Originating in Japan and introduced in the late 1980s, GABA oolong is a type of oolong tea containing high levels of gamma-aminobutyric acid (GABA)—an amino acid that naturally occurs in the human body and acts as a neurotransmitter. Typically, oolong and green teas tend to have higher levels of this amino acid compared to other teas.
Gamma-aminobutyric acid is naturally produced in the human brain and is also present in many foods containing glutamic acid, including seafood, beans, lentils, sprouted whole grains, and berries. To better synthesize GABA, one may need to increase consumption of foods containing vitamin B6 to further stimulate the production of GABA in the brain. The lack of this amino acid in humans has been shown to be responsible for many mood and sleep disorders.
Research has correlated the consumption of GABA tea with a decrease in high blood pressure. Due to its inhibitory function, it causes the muscles lining the blood vessels to relax, aiding normal blood flow.
Japanese researchers in the 1980s discovered a special tea-processing technique that results in an increase in this amino acid in tea, transforming it into a powerful health tea. By placing the unfinished tea leaves in a sealed chamber devoid of oxygen and pumping in nitrogen to displace any oxygenated air, they created a fermentation process that synthesized the glutamate in the tea leaves into GABA. They also discovered that shading the tea plants for up to two weeks before harvest causes increased levels of GABA.
Flavor and Caffeine Levels
The oxidation level of tea has a great influence on its flavor, and depends on the elevation at which it was grown; the higher the elevation, the lower the oxidation level. High-oxidized teas display darker, richer colors and deeper flavors, whereas lightly oxidized varieties have a more fragrant, smooth, and fruity flavor with a sweet aroma.
GABA oolong has a medium amount of caffeine.
Research on the Health Benefits of GABA Oolong
For the tea to be fully classified as GABA, it must contain a minimum of 150 milligrams of GABA in every 100 grams of dry leaf tea. Research has demonstrated that when brewed, regular oolong tea contains only 0.25 milligram of GABA per 200 milliliters of tea, while the level of GABA-enriched oolong is around 2 milligrams per 200 milliliters. Oolong tea has proven to be beneficial for health as it contains high levels of antioxidants. One study has even shown that, compared to many black, white, and even green teas, oolong tea displayed stronger levels of antioxidant capacity—suggesting it is a top beverage for health and well-being. GABA tea is reported to be a great natural alternative to some pharmaceutical drugs, as it has no addictive properties nor side effects when consumed in moderation.
Lowers Stress and Anxiety
An Australian study conducted in 2019 established the relationship between GABA-enriched tea consumption on stress and heart rate variability (the difference in time between each heartbeat). Stressed individuals typically display an increased level of heart rate variability. Chronically stressed people are more prone to developing cardiovascular illnesses; therefore, it is important for these individuals to minimize their stress levels. The study found that participants displayed a significant decrease in their immediate stress scores and a significant improvement in their heart rate variability levels upon drinking a cup of GABA oolong tea. The results highlight the complex interactions of the nervous system in mood regulation.
Improves Sleep and Mood Disorders
The notable health benefits of GABA oolong include improved sleep in individuals suffering from sleep-related disorders like insomnia. This is largely attributed to the calming effects of GABA, which acts as a natural sedative without any addictive properties. Humans naturally produce GABA in their brains, but it has been suggested that individuals with sleep, depression, and anxiety disorders may have lower levels of GABA, causing sleeplessness and mood-related problems. The amino acid GABA functions as an inhibitor in the brain and, when mixed with L-theanine (found in all tea), it helps to encourage relaxation and improve sleep quality.
Another reported health benefit is enhanced mental focus and concentration. Many Japanese children even drink GABA tea before school to stimulate mental alertness in class.
Drink in Moderation
Researchers recommend it is safe to drink 10 to 20 milligrams of GABA from tea, equivalent to four to eight cups of brewed GABA tea. This is best done in the evenings to help with sleep or mood disorders. The amino acids in the tea are highly soluble so steep time is usually very short—two minutes at most. As with anything, it is important to consume GABA tea in moderation as too much of it may cause nausea, digestive upset, and breathing difficulties.
Today, GABA tea can be found in most specialty tea stores, with Taiwan and Japan being the most common exporters of this tea.
Meditating and Keeping a Healthy Mind
Another way to naturally increase GABA levels in the brain is through practicing meditation and mindfulness. Just as consuming a healthy diet is important for the body, taking care of the mind is a powerful way to deter stress and anxiety.