Why Doesn’t Tea Make Me Wired?

The Dreaded Lunchtime Seminar

It is 12:05 and the coffee and cookies still have not arrived. 12:10. No coffee in sight. 12:15. To my dismay, the speaker is going to begin! No caffeine to keep me awake. No cookies to make up for the lunch I forgot to bring.

The lights go out, the projector goes on, and this week’s speaker begins a fifty-minute drone. Picture after picture of indecipherable graphs. Endless hesitations and false starts. Blank stares—on the part of the speaker and the audience—at irrelevant content; puzzlement as to why that image is in this particular spot. AARGH! Why has the clock stopped and why is this room so hot? And why oh why didn’t the coffee get here in time?

Because caffeine can spell the difference—between counting ceiling tiles and speaker “um”s in a desperate attempt to remain conscious . . . and actually being alert enough to attend to a mind-numbing lecture.

Because caffeine can do wonderful things for the sleep-deprived or the disengaged.

And I’m talking about the jolt we get from coffee. Few are reaching for the teapot here.

So What’s the Difference? Why Not the Teapot?

Because there is less caffeine in brewed tea than in brewed coffee, right?

That’s true, but it isn’t the entire story.

The plants that we process for coffee, tea, chocolate, and mate all contain methylxanthines—which have real health benefits (see my last post), impart flavor (that bitterness? blame some of that on the caffeine), and are used in medicines.

chart

Because they easily cross the blood-brain barrier, methylxanthines directly affect our bodies. However, the various xanthines work differently, in ways that are not always well understood.

For example, we all know that eating chocolate will not hit like a shot of espresso, due presumably to its lower caffeine content—but the exact reason remains under study, with scientists looking at such things as plasma concentration, half life, and targets for specific xanthines. And while caffeine, theophylline, and theobromine each work differently with our brain’s adenosine receptors—with caffeine keeping us awake and theobromine possibly boosting sleep duration—there is also some indication that the caffeine and theobromine in cacao work together as a psychostimulant. Well that muddies things up.

Still, we know that if we really need to pay attention and not drift off, chocolate isn’t going to do it, but mate might and coffee probably will. And tea?

The Secret Ingredient

Brewed tea does have caffeine. Less than brewed coffee, but caffeine is caffeine. It’s that extra component, the theanine—or L-theanine more specifically—that makes us bypass the teacup and reach for the coffee mug when we want caffeine right now!

Theanine is a unique amino acid, found in tea and the Boletus radius mushroom. Theanines comprise the bulk of tea’s amino acids, giving tea its umami flavor. Because sunlight converts these amino acids to polyphenols, tea grown in shade retains more of its theanine while that grown in sunlight has less (resulting in flavor differences).

The great thing about the L-theanine, though, is that it directly impacts the brain, significantly increasing alpha brain wave activity.

And that means?

The alpha waves are the goal of biofeedback and meditation and mindfulness—the brain waves that relax us. And, caffeine and L-theanine work synergistically to improve brain function and attention.

This is a double win: relaxation coupled with alertness!

So Why Not the Teapot?!

To truly pay attention to that tedious lecture, perhaps I should be pulling out the teapot. Alpha waves, calm alertness. Seems that would enable active listening. . . . versus being wired, ready to pounce if the speaker says “ummm” one more bleeping time!

COMING UP:  A look at what determines how much caffeine is in your cup of tea.


Sources:
–”Alpha brain waves boost creativity and reduce depression,” by C. Bergland, Psychology Today. April 17, 2015. http://www.psychologytoday.com/blog/the-athletes-way/201504/alpha-brain-waves-boost-creativey-and-reduce-depression.
–”Health benefits of methylxanthines in cacao and chocolate,” by R. Franco et al., Nutrients 5(10):4159–4173. October 2013.
–”Chemical compounds in tea,” by T. Gebely, Tea Education. 2015. http://www.worldoftea.org/category/tea-education.

The Case for Caffeine

Psychoactive Stimulant Drug!!

Wow, sounds like something I could really use at the moment. Oh, wait—I DID have a psychoactive stimulant drug. More than once actually, and it’s still morning!

Psychoactive (affects the mind) + Stimulant (increases level of physiological activity) = Caffeine

 

How Caffeine Came to Becoffee partly framed

Formally identified in 1819 by German chemist Friedrich Ferdinand Runge who called it kaffein for the compound found in Kaffee (coffee).

Actually discovered by Stone Age night owls who needed to wake up early for the morning mammoth hunt. Maybe. But we do know that our prehistoric ancestors chewed plants containing caffeine, and by around 3000 BCE, people figured out that you can get more caffeine by brewing those plants in hot water.

Caffeine stays in our bodies for quite awhile—around 4–6 hours for the average adult but far longer for those on certain medicines, pregnant women (11 hours!), and children, for instance. And no, caffeine will not stunt the growth of children or teens (though there are other problems with excessive levels of caffeine, such as energy drinks).

Reasons to Embrace Caffeine

The Well Known
Yes, those wonderful psychoactive stimulant effects that I depend on every morning!

When we ingest caffeine, it travels throughout our body. In our brain, it binds to the adenosine receptors—essentially shutting down the signal that would normally tell us that we are tired, and stimulating the central nervous system. (Adenosine is released when light dims and we should be getting sleep.)

This stimulation of the central nervous system means heightened alertness and focus and coordination. All helpful, whether hunting mammoth or a parking space.

No wonder that 90% of people ingest caffeine daily. Worldwide.

The Perhaps Less Well Known
Caffeine also reduces inflammation. It is used to treat apnea and irregular heartbeats in babies. It helps with short-term memory and mood. It is a component of many medicines, particularly those for headache (great-grandma was right—the old remedy of drinking coffee for a headache is valid).

hong cha java

Caffeine in Tea: A Bonus
And caffeine has been shown to protect against skin cancer (basal cell and squamous cell carcinoma) caused by ultraviolet radiation (sunlight, tanning lamps). When my grandmother developed skin cancer in the 1970s, few of us knew much about skin cancer and its seriousness. Today, it is a major public health problem, spurring research studies.

There are many stages in the progression of cancer, offering multiple opportunities to target treatment. Tea—with its antioxidant (due to all those polyphenols) and hence anticarcinogenic mechanisms—has great potential in preventing, slowing, or even reversing skin cancer. And indeed, ingesting green or black tea or caffeine alone has been shown to inhibit these cancers in mice.

However, decaffeinated tea had little effect.

It seems that the combination of tea with caffeine is the most effective combination. The properties of tea and caffeine may each work alone, or they may work synergistically to greater effect.

In addition, there is some laboratory evidence that tea polyphenols (by applying tea extracts topically or by drinking tea) may increase the effectiveness of sunscreen, another protector against skin cancer. As Camouse and her colleagues put it:

What is essential is to conduct more scientific studies and controlled clinical trials that would translate the promising data obtained from in vitro and animal model testing into human application.

Coming Up

cocoa powder

My next post or two will delve into some other common questions:

Is the caffeine in coffee the same as that in tea? What about chocolate and yerba mate?

 

mate

Can you know how much caffeine is in your tea, and can you do anything about it yourself? What is the connection between caffeine and flavor?

Meanwhile, enjoy a cup of tea, with or without caffeine!


Sources:
–”Caffeine,” Science of Food and Cooking, http://www.edinformatics.com/math_science/science_of_cooking/caffeine.htm.
–”Medicines in your home: Caffeine and your body,” U.S. Food and Drug Administration. Fall 2007.
–”Protective effects of tea polyphenols and caffeine,” by M. M. Camouse et al., Expert Review of Anticancer Therapy 5(6):p1060. December 2005.