FoundMyFitness · 2017-10-30 · Rhonda Patrick (host), Satchidananda Panda

Dr. Satchin Panda on Practical Implementation of Time-Restricted Eating & Shift Work Strategies

62 claims checked against research: 1 contradicted 2 overstated 3 needing context 53 supported 3 unverified

Overstated

0:09:14 Satchidananda Pandaoverstatedlow

Eating within two to three hours before bed directs blood flow to the stomach and keeps core body temperature elevated, impairing deep sleep.

"towards the end of the day when we are going to hit the bed, if we have food in our system, what happens is blood flow is directed towards our stomach to digest the food and absorb it, so core body temperature remains high. So not having food for two to three hours before going to bed, it actually helps us to have that deep sleep, sound sleep throughout the night." (said at 0:09:14)

While observational studies link eating close to bedtime with poorer subjective sleep quality, longer sleep latency, and nighttime awakenings, controlled laboratory polysomnography trials show mixed effects on sleep architecture rather than a straightforward suppression of deep sleep. In a randomized crossover trial of healthy adults comparing dinner 1 hour versus 5 hours before bedtime, eating 1 hour before bed did not impair total slow-wave sleep and actually produced an initial increase in delta power (deep sleep) in the early part of the night, followed by lighter sleep later in the night. The proposed mechanistic explanation—that splanchnic blood flow and postprandial thermogenesis keep core temperature elevated in a manner that impairs deep sleep throughout the night—is an oversimplification of complex postprandial sleep and circadian dynamics.

partial: Relationship between food intake and sleep pattern in healthy individuals. (Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine 2011) · cited 200x in the literature
"We conclude that food intake during the nocturnal period is correlated with negative effects on the sleep quality of healthy individuals. Indeed, food intake near the sleeping period (dinner and late night snack) was negatively associated with sleep quality variables." (abstract, conclusions, passage verified)
pubmed full study (doi)
contradicts: Effects of Dinner Timing on Sleep Stage Distribution and EEG Power Spectrum in Healthy Vol… (Nature and science of sleep 2021) · cited 31x in the literature
"Contrary to the existing literature, shifting dinner timing from 5 hours before sleep to 1 hour before sleep in healthy volunteers did not result in significant adverse changes in overnight sleep architecture. In fact, LD was associated with deeper sleep in the beginning of the night and lighter sleep in the latter part of the night in healthy volunteers." (abstract, conclusions, passage verified)
pubmed full study (doi)

1:05:35 Satchidananda Pandaoverstatedvery low

Hair follicle bulb cells possess a circadian rhythm that repairs damaged DNA every evening to support next-day hair growth.

"So we went back and checked, and we realized that the hair follicle bulbs, at the base of the hair, actually have a very strong circadian rhythm. And every evening, that circadian clock repairs all the damaged DNA and makes sure that the hair can grow back next day, next morning." (said at 1:05:35)

A 2013 mouse study demonstrated that the circadian clock in hair follicle bulb cells (epithelial matrix and dermal papilla) regulates a daily mitotic rhythm. Mitosis peaked in the morning, leading to faster morning hair growth, while evening gating at the G2/M cell cycle checkpoint rendered hair follicles significantly less susceptible to genotoxic DNA damage (such as gamma radiation). While the circadian clock does regulate cell-cycle checkpoints and diurnal sensitivity to DNA damage in hair follicle cells, describing this as a clock that 'repairs all the damaged DNA every evening' to ensure next-day growth overstates the specific mechanism and extrapolates mouse model findings to humans.

partial: Local circadian clock gates cell cycle progression of transient amplifying cells during re… (Proceedings of the National Academy of Sciences of the United States of America 2013) · cited 158x in the literature
"We identified two key sites of peripheral circadian clock activity specific to regenerating anagen hair follicles, namely epithelial matrix and mesenchymal dermal papilla. We showed that peripheral circadian clock in epithelial matrix cells generates prominent daily mitotic rhythm. As a consequence of this mitotic rhythmicity, hairs grow faster in the morning than in the evening. Because cells are the most susceptible to DNA damage during mitosis, this cycle leads to a remarkable time-of-day-dependent sensitivity of growing hair follicles to genotoxic stress. Same doses of γ-radiation caused dramatic hair loss in wild-type mice when administered in the morning, during mitotic peak, compared with the evening, when hair loss is minimal." (abstract, results, passage verified)
pubmed full study (doi)

Unverified means no publication matching the claim was located; it does not prove the claim false. Spotted an error? See the corrections policy - disputes from the people quoted are prioritized.