For an overview of cancer as a metabolic disease, start here.

Cancer cells thrive on certain fuels–including glucose and glutamine, two key elements that you must inhibit in your anti-cancer diet. We’ve talked ad nauseum about glucose. But what about glutamine, an amino acid, a building block of protein? 

Glutamine is ubiquitous. It’s everywhere–even in many plant sources of protein. It gives that umami flavor to mushrooms, soy sauce, seaweeds, ripe tomatoes.  And even if you don’t get glutamine from your diet, your body will make the amino acid if and when it senses you’re deprived. That’s probably because cells, especially immune cells, need some glutamine to do their jobs. 

But if you have cancer, glutamine can spur tumor growth. 

While you’ll never be able to eliminate glutamine from your diet, you can, however, eat foods that keep cancer cells from using glutamine. Here’s the what, why and how:  

• green tea: contains EGCG, which inhibits an enzyme, glutamate dehydrogenase, that helps cancer cells use glutamine
• ashwaghanda: contains the enzyme L-asparaginase, which keeps you from digesting glutamine. Make a relaxing tea from it.
• seeds of fresh peppers: All peppers from the capsicum annum family, including the large sweet bells and many smaller pungent peppers, contain L-asparaginase, especially in their seeds.  (If you don’t have cancer, however, avoid a steady diet of pepper seeds due to your body’s need for glutamine.)

And while we’re on the subject of Thomas Seyfried, one of the most important minds in cancer cell metabolism (how cancer cells use fuels for growth), he also recommends fasting, such as long overnight fasts, to get your body into ketosis, a state in which it burns fats not glucose. Once you’re there, he suggests adding hyperbaric oxygen treatments to help kill cancer cells. Read my Love Letter to Senator McCain for an overview of Seyfried’s anti-cancer approach. 

photo of anti-cancer peppers courtesy of Montreal artist Peggy Ann Turner