Our Longevity Diet

In the past I’ve heard several claims that intermittent fasting can help prevent cancer, but in following the scientific literature, I’ve seen little evidence behind this claim. Now, someone from a discussion group brought this study to my attention:

Adult-onset calorie restriction and fasting delay spontaneous tumorigenesis in p53-deficient mice

Basically, the study not only shows that both calorie restriction and fasting can help make significant delays in the onset of cancer in mice bread to develop that disease (that’s what the p53 deficient part means), but they also show that the effect is present even when the calorie restriction or intermittent fasting is started later in life, rather than at adolescence. Too many of the existing studies of CR and IF look at the effects on animals that begin in adolescence and continue throughout their lives. I’d like to see more studies examine the effect of starting these dietary protocols later in life, and also the effect of starting early in life but then abandoning the protocol to return to ‘normal’ (i.e. continuous) eating.

And while the study shows cancer was ‘delayed’ rather than prevented, the difference is only semantic. Delay cancer long enough that you die of something else, and it has effectively been prevented. The mice were genetically prone to develop cancer — unless you have Li-Fraumeni Syndrome you are probably not so prone.

This study did show that calorie restriction was more effective than intermittent fasting, but the intermittent fasting regime used involved fasting just one day per week — it would be more interesting to see the results if ADF (alternate day fasting) were used. The bottom line seems to be that it is never too late to start benefiting from intermittent fasting. The beneficial effects are probably much stronger for those who start in early adulthood, but even us old fogies can reap some benefits.