It would be especially harmful if we ended up suppressing the processes that make you feel sleepy when you need sleep, while the harmful effects of sleeplessness remained.
Now here's the kicker. When your body builds 'tolerance' for caffeine, what this usually means* is the post-synaptic cell adjusts how much adenosine it's pumping out so that the "I'm tired" signal can cut through the caffeine. And when you go through caffeine withdrawal, it takes a while for those levels to re-adjust to normal.
* in the brain. Caffeine also has effects on your digestive tract, blood pressure, and some other non-brain parts. :)
Edit: corrected cAMP -> adenosine (simple recall error from a lecture that was 9 years ago). The gist of the reply remains the same.
Caffeine is more like an adenine analog, not a cAMP (3'-5' cyclic adenosine monophosphate) analog. It binds adenosine receptors, not primarily cAMP receptors. It has indirect effects on cAMP, but I am not aware of direct ones. Also, your description of cAMP signaling sounds confused, since cAMP is an intracellular second messenger. I am not aware of an extracellular retrograde signaling process for this molecule.
Sorry, and your implication that cAMP is a byproduct of ATP consumption is totally wrong. cAMP is synthesized directly from ATP, a reaction catalyzed by the regulated enzyme adenylate cyclase.
(My thesis was on auditory cognition and I haven't touched ion channel biophysics in that long. I have a long-ago memory that adenosine (now corrected) operated as a retrograde transmitter, though since I'm probably not going to spend my afternoon looking for the citations, I'll delete as well for now. Not because I believe it's wrong, just that I can't immediately back it up.)
Are you still doing research yourself or have you left for startup land like most of HN?
since bioscience isn't on my radar i'm not sure if you'd find anything useful there, however, it feels like a more concentrated version of HN which specializes in some of the other stuff that interests you (e.g. learning algos, data analysis, etc.).
"Caffeine competitively inhibits phosphodiesterase, the enzyme that degrades cyclic AMP...By blocking the degradation process of cyclic AMP, caffeine indirectly affects regulation of cAMP-dependent protein kinases". TIL.
In moments of weakness and pushing a deadline, I have sometimes rationalize the trade-off of future time/health to present time, and sometimes, that sticks me with tolerance that it takes time to wean off. I have made a conscious effort to quit caffeine dozens of times in my life, and the most recent time it has stuck, and I plan to stick with it. The thing is, when I gain "time" with caffeine, it's not necessarily time with high-quality cognition or productivity compared to my well-rested self, and it's easy to forget to take that into account when you're making trade-off decisions when tired. You still perform like a tired person, you're just not subjectively feeling the tiredness.
FWIW, drinking decaf gives you the health benefits of coffee with 5% (kinda negligible) amounts of caffeine.
That said, a lot of the risky solvents used in the usual methods of making decaf are no longer commercially used these days, so I don't think there's a serious health risk in drinking any ol' decaf you want.
Notes for below:
* CHB/CHC -> chronic hepatitis B/C
* NAFLD -> Non-alcoholic fatty liver disease
When discussing possible mechanisms for their findings:
"We postulate that the observation of the benefit of coffee on the progression of liver disease may be due to its effects on the oxidative stress/lipotoxicity pathway, which underlie the pathogenesis of cirrhosis related to alcohol, NAFLD and possibly, in part, CHC. However, since oxidative stress is not the predominant mechanism of injury seen in CHB, coffee has no beneficial effect. Polyphenols and melanoidins, which are major components of coffee, have been shown to mediate multiple protective mechanisms in a rat model of steatohepatitis, ranging from increased fatty acid β oxidation, mitigating oxidative stress and curtailing liver inflammation (47). The other components of coffee, cafestol and kahwoel, can induce phase II detoxifying enzymes, including sulfotransferase, UDP-glucuronosyl transferase, glutathione transferase and peroxidase, and thus contribute to the anti-oxidant properties of coffee (14, 48). In addition, chemicals in coffee such as polyphenols and the diterpenes have been shown to down-regulate proinflammatory, fibrogenic cytokines such as transforming growth factor beta (TGF-β) and its downstream modulator, connective tissue growth factor (CTGF), collagen and stellate cell activation (13–16).
Epidemiologic studies on caffeine have been inconsistent in demonstrating a protective effect in liver disease since other caffeine-containing beverages such as tea have not shown to be protective (19–21). Similarly, in our study, the inverse association with caffeine became null after adjustment for coffee, suggesting that ingredients of coffee other than caffeine appear to be responsible for this beverage’s effect on risk reduction. Furthermore, other caffeine-containing beverages like green tea and black tea had no significant effects with cirrhosis mortality in this study."
Is there any information (affirmative or negative) about Modafinil's effects on this plaque? Considering how recent this whole discovery seems to be, I doubt there's much conclusive info on this specific interaction.
You'll probably fall asleep earlier in the day, but you'll only sleep for 8 hours. This is why it's useful for offsetting your rhythm.
Ritalin/Adderall is very different. If you use it to stay up for 8 hours, you'll sleep for 16 hours the next time you pass out.
Again, though, the data is ambiguous AFAIK.
