Does drinking coffee break your fast? | Satchin Panda
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Caffeine – especially when consumed early in the morning – resets the body's internal clocks and provides a mental boost that helps us start the day. But how caffeine affects our circadian rhythms at other times of the day and whether it influences various aspects of our metabolism during time-restricted eating are not well understood. Although some evidence suggests that black, caffeinated coffee or tea may have little effect on the beneficial effects associated with time-restricted eating, experts in the field of circadian biology suggest a more conservative approach that permits coffee and tea only during the designated window of eating. In this clip, Dr. Satchin Panda discusses the controversy surrounding consumption of black coffee or tea while practicing time-restricted eating.
- Rhonda: The other thing that is sort of on this whole fasting versus TRE topic that gets asked a lot that I have to ask you has to do with coffee. Actually, specifically caffeine, like black coffee. So without any cream or any calories or anything like that. So caffeine can start things, like the clocks in your liver?
- Satchin: Yeah, it resets the clock. Because the clock is always running, it just resets.
- Rhonda: It resets it, okay. So a lot of people in the intermittent fasting community, they do a lot of fasting, whether, you know, they're fasting for 16, 24 hours, 48 hours, but they drink caffeine and they notice that they lose weight. And so they say, "Well, I'm still getting results."
- Satchin: Yeah.
- Rhonda: You know, "So it's fine, I can drink my black coffee."
- Satchin: Yeah.
- Rhonda: You know, obviously someone that's fasting for 48 hours, it's very different than doing the TRE schedule where you're eating for 10 hours a day or 11 hours a day, and then fasting for, you know, 13 or 14 hours every night, right?
- Satchin: Yeah.
- Rhonda: So if a person, for example, that wakes up in the morning drinks black coffee at 7:00 a.m. They wake up, have some black coffee at 7:00 a.m. But they don't eat anything, they don't eat their first bite of food until...
- Satchin: 10:00 or 11:00.
- Rhonda: Yeah. Yeah, something. Then when do they have to stop eating by? Like, is it when the coffee started or is it when they ate the food?
- Satchin: Yeah, so this is a question we also get through the app a lot. And we actually posted a blog on our website. So here is a very different thing. So since we look at circadian rhythm as a whole, it has a sleep component, food component, exercise or activity component. And we know that caffeine resets the body clock. So, for example, drinking a cup of coffee is similar to having exposure to bright light for an hour or hour and a half. So that's just on the circadian clock itself. Now the question is, "Well, will it reset that clock the same way if the coffee comes in the morning versus evening or night?" And we know that there is a term called phase response curve. So that means the same light, it relates to light. The same light will reset the clock differently at different times of the day. During daytime when your system is expecting light, if you're in a dark room and we see light it doesn't reset our clock. But in nighttime it will reset our clock. So we don't know what is the phase response curve for coffee, whether it resets much more at certain times and less at other times. The direct impact of coffee on clock is unknown. Then the second thing that relates to coffee is sleep because coffee definitely suppresses sleep in a lot of people, some people may be resistant. And the reason why we drink coffee is we wake up, we get up from the bed, but we maybe are still feeling sleepy. We want to get that extra energy, that's why we drink coffee. And along that line, of course, drinking coffee at night is a straight no-no because it will have impact on sleep. But in the morning we ask the other question, "Are you drinking coffee because you did not rest well, you did not rest enough?" So maybe that's why you need coffee to reset your mental clock, or brain clock, to start it. And sometimes it can be just a pure habit or addiction. For example, I used to like coffee in the morning, and then I realized, "Well, let's get rid of coffee. What happens?" Maybe for the first two or three days I got a headache, and then now I'm used to drinking just hot water. It's just the feeling of sipping something from a sippy cup. It's almost like a baby sipping something from a sippy cup. And I realized that that's what I was addicted to. I can actually substitute coffee with hot water and nothing changed. I still felt energetic after my hot water and I realized that that was my addiction.
- Rhonda: After you got over the...
- Satchin: After I got over the first two days of headache.
- Rhonda: ...withdraw.
- Satchin: Yeah, withdraw symptoms. And then it's always [Inaudible] the question of metabolism. When we drink coffee, is it going to trigger metabolism or certain things in our gut so that the gut will think, "Well, now I have to start working, the rest is over"? And we think that's where the metabolism or the function of the gut to absorb, or digest this coffee, send that caffeine to liver, and then to brain does kick start right after we drink coffee. Because that's how we are feeling the effect of coffee in the rest our body, because the stomach started working, it absorbed coffee, it sent it to liver, liver might have metabolized it slightly and started to send it to the rest of the brain and body. And then it gets back to kidney, it gets metabolized and excreted. So then the question is, forget about circadian clock, now if we think about just metabolism and, say, mitochondria function, or even, say, go back to autophagy, and then ask, "Is caffeine breaking the fasting so that it stops autophagy, or it stops something else? Or is there a crosstalk between, say, caffeine receptor and glucagon receptor so that it does, "No, fasting is kind of slightly over." You may not be in 100% fast, but in 40% or 50% fast. So that's where things become murky, so that's why we say, "Well, if you can, drink your coffee within this 8-hour, 10-hour, it's better." But at the same time we know, going back to the study that we discussed, Ruth Patterson study, they did not consider coffee as food. So when they considered 13 hours overnight fasting, that 13 hours actually included coffee and tea. So in that we know for cancer, reducing breast cancer risk, this 13 hours of fasting can include coffee, black coffee, and tea. So this is where things are really murky. And we tend to error on the safe side, so we tell, well, if you can have that coffee within your eating window, that's much better. If you can't, then just have black coffee. At least that will not trigger your insulin response or glucose response. So that's what we do, we recommend.
An intracellular degradation system involved in the disassembly and recycling of unnecessary or dysfunctional cellular components. Autophagy participates in cell death, a process known as autophagic dell death. Prolonged fasting is a robust initiator of autophagy and may help protect against cancer and even aging by reducing the burden of abnormal cells.
The relationship between autophagy and cancer is complex, however. Autophagy may prevent the survival of pre-malignant cells, but can also be hijacked as a malignant adaptation by cancer, providing a useful means to scavenge resources needed for further growth.
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.
A hormone produced by the pancreas that works with insulin to regulate blood glucose levels. While insulin decreases blood glucose levels when it is too high, glucagon increases the concentration of glucose in the bloodstream when glucose in the bloodstream falls too low. Glucagon causes the liver to convert stored glycogen into glucose. Glucagon increases energy expenditure and is elevated under conditions of stress.
A peptide hormone secreted by the beta cells of the pancreatic islets cells. Insulin maintains normal blood glucose levels by facilitating the uptake of glucose into cells; regulating carbohydrate, lipid, and protein metabolism; and promoting cell division and growth. Insulin resistance, a characteristic of type 2 diabetes, is a condition in which normal insulin levels do not produce a biological response, which can lead to high blood glucose levels.
A broad term that describes periods of voluntary abstention from food and (non-water) drinks, lasting several hours to days. Depending on the length of the fasting period and a variety of other factors, intermittent fasting may promote certain beneficial metabolic processes, such as the increased production of ketones due to the use of stored fat as an energy source. The phrase “intermittent fasting” may refer to any of the following:
- Time-restricted eating
- Alternate-day fasting
- Periodic fasting (multi-day)
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.
Tiny organelles inside cells that produce energy in the presence of oxygen. Mitochondria are referred to as the "powerhouses of the cell" because of their role in the production of ATP (adenosine triphosphate). Mitochondria are continuously undergoing a process of self-renewal known as mitophagy in order to repair damage that occurs during their energy-generating activities.
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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