Studies Show This Ingredient Combo Boosts Productivity

Jenn Stewart

While caffeine is one part of the productivity combo, there’s more. Over the past decade, the National Institutes of Health (NIH) has shown in numerous studies that there’s a better solution.

© Anna Tarazevich

At exactly 2:47pm, my productivity plummets
hard. The work day is only half done and any hope of staying alert and focused has flown out the window.

Most of us in this situation would drag ourselves over to the coffee maker and brew up another cup of productivity in the form of caffeine. Yum.

While caffeine is one part of the productivity combo, there’s more. Over the past decade, the National Institutes of Health (NIH) has shown in numerous studies that there’s a better solution.

What if you could power through the afternoon slump with all the energy and focus you need… without a bad case of the coffee jitters or crash?

Caffeine + L-Theanine

This is the winning combo where productivity meets focus. Caffeine and L-theanine are the elements that come together to create something awesome: a prolonged source of healthy energy. 

As a psychoactive substance (yes, a drug), caffeine stimulates the brain and central nervous system. 

But caffeine doesn’t erase the tiredness. What makes us feel tired is the adenosine neurotransmitter. The more adenosine binds to receptors in your brain, the sleepier you feel. Caffeine simply blocks those receptors, so adenosine cannot bind and create those *yawn* sleepy feelings. But caffeine doesn’t stop adenosine from building up over the day.

When the effects of caffeine suddenly wear off and those receptors are open again, that flood of adenosine creates what’s commonly known as the caffeine crash.

Enter L-theanine, which has a whole host of benefits for your brain. A 2019 study found:

“Stress-related symptom (i.e., depression, anxiety-trait, and sleep) scores decreased and cognitive function (i.e., verbal fluency and executive function) scores improved after four weeks of L-theanine administration.”

Graph showing improvement in depression, anxiety, and sleep quality, when using L-Theanine compared to a placebo. Source:

L-theanine is an amino acid (remember those from high school biology?) that’s found in certain plants, just like caffeine. It increases levels of dopamine, the feel-good neurotransmitter, and serotonin, the mood-stabilizing neurotransmitter, to help you feel good… and focused. 

And L-theanine isn’t one of those hard-to-find, mythical ingredients. It’s found naturally in tea, and anyone can consume it. Even Taylor Swift told Elle she takes L-theanine supplements for stress and anxiety.

More importantly, L-theanine does not make you feel drowsy and the calming effects of this clean energy can last 8 to 10 hours. So, when we combine the energizing effects of caffeine with the stabilizing effects of L-theanine, you get the much-needed productivity boost and the calm focus to channel energy into work (or Candy Crush).

BONUS: the long-lasting calming effects of L-theanine also work on that caffeine crash. Instead of diving off the edge, L-theanine prolongs calmness and focus as you drift to healthy energy levels.

Productivity backed by science

The combination of caffeine and L-theanine has been studied for over a decade now, with numerous significant publications from the NIH. To save you one long afternoon scrolling through the jargon, here’s what you need to know.

Boost Energy

Many studies are confirming that caffeine and L-theanine, separately and especially together, boost energy. But there’s one study that just sums it up so well:

“the combination also led to faster simple reaction time, faster numeric working memory reaction time and improved sentence verification accuracy”

Your boosted energy will also improve how fast you remember things, correct things, react to things, and your accuracy overall. That’s the kind of performance-boosting energy needed for an afternoon of solid productivity.

Enhance Alertness

Alertness is an important part of productivity… but measuring alertness, or lack of it, isn’t the easiest thing to do. Most studies are using self-reported data to determine how the caffeine + L-theanine combo affects alertness, which isn’t overly accurate.

Still, the results from this early 2008 study found:

“’Headache’ and ‘tired’ ratings were reduced and ‘alert’ ratings increased.”

Then, two years later, another randomized controlled study discovered:

“The combination of moderate levels of L-theanine and caffeine significantly improved accuracy during task switching and self-reported alertness (both P < 0.01) and reduced self-reported tiredness (P < 0.05).”

There seems to be a trend forming, and the good news is that you can test and measure your own alertness improvements with products like Zest Tea, which were built to replicate these results.

Improve Accuracy

A little improved accuracy will go a long way, but accuracy is often thrown out the window to make room for that BIG caffeine energy buzz. With L-theanine, it’s a different story, as this 2008 study discovered.

