How a cup of green tea may help support long term brain health

There are approximately 950,000 people with dementia in the UK, and this number has been projected to rise to 1.4 million by 2040, but we are lucky to live in an age where technology continues to advance and interest in reducing the risk of cognitive decline grows. Green tea, as part of a healthy diet, has found its place not only as a comforting drink but also as an evidence-based beverage known to support long-term brain health. 

For centuries, green tea has been celebrated as a source of calm energy, focus and wellbeing. Originating in China more than 4,000 years ago, it was traditionally used for medicinal purposes but later became a daily ritual across eastern Asia. The drink made its way to Britain in the 17th century, though black tea (often with a splash of milk) soon became the more popular choice due to its stronger flavour and longer shelf life. Wind forward to the late 20th Century, and green tea was not only the talk of the town, but it was now making headlines due to its heart and metabolism health benefits, helped along by its new found celebrity following. Now, and most recently, it has made headlines with its brain health benefits. 

Green tea, a caffeinated drink, is packed with powerful antioxidants called catechins which work to protect the body against free radical damage. It also contains a unique amino acid called L’theanine. While caffeine is present in both coffee and tea, L-theanine is exclusive to tea leaves, and it is this amino acid that provides green tea with its link to bettering brain health.

L-theanine can cross the blood brain barrier and when it does, it influences several neurotransmitters, including GABA, dopamine and serotonin – hormones and chemicals that help regulate mood, attention and alertness. When L-theanine is consumed, a state of relaxed focus is experienced, helping to reduce anxiety (cortisol levels) without causing drowsiness. When consumed alongside moderate caffeine (as in green tea), it also enhances cognitive performance, further improving attention, memory and reaction time without creating that feeling of being jittery or overstimulated – effects often associated with coffee. This is because L’theanine tempers caffeine’s overstimulation, working to reduce the body’s stress responses while still maintaining concentration. Therefore green tea has the ability to support cognitive endurance. Regular drinkers of green tea often describe a clearer, steadier form of energy, ideal for the working day or long periods of learning and studying. 

As well as helping the brain on an ‘output level’, green tea benefits the brain’s physiology. Some studies have suggested a possible link between regular green tea consumption and better cognitive function in later life. Research from Japan, where drinking green tea on a daily basis is the norm, shows that individuals who consume several cups per day tend to have better cognitive performance and a reduced risk of dementia. This is due to the combination of L-theanine and antioxidants that work together to protect the brain’s neurons from oxidative stress and inflammation, two key processes that are linked to age-related cognitive decline and diseases such as dementia and Alzheimer’s. Because L-theanine can also bypass the blood brain barrier, improving blood flow to the brain, it further enhances synaptic plasticity (the brain’s ability to form new neural pathways), while reducing the buildup of harmful proteins associated with neurodegenerative diseases. Over time, the brain’s structure and physiology is supported, building cognitive resilience. 

While green tea alone cannot prevent cognitive decline, adding it to form part of your daily diet is a small but meaningful step, as you are creating a habit to help nurture your brain health in the long run. Nutrition and gut health also play a crucial role. The Mediterranean diet, as advised by Professor James Goodwin, consists of foods that are rich in omega-3 fatty acids, flavonoids and polyphenols. Together with green tea, neuro-inflammation can be reduced and neuro-integrity supported. Regular physical activity, quality sleep and social engagement are equally important for maintaining cognitive vitality as highlighted in Brain Health Network’s 6 core, guiding pillars. 

By forming new habits that nourish the brain, you are investing in your future and cognitive vitality. In turn this will help you to stay sharp, feel good and reduce the risk of cognitive decline in later life.

This article is for informational purposes only and not intended as medical advice.