Tox Tuesday: Caffeine

It could be from coffee, tea, soda, energy drinks, jelly beans, chocolate, pills or even in powder form, but the fact of the matter is, there are some days I just need my caffeine. I may have pulled a couple all-nighters in my college years drinking cup after cup of tea to finish my final paper. I even have friends, family members and coworkers who drink several cups of coffee per day just to stay functional. Caffeine is a saving grace in that way—but there’s so much more to this substance than just the wake-me-up we could all use now and again.

Caffeine can be found in seeds, leaves and in fruit of plants in varying levels. In its natural form, it acts as a pesticide for some insects, while enhancing the reward memory of pollinators—but more on that later.

First, we’ll discuss the impacts of the crystalline xanthine alkaloid in humans.

Odorless and bitter in taste, caffeine’s effects extend beyond increased mental alertness and central nervous system stimulation. It can also reduce fine motor coordination and cause insomnia, headaches, nervousness and dizziness in moderate doses. In some cases, especially in large doses, caffeine can be lethal.

Caffeine never tasted so good.

Caffeine never tasted so good.

Caffeine can also have different effects in males and females. After puberty, males are more likely to experience greater heart-rate and blood-pressure changes compared to females. Before puberty, these changes can be seen as well, even in low doses of caffeine. In females, caffeine effects can be different across phases of the menstrual cycle. Decreases in heart rate were greater in the mid-follicular phase, and blood pressure increases were greater in the mid-luteal phase of the menstrual cycle.  Ladies, if you’re on birth control pills, you metabolize caffeine one-third slower than women who aren’t on the pill. In general, women metabolize it faster than men.

On opposite ends of the spectrum: Smokers process caffeine twice as quickly as non-smokers, and Asians, overall, process it more slowly than other races.

Regardless if you’re male or female, however, caffeine can make you drink more alcohol. In a study from the Center for Research on Aging, Health and Well-Being at Australian National University, it was found that those who combined both alcohol and caffeine (in the form of energy drinks) reported a heightened urge to continue to consume alcohol versus their counterparts not consuming caffeine.

Other studies are being reported that cite caffeine consumption results in lower risk of cardiovascular disease and diabetes, minimized age-related cognitive decline and reduced risk of cancer development and Parkinson’s disease.

And despite the relative safety of caffeine—I haven’t encountered a problem, apart from some sleepless nights after having a caffeinated cup of tea too soon before bed—the Drug Abuse Warning Network is reporting a tenfold increase in emergency room visits due to caffeine-containing energy drinks been 2005 and 2009.

The U.S. Substance Abuse and Mental Health Services Administration has similar statistics: emergency room visits from energy drinks rose 36% from 2010 to 2011.

“People often don’t understand the potential risks of these beverages,” Bruce A. Goldberger, director of forensic toxicology at the University of Florida, said.

Part of the problem may be that it is difficult for scientists to establish a “toxic dose.” Some scientists have established it around 10 grams, but the toxicity levels can change depending on how the person processes caffeine. Ten grams is roughly the equivalent of 75 eight-ounce cups of coffee.

Health Canada has recently set a new standard, saying that caffeine consumption at or below 400 milligrams per day (about three eight-ounce cups of coffee) is safe for healthy adults. The organization also established a limit of 2.5 mg per kg body weight per day for children. For an average 10-year-old, that is about two 12-ounce cans of Coca-Cola.

Back to the root of where it all begins, in plants, pollinators are finding effects from naturally-occurring caffeine as well. Just as it helps humans be more alert, caffeine can help improve a honeybee’s memory.

Scientists are studying the effect of caffeine on bees’ brains to better understand how landscapes could be better managed, as well as how the drug affects human brains and behavior.

For more information on Neogen’s kits for the detection of caffeine, as well as other drug detection products, click here.

Comments are closed.