This week, I will be going on a short 5-day water fast. Here’s why:
We evolved as a species in an environment where food was not available all of the time, refrigerated and waiting for us to graze upon. It is said while we were evolving as hunter-gathers, we spent about 95% of our time searching for food. (The other 5% was spent reproducing.) Basically, we are not built to be shoveling food into our bodies from the time we wake up until the time we go to sleep, and our disease rate increases reflect this.
Because of the enormously long time (100,000 generations) we spent as hunter-gathers, we have within us physiological and behavioral responses that are activated when we must go without food. As modern humans we can tap into these evolutionary responses by fasting occasionally and giving our bodies a reminder of an earlier time that only our cells remember. This lecture by Mark Mattson is about his team’s research into the link between modern health and these evolutionary responses.
They have shown that intermittent energy restriction (IER) along with vigorous exercise, can increase numbers and strength of synapses and can enhance brain function and mood. IER is fasting – for a block of days, for a period of 24 hours several times each week, or by limiting our intake times to fewer hours daily. The two activities – IER and exercise – increase the neuron activation state and energy demand, which results in:
- Production of brain-derived neurotrophic factor (BDNF) – I want more of this because it encourages the growth, regeneration and creation of new neurons and synapses
- Mitochondrial replication – I want more of these because they produce energy and keep me young
- Enhanced autophagy – I want this because it is the removal of oxidatively damaged proteins. (Just as an aside, the 2016 Nobel Prize in Medicine was awarded to Yoshinori Ohsumi for work in this field, and his Nobel lecture is available online.)
- Reduced inflammation – I want this reduced because inflammation is wearing on my mitochondria and another “yank on the genetic chain”
- Peripheral changes in energy metabolism that occur during fasting (and exercise) may also contribute to a healthy brain.
Fasting has been called the single most profound metabolic intervention for modern health.
I am about to find out!