You discussed glutamine supplementation in the gut section. This information from Memorial Sloan Kettering Cancer Center indicates that glutamine may fuel cancer cell growth. Do you have any suggestions on weighing the risk versus benefit?

Chris Kresser:  And this is a quote from the study. “Recent findings show that glutamine transporters upregulated tumor cells and that glutamine acts as a mitochondrial substrate and promotes protein translation. This indicates tumor cell dependence for growth and maintenance, and a recent study demonstrated that glutamine helps cancer cells survive acidic stress rather than provide nutrition through enzymatic deamidation.” Yeah, this is an interesting finding and a key, another reason why I generally like to use supplements for as short of a time as possible to achieve a particular therapeutic goal and then get back to diet and lifestyle. The thing with cancer is difficult because all of the things that fuel normal cell processes and make us feel good can also fuel cancer cells. So you could say that a high-protein diet could fuel cancer growth and that’s true, which is one of the reasons why it’s difficult to make solid dietary recommendations in a patient who has cancer. That doesn’t mean other people shouldn’t be eating a higher-protein diet. It’s the same thing here. Some patients with GI issues or not, you don’t have cancer and aren’t at risk for cancer glutamines probably could be helpful in those situations. But in someone who already has cancer, it’s not hard to understand how glutamine could help especially if the cancer is in the gut or could hurt especially if the cancer’s in the gut.