Keto and cancer: What do we really know?

It wasn’t all that surprising to read this headline yesterday on a celebrity news site: Keto Diet May Give Alex Trebek 1 Potent Weapon to Fight Deadly Cancer. Speculation on keto’s potential to fight cancer is (like CBD’s) rampant, but, as of now, it’s mainly that: speculation. Still, it’s extremely encouraging speculation. A growing amount of research from Cornell University and other institutions supports the theory that sugar accelerates the growth of many types of cancer, and implies that a ketogenic low-carb diet could starve tumor cells. A study published last year in Nature showed that a keto diet in combination with certain cancer drugs worked on experimental mouse and human cancers. Research into whether the keto diet reduces tumor growth in endometrial cancer patients is now getting underway.

The idea that restricting sugar consumption can effectively “starve” tumors dates back to the 1920s, when Nobel Prize-winning physiologist Otto Warburg discovered that tumor cells, unlike normal cells, metabolize glucose in a way that sustains their fast growth. Yet research into the sugar connection mostly went cold as cancer scientists turned their attention to the role of genetics. In recent years, more scientists are coming around to Warburg’s ideas — at least considering it, if not fully embracing it. (Interestingly, though, cancer diagnosis has long been informed by PET scans that identify cells — tumors — with unusually high glucose consumption.) 

There are some promising findings so far, including indications that a calorie-restricted keto diet could improve the prognosis for aggressive brain cancers. At least 10 clinical trials are currently exploring keto’s role in treatment for glioblastoma, and dozens of others are looking at keto’s potential in helping treat other types of cancer. 

While some research has focused on keto as a non-toxic alternative to conventional cancer therapies (fasting falls into this category, too), more are looking at the potential of keto in combination with cancer drugs. In fact, what prompted the Nature study was the discovery that a drug designed to inhibit an enzyme implicated in tumor growth seemed to trigger diabetes in patients. As The New York Times explains, the drug seemed to be providing a “starvationlike” signal not only to the tumor cells, but also, to the liver, which responded by flooding the blood with glucose in response (which seemed to cancel out the drug's benefits). As research progresses, we’ll understand more about the role the keto diet can play in cancer treatment. But, even now, there seems to be good reason for optimism.