Fasting simply means not eating. Not eating for 12 hours or more - skipping breakfast can be a good start for people new to fasting. But the real benefits of fasting begin when the body has used most of its glucose supplies. This happens at about 24 hours. Days long fasting is something you might want to try but this is a different discussion.
Fasting releases a cascade of hormones and signaling chemicals that is good for the brain. Maybe the most dramatic new discovery relates to brain derived neurotropic factor (BDNF). This hormone-like protein promotes brain plasticity and new brain cell formation. The research into BDNF was first popularized by neuroscientist Mark Mattson in his TED talk.
Research shows that BDNF signals stem cells to grow new brain cells in certain parts of the brain connected to memory. It also promotes synaptic connections through out the nervous system. Making new connections is important for any kind of learning.
An understanding that fasting helps with brain function is not new. The ancient Romans discovered that people with epilepsy reduced their seizures when fasting. Many people talk about fasting clearing up brain fog. The exact reasons for this are under research but it is likely related to the increase in ketone bodies and BDNF that are activated when we challenge the brain through fasting or exercise.
Fasting also signals the nervous system to increases mitochondrion production in brain cells. Mitochondria are the cell's energy organelles. We can assume that more brain energy will elevate our mood and resilience.
Fasting also helps with the repair mechanisms in the brain and nervous system by helping to "clean up" the broken proteins and inflammation that appear in the aging brain. This cleaning up can also help increase neuroplasticity and memory and likely reduces the chances for age related neurodegenerative diseases such as Azheimer's and Parkinson's disease.
Also, BDNF, and other neurochemicals triggered by fasting have been associated with helping a wide spectrum of other mental diseases such as depression and schizophrenia.
Will fasting cure everything? Obviously, if you are already undernourished fasting might not work for you. People should also be careful if they are taking medications that lower blood sugar.
As mentioned above exercise has also been shown to increase BDNF. So there are alternatives to fasting.
But intermittent and longer fasting might be the most powerful way of helping brain health.
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