|Caffeine and adenosine are like brothers from another mother.|
Adenosine accumulates in our brain the longer we stay awake, binding to its receptors to induce that sleepy feeling we all get after a long day. It is the body’s way of signaling to the brain that it has had enough and needs to shut down for a while. If you disagree with your body, the ingestion of caffeine can help. Due to their structural similarity, caffeine competes with adenosine for binding to adenosine receptors; however, adenosine receptors do not execute the signal to shut down when bound to caffeine. In other words, the body is trying to throw a pass to sleep but caffeine blocks the receiver.
But that’s not all. Caffeine also ramps up adrenaline production, which increases your heart and breathing rates, and primes your brain and muscles for action. You feel a boost from coffee because the caffeine blocks the signal to sleep and fools your body into thinking it is under attack.
How much coffee can people safely consume? According to the FDA, 400 mg (4 cups of brewed coffee) per day appears to be safe for most healthy adults. While it is estimated to take about 140 cups (8 oz size) of coffee to kill, you can get there a lot quicker with pure caffeine powder. A single tablespoon can be lethal, prompting the FDA to issue this warning to consumers.
But there is a creature on Earth that can tolerate much, much more. In fact, it eats coffee beans for breakfast. And lunch. And dinner. And everything in-between. Amazingly, the coffee berry borer eats nothing but coffee beans!
|The coffee berry borer is a small but devastating beetle that lays waste to coffee crops. It subsists solely on coffee, capable of drinking any Starbucks junkie under the table.|
Scientists have recently discovered how the coffee berry pest can tolerate toxic levels of caffeine. Do they possess a special gene that can detoxify caffeine? Do they have receptors that don’t bind caffeine? No…evidently, the answer does not lie in the genome of the beetle, but in its gut.
To further test this hypothesis, researchers gave the beetles antibiotics to deplete their intestinal microbiome. Beetles without their gut bacteria lost the ability to break down caffeine. When fed some P. fulva before their coffee bean diet, the beetles excreted no caffeine, indicating that they were able to detoxify it once again.
|Assuming no adverse effects, ingestion of P. fulva might help humans break down caffeine. A better alternative to decaf?|
From an evolutionary perspective, the study serves as an example of how organisms can adapt to a new niche without genetic modification. By acquiring specific types of bacterial symbionts, the coffee berry borer is uniquely able to live off nothing but coffee.
In the video below, you can learn more about this research and similar studies being performed at Lawrence Berkeley National Laboratory:
Contributed by: Bill SullivanFollow Bill on Twitter.
See the news release at ScienceDaily.Ceja-Navarro, J., Vega, F., Karaoz, U., Hao, Z., Jenkins, S., Lim, H., Kosina, P., Infante, F., Northen, T., & Brodie, E. (2015). Gut microbiota mediate caffeine detoxification in the primary insect pest of coffee Nature Communications, 6 DOI: 10.1038/ncomms8618