From my subjective experience, this isn't necessarily true. All-nighters with modafinil vs. all-nighters with adderall require the same amount of catch-up sleep for me. Modafinil just gives me a less jittery wakefulness.
I tend to prefer to use it to offset sleep for relatively short periods - e.g. get an extra night of work, and then sleep a bit longer for the next couple of nights - as I feel it's more productive to get a longer block of time where I'm fully alert, and give up late evenings when I'd feel tired anyway to recover.
In my opinion, efficiently using our current methods for deferring sleep boils down to understanding that you're merely deferring it, and using it to "schedule" your most awake/concentrated periods when you need it most, rather than try to force yourself to work well all the time.
Maybe one day we have something that can let us cut sleep entirely, but we're still far away from that.
EDIT: As I've clarified in another comment below, my sleep amounts without anything are already fairly low, and that may certainly affect my ability to push it further down with modafinil over the long term.
It also builds tolerance in a kind of annoying way; it prevents me from napping or sleeping even when it no longer makes me not tired.
Interesting. I can sleep just fine on modafinil, but I still have greatly increased focus if I just choose to stay awake. Also, I've never noticed any increase in tolerance (which I get very quickly with caffeine and alcohol), even taking it every day for two weeks, although maybe that's not very long.
* not diagnosed with narcolepsy or depression already
Looking up some primary source just now: http://www.oncologypractice.com/fileadmin/content_pdf/cpn/ar...
(for some reason the UI doesn't let me reply to the reply, so here goes)
Now that I'm looking around at papers, it seems like there is evidence that it helps patients who are already depressed get some energy back.
[1] http://www.ncbi.nlm.nih.gov/pubmed/20164566
[2] http://www.sciencedirect.com/science/article/pii/S0301008204...
For example, Noopept, the di-peptide form of the nootropic piracetam, has been shown to lower levels of amyloid plaques via "hydrophobic interactions with toxic amyloid oligomers, [which] prompts their rapid sequestration into larger fibrillar amyloid aggregates." In the linked study, researchers concluded that the "mitigating effect of noopept against amyloid oligomeric cytotoxicity may offer additional benefits to the already well-established therapeutic functions of this new pharmaceutical."[1]
The abilities of substances like this to protect the brain as we age, are examples of why we need to move major parts of the medical field to focus on preventative and rejuvenating medicine, instead of just treatment for the final symptoms of a disease that has been in progress for decades...
Background info:
This is a process of what is now called the glymphatic system. The scientest quoted in the article (M. Nedergaard), previously coined the term "glymphatic" in her paper[2] "The Garbage Truck." She was a follow-on author on the paper referenced in the NPR story, "Sleep Drives Metabolite Clearance from the Adult Brain." It is a pretty interesting paper and I have a full-text copy available in my private research vault [3].
[1] http://nootroo.com/researchvault/neuroprotective-and-nootrop...
[2] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3749839/pdf/nihm...
[3] http://nootroo.com/researchvault/sleep-drives-metabolite-cle...
http://healthysleep.med.harvard.edu/healthy/matters/benefits...
http://www.psywww.com/intropsych/ch06_memory/studying_before...
I'd wager it's more like keeping an engine idling because it's less expensive/dangerous than turning it all the way off and restarting it.
"Although the average adult human brain weighs about 1.4 kilograms, only 2 percent of total body weight, it demands 20 percent of our resting metabolic rate (RMR)—the total amount of energy our bodies expend in one very lazy day of no activity."
http://www.scientificamerican.com/article/thinking-hard-calo...
1. What makes you so sure you learn nothing during sleep? All the articles I've read about sleep's role in learning have indicated that it helps us process what we pick up during the day.
2. Why is 'progress' so important? Progress towards what? What are we chasing after?
Whilst I realise you were only questioning sleep from the point of view of its utility, for me utility alone kind of misses the point. For me the rituals around sleep are some of the best parts of daily life. I love drifting off to sleep, I love dreaming (when I'm lucky enough to remember it at least), I love waking up without any great urgency, slowly coming to my senses, wrapped in the warmth of a comfortable bed. Whilst I appreciate it wasn't your intention, I dislike the notion that our time must be spent on making ourselves better people, if we aren't causing great harm isn't enjoying what we do reason enough to do it?
It's too bad our economic society doesn't value sleep? Never understood having to arrive at most jobs before 10 a.m. I've had so many jobs that want employees there the job site at 7 a.m.? I show up, but I'm not truly working until afer 10 a.m., and I'm not the only one?
Then again--I have honestly never been a morning person.
On the other hand people sleep better in the dark so if your start time implies you're going to bed when it's light out it could cause problems. Unless you use a prosthetic night (curtains).
I don't understand how people manage this. I fall asleep in less than 5 minutes if I lie down while the Sun is up in the morning, and stay solidly asleep until an appropriate number of hours have passed. Going to bed in the dark, I can toss and turn for anywhere from 30-120 minutes before finally dozing off.
