GABA Tea: Science, Standards, and Sensory Appeal

GABA-Enriched Products in Everyday Life

In Japan, convenience store shelves stock a wide array of items boosted with GABA—from rice, cookies, chocolate, and candy to sodas, soy milk, coffee, and tea. Proponents assert that GABA can ease various ailments and even benefit bodybuilders. The purported advantages of GABA-fortified foods and drinks have gained such traction in Japan that these products are now common in the national diet and culture. Taiwan and Thailand are also moving in this direction.

What Is GABA?

Gamma-aminobutyric acid (GABA) is a compound the brain produces from glutamate and serves as a key neurotransmitter for the central nervous system. Sometimes called “nature’s Valium,” GABA reduces neuron activity, which helps stop anxiety- and stress-related signals from reaching the brain’s motor centers, promoting bodily stability and calm.

Natural Presence and Scientific Discovery

GABA occurs naturally in Camellia sinensis. Research by Japanese scientists has led to a processing method that substantially raises GABA levels in tea. Dr. Tsushida Tojiro is credited with discovering in 1987 that exposing freshly picked tea leaves to anaerobic conditions (without oxygen) converts the leaves’ glutamic acid into GABA, and that processing leaves in a nitrogen-rich atmosphere yields significantly higher GABA concentrations. Subsequent study found that shading tea leaves for ten to fifteen days before picking increases glutamic acid levels, which in turn leads to even greater GABA concentrations.

How True GABA Tea Is Made

Today, authentic GABA tea—available as green and oolong—is produced in Japan and Taiwan. Freshly picked leaves are placed in stainless steel vacuum drums, where oxygen is removed and replaced with nitrogen. To maximize GABA concentration, leaves stay in the container for eight to ten hours and are heated above 104 degrees Fahrenheit. The container is then shaken continuously for up to three hours under aerobic conditions (oxygen is reintroduced). These steps may be repeated several times before steaming or rolling, followed by a final drying. As with all tea production, other methods certainly exist.

Regulatory Standards in Japan

All tea sold as GABA in Japan must meet strict minimum standards. Under Japanese government standards, GABA tea must contain at least 150 milligrams of GABA per 100 grams of tea. Although the discovery is Japanese, most GABA tea available in the US comes from Taiwan, where the process has been enthusiastically adopted along with the tea’s reputed positive effects. Taiwanese GABA tea is also sold in Japan, so its manufacturing standards comply with the strict law there.

Health Claims and Medical Skepticism

Beyond tea’s general health benefits, increased GABA in tea is believed to reduce stress and anxiety, improve memory and alertness, aid weight loss, and act as a natural sleep aid. However, tea is not medicine, and the potential positive effects of GABA are certainly not achieved by simply sipping tea. It should be noted that many doctors doubt GABA supplements help. Physicians at New York University’s Langone Medical Center are skeptical that ingesting GABA does anything for the brain, writing that “when GABA is taken orally, GABA levels in the brain do not increase, presumably because the substance itself cannot pass the blood-brain barrier and enter the central nervous system.”

Potential Risks of Excessive GABA

Too much of a good thing could become a bad thing. If GABA levels are too high, an individual may experience nausea, numbness, impaired memory, increased anxiety, shortness of breath, and tingling in the extremities. Some research suggests that abnormal GABA levels may even cause seizures. Such warnings are directed to individuals taking GABA supplements, particularly since the industry is not regulated. Resources for testing GABA levels are available online, and if there is genuine concern, consulting a physician is recommended.

Aroma and Flavor Profile

Setting science aside, GABA tea does have a distinctly different aroma and flavor profile. Common descriptors include woody aroma, pleasant fruity sour notes, silky smooth liquid, and some Taiwanese GABA oolongs have overtones of cinnamon that evolve in the cup and linger on the tongue.

The GABA-enhancing process raises the levels of catechins called gallate esters in the tea leaves. Esters, familiar to those who work with flavoring oils, are responsible for the aroma of many fruits, vegetables, herbs, and spices. These esters, not necessarily acting alone but leading the charge, contribute to the unique aromas and flavors of GABA tea.

Growing Availability

Although not yet widely known in the west, GABA tea is slowly but steadily finding its way into more shops, websites, and home pantries. Initially purchased out of curiosity or for the touted benefits, once in the cup its deliciousness that seals the deal.