Intermittent Fasting: Resetting Circadian Rhythms, Reducing Inflammation, and Boosting Mental Health

This podcast episode, hosted by DocSnipes, delves into the multifaceted impacts of intermittent fasting (IF) on the body and brain, defining it as a dietary pattern rooted in evolutionary biology where the body adapts to function efficiently in a fasted state. It primarily discusses two types: time-restricted feeding (TRF), which involves daily fasting windows of at least 14 hours, and alternate-day fasting (ADF), where individuals consume 25% of their caloric needs on fasting days. The core mechanism highlighted is the 'glucose to ketone switchover,' where the body transitions from using glucose to ketones (derived from fat) as its primary fuel source, leading to enhanced resistance to stress, injury, disease, and improved cognitive and physical performance.

The episode elaborates on significant metabolic and physiological changes induced by IF, including improved blood pressure, cholesterol levels, and wound healing. Brain health is boosted through the release of Brain-Derived Neurotrophic Factor (BDNF), promoting neurogenesis and neuroprotection, and enhancing the brain's ability to seamlessly switch between glucose and ketone energy sources. IF also positively modulates circadian rhythms, with feeding times influencing the body's internal clock and hormone regulation. Furthermore, it significantly reduces systemic inflammation by lowering pro-inflammatory markers like homocysteine, interleukin-6, and C-reactive proteins, and positively impacts the gut microbiome.

DocSnipes explores IF's potential therapeutic applications across a wide range of conditions, including Alzheimer's and dementias, various autoimmune disorders (Crohn's, colitis, rheumatoid arthritis), cancer (by increasing adiponectin levels), heart disease (reducing atherosclerosis), chronic pain (by increasing endogenous endorphins and monoamines like serotonin, norepinephrine, and dopamine), epilepsy, fibromyalgia, polycystic ovarian syndrome (PCOS), Parkinson's disease, and sleep phase disorders. The increase in mood-regulating neurotransmitters is particularly emphasized, with studies showing mood improvement within 7-10 days, contrasting with the longer onset of traditional antidepressants.

Crucially, the episode stresses that IF is a lifestyle change, not a temporary fix, and its benefits persist only with continued practice. It also outlines important contraindications, advising caution and medical consultation for individuals with diabetes, cardiovascular disease, mood disorders (especially bipolar and schizophrenia due to mixed evidence and potential for relapse), pregnancy, and a history of eating disorders, as IF can exacerbate obsessive tendencies. The timing and duration of fasting windows should be personalized and discussed with a medical team to optimize benefits and mitigate risks.

"during evolution people whose brains and bodies functioned well in a fasted state were more successful in acquiring food for survival and reproduction"

"the body can switch to a cellular fuel source of the ketones instead of using glucose which causes adaptations in the body and brain that they found enhance the body's resistance to stress injury and disease and even enhances cognitive and physical performance in the fasted state"

"for intermittent fasting to be effective for most people the fasting window should be at least 14 hours"

"intermittent fasting strengthens our ability or makes our body more effective and efficient at switching over fuel sources"

"this isn't something that somebody can do for a month or even three months and then go back to their old habits and have the changes persist it's something that we're really looking at as a lifestyle"

"BDNF actually helps protect or buffer against those excitatory neural chemicals so we see neuroprotection instead"

"intermittent fasting has been shown to increase levels of serotonin norepinephrine and dopamine"

"intermittent fasting in a couple of studies was shown to increase mood and perceptions of well-being within seven to ten days of starting the intermittent fasting protocol as opposed to antidepressants which can take up to six weeks"

"the timing and amount of fasting impacts different cancers in different people so it's something definitely to discuss with your oncologist"

"intermittent fasting promotes a regular cycle of feeding and fasting which helps set your circadian rhythms including hormones like cortisol ghrelin and leptin your hunger and satiation hormones and testosterone"