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Innovation Blues

Caffeine: A User's Guide to Getting Optimally Wired - Developing Intelligence - 0 views

scienceblogs.com/...optimally-wired-a-caffeine-use

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shared by Innovation Blues on 10 Aug 12 - No Cached
  • Caffeine: A User’s Guide to Getting Optimally Wired
  • Caffeine is the most widely used stimulant in the world, but few use it to maximal advantage. Get optimally wired with these tips.
  • 1) Consume in small, frequent amounts. Between 20-200mg per hour may be an optimal dose for cognitive function. Caffeine crosses the blood-brain barrier quickly (owing to its lipid solubility) although it can take up to 45 minutes for full ingestion through the gastro-intestinal tract. Under normal conditions, this remains stable for around 1 hour before gradually clearing in the following 3-4 hours (depending on a variety of factors). A landmark 2004 study showed that small hourly doses of caffeine (.3mg per kg of body weight [approx 20 mg per hour; thanks digg!]) can support extended wakefulness, potentially by counteracting the homeostatic sleep pressure, which builds slowly across the day and acts preferentially on the prefrontal cortex (an area of the brain thought responsible for executive and “higher” cognitive functions).
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  • 2) Play to your cognitive strengths while wired. Caffeine may increase the speed with which you work, may decrease attentional lapses, and may even benefit recall – but is less likely to benefit more complex cognitive functions, and may even hurt others. Plan accordingly (and preferably prior to consuming caffeine!)
  • Recall from memory may be improved by caffeine (here and here), possibly due to enhancements in memory encoding rather than retrieval per se. Another study shows caffeine can actually impair estimates of “memory scanning” speed (in the Sternberg paradigm), so the failure of many studies to find recall-related effects of caffeine may reflect a speed-accuracy tradeoff at the time of retrieval.
  • 3) Play to caffeine’s strengths. Caffeine’s effects can be maximized or minimized depending on what else is in your system at the time. The beneficial effects of caffeine may be most pronounced in conjunction with sugar. For example, one factor analytic study has shown caffeine-glucose cocktails provide benefits to cognition not seen with either alone.
  • Withdrawal symptoms can onset within 12 to 24 hours of caffeine consumption and last between 2 and 9 days.
  • Caffeine’s effects might be masked by green tea extract, Kava Kava or St. John’s Wort – all of which contain theanine and are associated with subjective feelings of relaxation – but other preliminary evidence indicates the opposite effect: theanine might actually potentiate the benefits of caffeine on some tasks (reported in longer format here).
  • Similarly, nicotine may speed the metabolism of caffeine.
  • 4) Know when to stop – and when to start again. Although you may not grow strongly tolerant to caffeine, you can become dependent on it and suffer withdrawal symptoms. Balance these concerns with the cognitive and health benefits associated with caffeine consumption – and appropriately timed resumption.
  • Long-term ingestion of large quantities of caffeine (by way of coffee) is associated with a variety of health benefits – not only cognitive enhancements but also reduction in risk for type 2 diabetes (c.f.), Alzheimer’s and Parkinson’s . These beneficial effects may be related to the neuroprotective role of adenosine.
  • some studies show grapefruit juice might keep caffeine levels in the bloodstream high for longer, though others have found no such effect
  • In addition, there are well-established cognitive effects where recall is best when it matches the context of encoding – so if you’re caffeinated when you study for the test, you better be caffeinated when you take it.
  • 5) Finding good sources of caffeine Despite the huge variety of sources of caffeine – including caffeinated soap, candy, and of course chocolate – the optimal use of caffeine is likely to involve small, hourly doses along with some cardioprotective agent. Given the high solubility of caffeine, absorption time should not be an issue (but if for some reason it is, try gum). Otherwise, why not enjoy a cup of green tea (coffee-flavored, if you must), as the Chinese have for nearly 5000 years? It’s hard to come by a better longitudinal study than that.
Innovation Blues

