Caffeine Withdrawal

Bad news, coffee drinkers: your morning joe may not be having the wonderful effects you think it does. And if you're a heavy consumer, it gets even worse. A recent paper in Neuropsychopharmacology looks at the effects of caffeine (approximately equivalent to 2 cups in the morning) on non-, moderate- or high-caffeine consumers. From the abstract:

With frequent consumption, substantial tolerance develops to the anxiogenic effect of caffeine, even in genetically susceptible individuals, but no net benefit for alertness is gained, as caffeine abstinence reduces alertness and consumption merely returns it to baseline.

The data showed that after a night of abstinence - participants were instructed to consume no caffeine after 7pm the previous evening - heavy caffeine consumers (on average ~350mg per day) showed no benefit to alertness from caffeine, but rather a precipitous decline in alertness when given placebo, compared to light- or non-consumers. They also reported a large increase in headaches when deprived of caffeine. How bad were they? Almost 4% of the group withdrew from the study due to headaches and feeling sick. This all suggests that rather than actually improving alertness in heavy consumers, the morning coffee ritual merely mitigates withdrawal effects, returning them to 'baseline'.

Surprisingly, in low- or non-consumers caffeine showed no difference in alertness, compared to placebo, but did result in increased anxiety and slight increase in headaches. The authors suggest this is due to discrepancies between this and earlier studies. Previous research on the effects of caffeine on alertness seems to have relied mostly on self-reported caffeine consumption. In this case, reporting was validated and compliance enforced based on saliva levels of caffeine and its metabolites.

The authors also identified a genetic component involved in modulating the anxiety effects of caffeine. A SNP in the adenosine A_2a gene (ADORA2A) "showed greater susceptibility to caffeine-induced anxiety", and while people of that particular genotype habitually consumed more caffeine on average, the effects on anxiety were only observed in the low end consumers. Moderate to high consumers seemed to be tolerized to the effects.

It's also worth pointing out that 90% of the population from which participants were drawn (adults living in Bristol, UK) fall into the moderate to high caffeine consumption category (>40mg/day). If that's representative of western society, then most of us are sub-optimal without our morning hit. It also explains the widespread notion that coffee improves alertness: it does, but only because we're suffering without it.

Why Does Coffee Make You Pee?

How diuretic is caffeine? Does your morning coffee make you pee more that a decaf would? What about green tea or cola? Scicurious has the answers in her latest Friday Weird Science.

Coffee and cancer

I recently had an armchair expert tell me that french press style coffee vs a filtered coffee preparation method increases your risk of cancer. [Don't confuse french press coffee for the biological apparatus]. This person was foggy on the details but indeed got rid of their Bodum(tm). Personally I find coffee from a french press tastes superior, but then again, I'd drink it off a dog some mornings. Some googling revealled one source of the idea that unfiltered coffee increases your risk of cancer the source they cite is an article that shows increased homocysteine levels in drinkers of unfiltered coffee vs NO COFFEE. (no coffee?!?!) Homocysteine itself is not directly derived from your diet, however, high levels in the blood are indicators for high risk of heart attack and stroke, and possibly cancer. The thought was that filtering coffee removed what the authors assumed was causing the rise in homocysteine levels. Turns out filtering coffee doesn't change the fact that drinking coffee raises homocysteine levels.
To me this is a good example of something I see often, that is, cancer research NOT serving the public who funds it. If this is the crappy way that the public is informed about cancer research I'm surprised it still is funded. Someone gets rid of their french press because their concerns for their health based on the mainstream medias reporting of an incorrect assumption in the literature. What is also strange is that the damage is done. I think I would have a hard time convincing this person that their french press coffee is no worse for them.
Also I think there is a leap of logic here that I have heard is similar to the leap in logic made for the statin class of drugs. That is that since higher homocysteine levels correlate with higher risk of cancer (let's assume the one article I found linking the two is correct), then homocysteine is a cause of cancer. An indicator is not necessarily the cause but is merely associated with increased risk.
Also it may be that coffee raises cancer causing homocysteine levels by an appriciable amount, however, other factors associated with coffee drinking may result in an overall reduction in cancer incidence. So again even if homocysteine causes cancer, coffee may not.
Of course, perhaps coffee has so taken over control of my thought processes that I am in denial.

State-of-the-Art Geeky Coffee

The coffee-maker pictured above is known as a Japanese siphon bar (see the NY Times website to see a slide-show of the thing in action). It is the only one of its kind in the US, imported for a mere $20,000. Eleven dollar globes of the non-espresso coffee product are apparently all the rage on the San Fransisco hipster-blogger-academe coffee-shop scene. The Times recently reported on this new trend in high-end brewed coffee making. The siphon bar is found at the Blue Bottle Coffee Company. Owner James Freeman explains the concept:

“Does coffee brewed from single-origin beans in a siphon or a Clover taste more yummy than, say, Folgers from a percolator? I believe it does. But it would be hubris to suggest that we’re making better coffee than anyone ever has. My feeling is, there are already enough places where you can get a cinnamon latte and a muffin wrapped in plastic. Why would I want to build another one of those?”

Supposedly this thing makes the greatest cup of coffee known to (wo)man. No less than Starbucks has bought the rights to similar technology (the mystical "Clover"). I'll admit, my curiosity has been aroused. But I'm sure as hell not going to pay that kind of cash for a taste (not to mention the plane ticket). So I fired up the YouTube and did a little commercial espionage (see video clip and watch the brewing process in action). Turns out these guys are a bunch of scientist wannabes! I figure it'd be pretty easy to rig one up with a bunsen burner, a couple of flasks, a Buchner funnel and a vacuum line. All easily found within your standard biomedical research lab...except for the Yo-Yo stunt man...