To fast or to … die sooner?

Intermittent fasting has been a buzz word of late. Does consuming fewer calories lead to a longer life? Does fasting starve cancer cells and improve cancer outcomes? Is intermittent fasting just another fad?

I’ve been interested in fasting more for it’s potential influence on cancer and the response to treatment.

My personal experience with intermittent fasting goes back to high school. Back then I didn’t call it fasting. I was a varsity wrestler, and when wrestling season started, so did all the customary rituals. I stopped eating, and I started spitting. I worked out in sauna suits and chewed gum to increase the amount of saliva I spat. Classmates didn’t like being around light-weight wrestlers because a pool of saliva accumulated around us wherever we sat. With a natural weight of 115 lbs, I weighed 98 lbs. I didn’t eat or drink anything for a week at a time. After weighing in for a meet, I would consume (rather, inhale) the contents of my duffle bag (full of 7-Eleven store goodies) and run out to meet my opponent (who probably just did the same thing).

Then in my fourth year of college, I didn’t seem to have enough time to get all the work done, trying to complete a double major and applying to dental and medical schools. I restricted sleep to only every other night, and I skipped breakfast and lunch. I didn’t like sleeping only every other night, but I guess I didn’t mind eating only one meal a day, because 30 years later, I’m still eat one meal a day (dinner). It really does save a lot time.

So what does the published medical literature say about intermittent fasting. In laboratory animals, caloric restriction (while avoiding malnutrition) has positive beneficial effects in seemingly every disease condition tested, including cancer. The animals also lived longer. Finding the same effect in humans has been more complicated. True, caloric restriction in overweight or obese humans has had beneficial effects on many diseases, but there was always accompanying weight loss. Do we give credit to the fasting, or to the weight loss? It’s impossible to say; I suspect the latter. Reportedly, clinical trials are underway, looking to see if fasting by itself has a beneficial effect in humans. These studies will have to enroll humans who are not obese or overweight and who will not lose weight as a result of the intervention. So until then, we really don’t know.

But I will leave you with a favorite study of mine. Patients were overweight, and were randomized to one of two groups. Group 1 was prescribed 3 meals a day. Group 2 was prescribed 2 meals a day. The total number of calories prescribed in both groups was equal. After several weeks, patients in both groups lost weight. But group 2 patients lost more weight and felt more satisfied and less hungry. Too bad they didn’t have a “Group 3” – 1 meal a day. That would have been interesting.

And getting back to cancer, studies have suggested that obesity is linked to higher rates of all cancers. I do believe that treating cancer is a team approach the surgeon, the oncologist, and most of all the patient (who contributes by optimizing the things under his/her control, e.g., being at a healthy weight).