From cup to health: The Benefits of Green Tea

Another functional drink: Green tea.

Green tea is made from the leaves of the Camellia sinensis plant, and it is well-known for its numerous physical and mental health benefits as demonstrated by the combination of ancient wisdom and scientific research highlighting its essential contribution to wellness and mind-body practices.

The bioactive compounds in green tea exhibit potent antioxidant, anti-inflammatory, and fat-burning properties, which may help reduce the risk of various diseases, including type 2 diabetes, obesity, cardiovascular disease, and cancer.

Green tea has been linked to improved cognitive performance, promoting relaxation and enhancing focus. This is evident from its historical use by Buddhist monks and Zen practitioners, who rely on green tea to maintain alertness and suppress distractions during extended meditation sessions.

Green tea also has neuroprotective properties and antidepressant effects, and provides advantages in the prevention of neurodegenerative conditions like Parkinson's and Alzheimer's.

And not only, it has also been associated with improved oral health, potentially reducing the incidence of periodontal diseases.

From a nutritional point of view, green tea health benefits are primarily due to its rich content of polyphenols such as epigallocatechin-3-gallate (EGCG), the amino acid L-theanine and caffeine. A unique characteristic of green tea is that while caffeine can cause arousal, L-theanine counteracts this effect, leading to a state of calm focus; this is the "magic" of green tea!

Chinese, Japanese and green tea extracts. Are these the same?

Not all green teas and extracts are the same thing. The quality and taste of different green tea varieties are influenced by various factors such as geographical origin, cultivation methods, and processing and brewing techniques.

Carefully controlled processing and the exclusion of fermentation are necessary to preserve the natural freshness of the leaves, while maintaining their antioxidant properties and delicate, refreshing flavour.

For example, in Chinese green tea the leaves are typically pan-fired for a short duration. This method imparts a diverse range of flavours, from nutty and roasted to floral and hearty. Notable varieties of Chinese green tea include Longjing (Dragonwell) and Biluochun.

In contrast, Japanese green tea production centres on a steaming technique, where tea leaves and buds are briefly steamed to prevent oxidation, preserving their natural grassy flavour and vibrant green colour. Key Japanese green teas include Sencha, Gyokuro, and Matcha. Notably, Matcha is created by grinding whole tea leaves into a powder, offering a more concentrated source of beneficial compounds compared to other teas. Dissolving the matcha tea powder in hot water means all its nutrients are consumed, including those that are not water-soluble. To achieve the highest grade, traditional cultivation and production methods must be strictly followed using the finest quality leaves.

In terms of consumption, studies have shown that different brewing conditions can alter the antioxidant strength of the tea. For optimal health benefits, it is recommended that green tea is brewed at lower temperatures (around 70-80°C) and for a shorter duration (2-3 minutes) to maximize catechin extraction while minimizing bitterness.

Most green tea extracts are standardized against catechin EGCG. These compounds are marketed for their role in enhancing metabolic processes, including fat oxidation (the biochemical process where fat deposits are transformed into energy). These effects are dose-dependent, where higher doses of EGCG lead to more pronounced metabolic improvements (e.g., generally benefits are observed at 500 mg of EGCG equivalent per day). Consequently, green tea extracts (also known as GTE, Green Tea Catechins) have been incorporated in high doses into supplements aimed at supporting weight loss. However, excessive consumption of GTE over extended periods (more than 6 months), particularly in very concentrated supplement formulation, has been linked to elevated liver enzymes and potential liver toxicity. In response, the EU Commission has proposed legislative amendments to limit GTE to less than 800 mg of EGCG per day to ensure consumer safety. Although the literature indicates that only a small proportion of individuals experienced liver injury from high-dose EGCG, we would still caution against very high doses of GTE, especially for those with underlying health conditions or genetic predisposing factors. However, green tea infusions prepared in a traditional way, are in general safe.

Conclusion

In conclusion, green tea is a highly beneficial beverage that offers a wide range of health advantages due to its rich polyphenolic content, particularly catechins. For those seeking to incorporate green tea into their diet, selecting high-quality varieties and employing proper brewing techniques are essential to maximize its health benefits.