“The L-theanine and caffeine combination improved both speed and accuracy of performance of the attention-switching task at 60 min, and reduced susceptibility to distracting information in the memory task at both 60 min and 90 min.

The test subjects were faster and more accurate when quickly changing from one task to another. Similar to not losing 30 minutes on Facebook between checking emails.

The study concludes:

“L-theanine and caffeine in combination are beneficial for improving performance on cognitively demanding tasks.”

Reduce Caffeine Jitters

According to a double-blind, placebo-controlled study:

“Combining L-theanine with caffeine, at levels and ratios equivalent to one to two cups of tea, eliminated the vasoconstrictive effect and behavioural effects of caffeine.”

Tea: 1

Coffee: 0

Unlike coffee, tea can provide some of the caffeine energy you need… without the “behavioral side effects” like the jitters, leg bouncing, word vomit, and come-down shakes. The L-theanine caffeine combo can also prevent the high blood pressure your doctor has been on about, by eliminating the vasoconstrictive effects.

Manage ADHD

Finally, there’s attention deficit hyperactivity disorder (ADHD) and the effects of caffeine and L-theanine on this condition.

A 2019 study aimed to discover if caffeine + L-theanine improved sustained attention in those with ADHD in the same way it does for adults. The results were promising.

“While L-theanine alone and caffeine alone seem to increase impulsivity, the combination seems to decrease (i.e., improve) impulsivity in children with ADHD.”

The study summarizes that L-theanine and caffeine improves overall cognitive performance in children with ADHD. A recent study from August 2020 has confirmed this: 

“L-theanine, caffeine and particularly their combination have the potential to be translated to manage cognitive deficits associated with ADHD.”

Increasing focus and decreasing mind-wandering will be useful for most but could be life-changing for some.

Thanks to the promising results of these leading NIH studies, more resources are being poured into finding out how L-theanine and caffeine can take productivity to the next level.

Tea: a one-stop productivity shop?

Tea, which naturally contains both L-theanine and caffeine, has been boosting the cognitive function of our ancestors for centuries (whether they realized it or not).

The problem is, while tea doesn’t have enough caffeine compared to your standard cuppa Joe, coffee doesn’t have any L-theanine. You’d have to drink about 3 cups of tea to get the effects described in the Caffeine + L-theanine studies.

That’s a lot of tea, and a lot of toilet breaks. Not so good for productivity!

And this is where enterprising businesses are harnessing the productivity power of L-theanine and caffeine from tea, without the gallons of water.

Business boosting productivity

The productivity market is energetic right now! After dragging ourselves through 2020, we’re all looking to get back on our feet, right?

Businesses are all too happy to help (for a price).

L-theanine supplements are hugely popular and Generally Recognized as Safe (GRAS) by the FDA, in doses up to 250mg. But this adds yet another pill to your mountain of multivitamins. Caffeine is still going strong too, from energy drinks to highly potent cold brew.

But the real ingenuity is coming from those businesses that are putting the two together. Zest Tea, founded by James Fayal, creates high caffeine tea to provide your clean energy buzz in a format that tastes good.

“The idea for Zest Tea came to me while working long hours as a financial analyst. I was an avid tea drinker, but found myself switching to whatever sludge for coffee we had at the office or a heavily sweetened energy drink from the local convenience store. Eventually, I got tired of making the compromise and developed Zest Tea as a healthier and tastier energy alternative. We use the combination of caffeine and L-theanine to help provide a more prolonged alertness without a jittery pop or crash.”

Yes, this guy created a productivity solution with caffeine/L-theanine that’s natural, full of energy, and tastes delicious. Definitely a winning best tea for energy. 

Millions of customers, especially those in the medical industries who were already overworked  before a pandemic landed on our doorstep, have wasted no time jumping on the caffeine tea train with Zest Tea. 

Replacing coffee with highly caffeinated tea that uses natural tea extract to boost the caffeine and L-theanine gives you all those impressive benefits listed above. Thanks, science.

Is this the end of procrastination?

Probably not. But getting more done with a sustainable, natural energy buzz is definitely in reach with highly caffeinated tea.

There’s a bright future for caffeine and L-theanine. The potential of these ingredients is sparking more studies every year to show how our cognitive function can be improved too.

2021 looks like good news for productivity and focus!

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