Shift work as a carcinogen and how time-restricted eating may help | Satchin Panda
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Just over a decade ago, the International Agency for Research on Cancer, which is part of the World Health Organization, classified shift work as a probable human carcinogen. Investigating the ways in which shift work affects the human body and how it increases cancer risk presents many challenges due to shift work's inherent heterogeneity. Essentially, not all shift work is created equal, with some people working long shifts, others working short ones, and some alternating between day and night shifts. Time-restricted eating, which limits the number of hours during which a person eats, is emerging as a means to offset some of the deleterious effects of shift work. In this clip, Dr. Satchin Panda describes some of the challenges associated with studying the effects of shift work and how time-restricted eating might benefit those who work shifts.
-Satchin: And then there also is mounting evidence all over the world that shift work is tightly linked or increases the risk of certain kinds of cancers, including breast cancer. So that's why World Health Organization has categorized shift work as a potential carcinogen. So that's a very serious classification because if we know that we have to stay away from carcinogens, even in buildings, if there is a carcinogen, there's a potential carcinogen used as a paint or there is a reason, then we have to put a sticker. And to think about shift workers, they are actually doing something that's a potential carcinogen. They do it almost on a daily basis for many, many years. So that's why I think now there is increasing awareness how to manage shift work so that they will stay healthy and will reduce the risk of disease. - Rhonda: And they're doing something beneficial. I mean firefighters, nurses, you know, police. I mean they're helping society, so it's not like you can just eliminate shift work, right? I mean you need shift work. - Satchin: No, actually our modern society is actually based on those heroes. So we actually call them the guardians of our society because they are the ones in the middle of the night, they are making the economy running, they are the ones who are hauling trucks, long distance trucks, and they are the ones who are actually transporting cargoes of a plane or ships. They are the ones in the middle of the night that are taking care of our health and to any emergency. So we have to kind of make sure that these heroes are healthy. So we have to kind of start thinking how to come up with a healthy heroes program where we can clearly say these are the lifestyles that they can adopt in relation to their being productive at work so that they stay healthy. And one complexity with shift work is shift work is just not one type of shift, it's a mixture of many different types of shifts. And, for example, firefighters may be on shift for 24 hours straight, whereas a nurse is on shift for only 12 hours. Some of the first responders may be on shift only for eight hours. And then for them, for some of them, the shift might change two or three times within a month, so they may be on a day shift versus night shift, even within the same week. Whereas in some departments and in some professions they can be on the same shift for three to four months, which helps them to adapt to that shift. So in that way I think it will be interesting to bring up this heterogeneity in shift work and figure out which kind of shift work is more manageable than others and perhaps figure out how we can help, firefighter kind of shift work versus nurse kind of shift work and first responders. - Rhonda: Yeah. Do we know from any animal evidence... For example if you take an animal that is, you know, for example, nocturnal, like a rodent, a mouse, which usually eats at night, you force it to now not eat at night but to be awake during the day and eat at day and not eat at night. So if you can shift them to not eat all day, all night, but eat just within a time-restricted eating window, do we know if they eventually adjust, how long it takes for them to adjust? Does their metabolism adjust? Does their circadian rhythm adjust? - Satchin: Yeah, so those studies have been done and there are many different ways to look at it. One is if we just give the same unhealthy high fat, high sucrose diet, instead of giving them at nighttime for 10 hours, for example, give them during daytime when they're not supposed to eat, when they're supposed to sleep. So the bottom line is if mice eat randomly, then any kind of time-restricted eating is better than that random eating. So even if they eat during daytime for 10 hours, that still gives them some benefits. So it's still beneficial. So there are some concerns with animal experiments. One is if we feed animals during daytime, definitely they lose some sleep and they just eat. Unlike shift workers, they're actually not working throughout the daytime, unless we force them to really work. So then it becomes a two-factor intervention. And then at nighttime when they actually go back to their normal activity, they run around in the cage. So in that way they get a sleep deprivation pattern factor into it. So they are not as healthy as night-fed mice, but at the same time they have a strong sleep deprivation factor. So that's why I think among shift workers, coming back to shift workers, if we can control for how much they sleep during their off time and they can sleep enough, if they come up with some sleep hygiene and adopt some sleep rituals that help them, and then they adopt the eating pattern that best suits their shift, then it might help. - Rhonda: But eating still within a small, more narrow window. - Satchin: Yeah, still eating within a narrow window.
The process by which cancer is initiated and normal cells are transformed into abnormal cells. In order for a normal cell to transform into a cancer cell, genes that regulate cell growth and differentiation must be altered. DNA damage is a well-known initiator of cancer because it can lead to cancer-causing mutations.
The body’s 24-hour cycles of biological, hormonal, and behavioral patterns. Circadian rhythms modulate a wide array of physiological processes, including the body’s production of hormones that regulate sleep, hunger, metabolism, and others, ultimately influencing body weight, performance, and susceptibility to disease. As much as 80 percent of gene expression in mammals is under circadian control, including genes in the brain, liver, and muscle.[1] Consequently, circadian rhythmicity may have profound implications for human healthspan.
- ^ Dkhissi-Benyahya, Ouria; Chang, Max; Mure, Ludovic S; Benegiamo, Giorgia; Panda, Satchidananda; Le, Hiep D., et al. (2018). Diurnal Transcriptome Atlas Of A Primate Across Major Neural And Peripheral Tissues Science 359, 6381.
The thousands of biochemical processes that run all of the various cellular processes that produce energy. Since energy generation is so fundamental to all other processes, in some cases the word metabolism may refer more broadly to the sum of all chemical reactions in the cell.
A person who works on a schedule outside the traditional 9 AM – 5 PM day. Work can involve evening or night shifts, early morning shifts, and rotating shifts. Many industries rely heavily on shift work, and millions of people work in jobs that require shift schedules.
Restricting the timing of food intake to certain hours of the day (typically within an 8- to 12-hour time window that begins with the first food or non-water drink) without an overt attempt to reduce caloric intake. TRE is a type of intermittent fasting. It may trigger some beneficial health effects, such as reduced fat mass, increased lean muscle mass, reduced inflammation, improved heart function with age, increased mitochondrial volume, ketone body production, improved repair processes, and aerobic endurance improvements. Some of these effects still need to be replicated in human trials.
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- After exposure to daytime bright light (6.5 hours), evening use of a tablet for two hours did not affect sleep in healthy young students.
- Acid Suspends the Circadian Clock in Hypoxia through Inhibition of mTOR. - PubMed - NCBI