Night owlism is real, and it's seriously debilitating to be required to conform to working a 9-5/10-6 job. It's Friday night, so I get to live my weekend hours. It's 2:30am now, and I'll be up another few hours. Whenever I am on vacation, or between jobs, I instantly swap to a nocturnal schedule. It is extremely painful to have to work during the day, to the point where I burn out after 12-18 months at a job. For the first time in a decade, I've almost made it 2 years at a single employer. That time is running out. I need a reversion back to my normal hours for a while. :(
"It's probably not possible for the brain to both clean itself and at the same time [be] aware of the surroundings and talk and move and so on,"
So it would be the equivalent of a forced sleep, since you can't be conscious at the same time, but that might still be useful.
Think of, for instance, the "language" areas (Broca's area and Wernicke's area). (The following over-simplified explanation assumes typical right-hand dominant individuals for the sake of brevity.) If you inactivate that area in the left hemisphere (using drugs or transcranial magnetic stimulation), you'll lose "language" processing of data that occurs around 1 Hz (in English, this corresponds to individual words, phonemes; in tonal languages, this includes tones of lexical significance). If you inactivate that area in the right hemisphere instead, you'll lose "language" processing of data that occurs an order of magnitude slower than that (in most languages, this corresponds to pitch and volume changes over the level of the sentence, and can convey prosody information such as speaker intent as well as speaker identity).
Due to specializations like this, hemispherectomies are not performed later in life. You would get symptoms similar to stroke patients. But for all areas, not just language.
In adults (or even adolescents) though, not as much luck.
In the case of hemispherectomies on Rasmussen's patients, you can analogize it as: people are dual-core by default. If you remove one of the cores early enough in life (like <5 yrs old), you can re-route the wiring so that processing can done by one of the cores, and still be pretty much normal. But whatever subtle thing is lost when if we don't do parallel processing like we usually do -- that things is pretty subtle to test for as well.
https://en.wikipedia.org/wiki/Cerebellar_hypoplasia#Signs_an...
There have been quite a bit of research on people with severed brain stems, where the brain halves effectively are cut off from each other and limited to communicating through external senses. In those situations the brain halves are actually exceedingly good at trying to obscure that anything is wrong by making inferences of actions carried out by one brain half that the other one could not possibly have knowledge of.
The bigger problem is that because the brain halves control different parts of the body, we'd likely lose a lot of our physical function.
(Not sure precisely how different that is from the experience of most office workers ;) ).
The fact that sleep still exists seems to suggest that this is hard and involves some nasty tradeoffs between the "dishwasher mode" and more operational neurological states. It's also likely that more than just this occurs, and that sleep is used to take care of a whole laundry list of housekeeping operations.
We have "pausing GC"... heh.
Except prior to artificial light sources, you would still be forced to stay sheltered or spend your time huddled up with weapons at the ready.
> and you get twice as much working time per day.
Until our work consisted of something other than hunting and gathering this would likely not have been all that much of a benefit.
On evolutionary timescales it would seem most of our evolution has happened in conditions where we were severely constrained with respect to what we could safely do during the night anyway, and so there'd be relatively little benefit to working around whatever the problems of avoiding sleep are.
I don't doubt that cutting sleep will pose all kinds of challenges we're not even aware of yet, though.
:)
The evolutionary argument is nice but maybe we're just stuck in an old 'branch' local minima. Think of axolotl limb regeneration. We only have partial regeneration but somehow nature felt it was more efficient not to regenerate full limbs and try to survive crippled. Long sleep may have been necessary, but maybe that's not the case anymore.
Curcumin and Alzheimer’s disease. Our group has tested curcumin in several models and found that it not only reduces oxidative damage and inflammation (as expected), but also reduces amyloid accumulation and synaptic marker loss while promoting both amyloid phagocytosis and clearance. In in vitro studies, we found curcumin worked to prevent synaptic marker and cognitive deficits caused by amyloid peptide infusion and abeta oligomer toxicity. Our work on curcumin and AD is discussed in detail in our publications
its important to note that it is only the Longvida formulation of Curcumin which effect because it crosses the blood-brain barrier, although other types seem beneficial for other conditions.
I'm skeptical of the brand in particular, not in the sense that it's bio-available, but their claim that only their brand crosses the blood-brain barrier[1][2].
[0] a lot of sites mention this in passing, but here's a study that shows 7 days of supplementation crosses the blood-brain barrier, at least in mice: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2781139/
[1] http://news.vanderbilt.edu/2015/01/curcumin%E2%80%99s-abilit...
[2] http://www.petesplacenutritionalsupplementblog.com/2014/09/c...
The clearance of beta-amyloid, etc. is largely linked to the state of sleeping that would be tough to isolate without inducing sleeping itself.
If it were possible to induce this "dishwasher-like" surge of cerebrospinal fluid in the brain during waking hours, would we be able to live off of significantly less (or no) sleep?
I'm not saying that it's necessarily a good idea, but it would have a plethora of practical applications -- pilots, truckers, etc. would be able to stay awake in a healthful way, rather than by ingesting stimulants.
I've been interested in the science of sleep for a while -- I wrote a side project, http://sleepyti.me, that actually gets quite a bit of traffic -- but neuroscience is mostly lost on me.