Fasting

In The Economist of June 20^th, there was an interesting article under the heading “Do longevity drugs work.” The subtitle was that animal studies suggest that certain drugs are no more effective than long-term fasting.  The article was comparing a series of pharmaceutical drugs that are being touted as guaranteeing longevity.

“As elixirs of life go, long-term fasting is the surprising candidate. Yet it seems to work. Experiments on species from worms to monkeys show that near starvation prolongs lifespan. And although no long-term experiment has been conducted to prove the same is true of Homo Sapiens, short term ones suggest similar physiological changes do happen.”

I found this particularly relevant now as we have entered the three-weeks between the 17th day of Tamuz and the 9th Day of Av, a period of mourning for the destruction of both temples and Jerusalem which starts and ends with fasts. Fasts don’t seem to have been such a big thing in the Torah. Not one mention. Even Yom Kipur is not described as a fast but rather a Day of Affliction. 

But the catastrophes of our self-destruction ( helped by Babylonians and Romans) resulted in many more. A whole Tractate of the Talmud is devoted to fasts. Not just for atonement but for all kinds of catastrophes of which the most common was failure of the rains and even bad dreams. But medieval persecutions, particularly the Crusades,  led to many different local fasts commemorating massacres. Excessive penance and self-denial in celibate Christianity had an influence on us too. We added optional fasts ( BeHab) on the Monday, Thursday and Mondays after festivals to make up for too much gluttony on the festivals themselves.

But the fasts over the loss of the Temple and Jerusalem came to dominate because the events affected every corner of Jewish life. We have just had the Seventeenth of Tamuz. 

The Mishna ( Taanit 4:6) gives various reasons for the fast of the Seventeenth of Tamuz ranging from when Moses broke the two Tablets of Stone to the beginning of the destruction of Jerusalem and the temple. And one may wonder why we don’t add one for the Holocaust. A matter I shall return to nearer the Ninth of Av.

My magnificent father who was in general strict on matters of ritual, would say that if a minor fast gets in the way of studying Torah or if it becomes merely an endurance test to see what a good person you are, one should rather prioritize by doing something positive rather than negative and minor fasts could be treated leniently. And he said such opinions were common in the Yeshivas of Lithuania. Of course, in our day and age you will not get any Orthodox rabbinic leader who would take such a lenient point of view in public. 

I have always had a problem fasting. Some people seem to be able to take to it like ducks to water and it has very little effect. But not me. It affects my concentration and ability to use time more productively. The strange thing is that when it comes to Yom Kippur which is a 25 hour fast, I seem to be able to manage it without too much trouble. Yet when it comes to minor fasts, I have great difficulty and struggle to get through the day. Although since I come out fine on the other side with no serious damage and quite the contrary having lost a pound or two in the process, it seems my anxiety may be psychosomatic.

But now having read that fasting is good for you I’m inclined to take the minor fasts much more seriously than I ever did before. And not only that, but as at this particular moment the dysfunctionality, hatred , violence, and ignorance that seems to be on display everywhere, I want to make a plea for taking the minor fasts a little more seriously and it might even add a few more years to our lives, to boot.

But let me not get carried away. The article about fasting being good for you ends with this sentence. 

“As for mere mortals who want a long and healthy life without the risk of drug side effects the advice remains the same, eat wisely, drink moderately, exercise regularly, sleep well .”

Jeremy Rosen

July 2025