An Interview with Valter Longo on Intermittent Fasting

Researcher Valter Longo is presently working on, among other things, packaging up intermittent fasting as a treatment with the sort of rigor needed to get it through clinical trials with the FDA. The work leading up the clinical trials involved putting numbers to the short term term benefits provided by fasting: how often and how long must someone fast in order to achieve specific changes in biomarkers of health, and how long do those effects last? The data will be useful for people who practice intermittent fasting as a health strategy, moving the state of scientific support for this strategy closer to that existing for the practice of calorie restriction with optimal nutrition.

Calorie restriction is a very wide-ranging word. We focus more on periodic fasting - we're not really big believers in having people be on special diets or restrictions all the time. We just believe in interventions that are short and lasting, that can last a long time and protect from aging and age-related diseases. But also the use of these in improving disease treatment.

It has been very effective. Originally we did this in simple organisms to understand the molecular basis for it, and then moved to mice, and now we're finishing a number of clinical trials. The effects have been very, very promising. Most of it is not published in humans yet but a lot of it is already finished. So in the next year or so we're going to have at least 3 papers and clinical trials showing normal subjects, cancer subjects and also other diseases, showing the efficacy of these techniques, but also the high compliance that we get in doing this. So it's really something that we've found that most people can do.

As soon as the clinical trial is over basically that's it - people can start doing it. Now for the cancer one people could do it, but not to treat the cancer, only to reduce the side effects of chemotherapy. The cancer itself is regulated by the FDA so we'll have to continue our trials until these are FDA approved if we want to have the treatment included in therapy for delaying cancer progression. But of course people will do it anyway, because if you can use it with chemo obviously you're already using it to treat cancer but you just can't say.

The reduction of IGF-1 is really key in the anti-aging effects of some of the interventions. Both the dietary ones and the genetic ones. We've been putting a lot of work into mutations of the growth hormone receptor that are well established now to release IGF-1 and also cause a record life span extension in mice. So we know for example with chemotherapy resistance if you fast mice and inject IGF-1 you reverse a lot of the protective effects of fasting. So it's important; it's not the only factor, but it's certainly one of the key ones.