

“Our study provides strong rationale for dietary inclusion of walnut ellagitannins for cancer prevention”, says Dr. Daniel Rosenberg of the UConn School of Medicine.

Ellagitannins are plant-derived polyphenol compounds found in walnuts that are metabolized by the gut into a variety of molecules known as urolithins.

And according to Dr. Rosenberg, “Ellagitannins in the walnut are importantly providing the anti-inflammatory and anti-cancer properties that we’re seeing in patients in our clinical trial research, particularly the gut’s conversion of ellagitannins to a potent anti-inflammatory agent, urolithin A.”

In that research, patients between the ages of 40 and 65 years, who were referred to the clinical trial because of an elevated risk for colon cancer, abstained from foods with ellagitannins for a week. Then, they began eating walnuts as part of a controlled diet.

After three weeks, all patients underwent a high-definition colonoscopy.

Higher levels of urolithin A in urine correlated with higher levels of peptide YY, a protein thought to help inhibit colon cancer.

At the same time, Dr. Rosenberg and his team obtained a direct view of cellular interactions within colon polyps removed during the colonoscopy.

After three weeks of eating walnuts, they observed that patients with higher levels of urolithin A also had reduced levels of the protein vimentin, which is often associated with more advanced forms of colon cancer.

“Urolithin A has a very positive influence on inflammation and maybe even cancer prevention,” says Dr. Rosenberg.

“Our study proves that dietary supplementation with walnuts can boost the general population’s urolithin levels … while significantly reducing several inflammatory markers, especially in obese patients.”

Walnuts: a trifecta against colon cancer

So let’s review the findings that make eating walnuts a no-brainer to avoid colon cancer…

• Ellagitannins from eating walnuts are converted to urolithin A by the gut.
• Higher levels of urolithin A correlated with higher levels of the cancer-inhibiting YY protein and lower levels of vimentin, a protein linked to advanced cancer.
• Inflammatory markers are significantly reduced. Previous research has shown that inflammation is linked to tumor growth.

Three reasons to believe Dr. Rosenberg when he says, “Nutrients from walnuts can contribute to reduced cancer risk. There are many potential benefits one can get from eating walnuts, with so little downside risk, that just grabbing a handful every day is really something that you can easily do for your long-term health benefit.”

According to the Colon Cancer Foundation, as many as 75% of cases of colorectal cancer are preventable through healthy eating.

Food to eat for a healthy colon includes:

• Fiber-rich fruits and vegetables. Eat whole fruits with the skin on and include vegetables like broccoli, leafy greens (spinach, kale) and berries. 
• Whole grains. Choose whole grains like oats, brown rice, and quinoa over refined grains. 
• Lean protein. Choose lean sources like fish (especially fatty fish like salmon for omega-3s), chicken, eggs, beans and nuts. 
• Calcium and Vitamin D. Consume low-fat dairy, fortified milk, eggs and leafy greens. 
• Probiotic-rich foods. Incorporate yogurt (with live cultures), kefir, sauerkraut, kimchi and miso to support gut health. 
• Healthy fats. Include nuts and olive oil for omega-3 fatty acids. 

Foods to limit or avoid:

• Processed and red meats. Minimize or eliminate hot dogs, deli meats and bacon.
• Fried foods. High-carbohydrate foods prepared at elevated temperatures may contain a cancer-causing chemical called acrylamide.
• Alcohol. Avoid altogether, if at all possible, or only drink on occasion. Alcohol is linked to 7 types of cancer, including colon cancer.
• Refined grains and processed foods. These are lower in fiber. Choose whole foods over their processed counterparts.

Sources:

Scientists Reveal That Eating Walnuts Could Reduce Your Risk of Cancer — SciTech Daily

Systemic Inflammation and the Inflammatory Context of the Colonic Microenvironment Are Improved by Urolithin A — Cancer Prevention Research

Eating for a Healthy Colon — Rush University