What Caffeine Actually Does to Your Brain - 0 views

lifehacker.com/...ne-actually-does-to-your-brain

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shared by Innovation Blues on 10 Aug 12 - Cached
  • affeine is one seriously misunderstood substance. It's not a simple upper, and it works differently on different people with different tolerances—even in different menstrual cycles. But you can make it work better for you.
  • Luckily, one intrepid reader and writer has actually done that reading, and weighed that evidence, and put together a highly readable treatise on the subject. Buzz: The Science and Lore of Alcohol and Caffeine, by Stephen R. Braun, is well worth the short 224-page read. It was released in 1997, but remains the most accessible treatise on what is and isn't understood about what caffeine and alcohol do to the brain.
  • Caffeine Doesn't Actually Get You Wired Right off the bat, it's worth stating again: the human brain, and caffeine, are nowhere near totally understood and easily explained by modern science. That said, there is a consensus on how a compound found all over nature, caffeine, affects the mind.
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  • Normally, when adenosine levels reach a certain point in your brain and spinal cord, your body will start nudging you toward sleep, or at least taking it easy. There are actually a few different adenosine receptors throughout the body, but the one caffeine seems to interact with most directly is the A1 receptor.
  • it functions as a supremely talented adenosine impersonator. It heads right for the adenosine receptors in your system and, because of its similarities to adenosine, it's accepted by your body as the real thing and gets into the receptors.
  • caffeine actually binds to those receptors in efficient fashion, but doesn't activate them—they're plugged up by caffeine's unique shape and chemical makeup. With those receptors blocked, the brain's own stimulants, dopamine and glutamate, can do their work more freely—"Like taking the chaperones out of a high school dance,"
  • caffeine very clearly doesn't press the "gas" on your brain, and that it only blocks a "primary" brake. There are other compounds and receptors that have an effect on what your energy levels feel like—GABA, for example—but caffeine is a crude way of preventing your brain from bringing things to a halt. "You can," Braun writes, "get wired only to the extent that your natural excitatory neurotransmitters support it." In other words, you can't use caffeine to completely wipe out an entire week's worth of very late nights of studying, but you can use it to make yourself feel less bogged down by sleepy feelings in the morning.
  • What's important to take away is that caffeine is not as simple in effect as a direct stimulant, such as amphet
  • amines or cocaine; its effect on your alertness is far more subtle.
  • The general consensus on caffeine studies shows that it can enhance work output, but mainly in certain types of work. For tired people who are doing work that's relatively straightforward, that doesn't require lots of subtle or abstract thinking, coffee has been shown to help increase output and quality. Caffeine has also been seen to improve memory creation and retention when it comes to "declarative memory," the kind students use to remember lists or answers to exam questions.
  • The effectiveness of caffeine varies significantly from person to person, due to genetics and other factors in play. The average half-life of caffeine—that is, how long it takes for half of an ingested dose to wear off—is about five to six hours in a human body. Women taking oral birth control require about twice as long to process caffeine. Women between the ovulation and beginning of menstruation see a similar, if less severe, extended half-life. For regular smokers, caffeine takes half as long to process—which, in some ways, explains why smokers often drink more coffee and feel more agitated and anxious, because they're unaware of how their bodies work without cigarettes.
  • regular caffeine use has also been shown to decrease receptors for norepinephrine, a hormone akin to adrenaline, along with serotonin, a mood enhancer. At the same time, your body can see a 65 percent increase in receptors for GABA, a compound that does many things, including regulate muscle tone and neuron firing. Some studies have also seen changes in different adenosine receptors when caffeine becomes a regular thing.
  • A 1995 study suggests that humans become tolerant to their daily dose of caffeine—whether a single soda or a serious espresso habit—somewhere between a week and 12 days. And that tolerance is pretty strong.
  • You start to feel caffeine withdrawal very quickly, anywhere from 12 to 24 hours after your last use. That's a big part of why that first cup or can in the morning is so important—it's staving off the early effects of withdrawal. The reasons for the withdrawal are the same as with any substance dependency: your brain was used to operating one way with caffeine, and now it's suddenly working under completely different circumstances, but all those receptor changes are still in place. Headaches are the nearly universal effect of cutting off caffeine, but depression, fatigue, lethargy, irritability, nausea, and vomiting can be part of your cut-off, too, along with more specific issues, like eye muscle spasms. Generally, though, you'll be over it in around 10 days—again, depending on your own physiology and other factors.
  • Beyond the equivalent of four cups of coffee in your system at once, caffeine isn't giving you much more boost—in fact, at around the ten-cup level, you're probably less alert than non-drinkers.
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