How To Enjoy Sustained Energy and Alertness From Caffeine Without Jitters or Crash.

January 05, 2019

Coffee cup being broken in mid air

Have you ever felt caffeine jitters after drinking tea? No, because even though tea contains caffeine it also naturally contains L-Theanine, an amino acid that alleviates many of the negative side effects of caffeine, including jitters and crash.


What is L-Theanine?

A non-proteinic amino acid found in green tea, black tea and some mushrooms. It is available in pill and tablet form and many people take it as a supplement to promote relaxation without drowsiness. It was first identified by Japanese tea researchers in 1949. In foods, L-Theanine is a source of umami: the savory, brothy taste.


The Scientific Research

Numerous researchers have studied L-Theanine and have demonstrated its benefits in a number of double blind studies published in peer reviewed scientific journals. Studies have found that L-Theanine:

  • increased relaxation without causing drowsiness.
  • reduced stress and anxiety in people who were experiencing stressful situations.
  • lowered resting heart rate.
  • decreased anxiety and improved symptoms for people suffering from schizophrenia.
  • improved immunity.
  • increased the effectiveness of chemotherapy.

The Scientific Research: L-Theanine Combined With Caffeine

A 2013 study conducted by Unilever Food and Health Research Institute, Vlaardingen, The Netherlands, investigated the effects of 97 mg L-Theanine and 40 mg caffeine on cognitive performance, alertness and self reported mood. This was a double blind study, where the control group was given a placebo.

Participants were given a task to complete after 20 minutes and 70 minutes. The group given caffeine and L-Theanine performed significantly better on their tasks than the placebo group. Their concentration improved! They performed better at exercises that involved multitasking, and also reported feeling more alert and less tired than the placebo group.

How L-Theanine Works

  1. L-Theanine boosts levels of neurotransmitters in your brain that promotes relaxation and concentration: GABA, serotonin and dopamine.
  2. L-Theanine lowers levels of brain chemicals linked to stress and anxiety.
  3. L-Theanine promotes concentration by enhancing alpha brain waves. Alpha brain waves are associated with concentration, focus and creativity. They are present during REM sleep (when you experience your most creativity dreams), and are also elevated during meditation.

Potential Side Effects of L-Theanine

L-Theanine can lower blood pressure. People with low blood pressure should consult with their doctor before consuming large quantities of L-Theanine. Otherwise, it is generally well tolerated with no other known negative effects.


How To Get The Benefits of L-Theanine and Caffeine: Sustained Energy and Concentration Without Jitters Or Crash

Both L-Theanine and caffeine occur naturally tea in tea, but most tea drinkers don’t feel the same rush of energy as coffee drinkers. Zest Tea bridges that gap. For both hot tea and sparkling energy tea blends, Zest Tea extracts the caffeine and L-Theanine from tea and adds it back to more tea in order to increase dosage. For every cup of Zest Tea, you get three times the level of caffeine as a regular cup of tea. Zest Sparkling Teas specifically also have three times the amount of L-Theanine you'd find in regular tea.

  • Zest Black Tea: 35mg L-Theanine, 150mg Caffeine.
  • Zest Green Tea: 35mg L-Theanine, 135mg Caffeine
  • Zest Sparkling Tea: 100mg L-Theanine, 150mg Caffeine

Zest Tea is available hot and cold. You can order tea bags, loose leaf, or even try the new ready-to-drink sparkling teas.