The main reason many of us drink any form of tea is for the caffeine content. Green tea is no different. While there are forms of green tea that are caffeine-free, most will still contain caffeine and that means they can offer all the same benefits.
Caffeine affects the brain in a great many ways, but among the biggest benefits are its ability to combat drowsiness. It does this by blocking the adenosine receptors in our brain and when you do that, you prevent adenosine from acting on neurons as it normally would. Adenosine is an inhibitory neurotransmitter (meaning it suppresses brain activity) and it is also a by-product that is produced by the brain using any form of energy-intensive function. This builds up during the day and makes us tired. But when you consume caffeine, you reverse this process and wake yourself back up!
Whenever you trigger one change in the brain, it is important to consider how this impacts other parts of the brain too.
In particular, when you alter one neurotransmitter, this will almost always result in others changing too. When you reduce adenosine, this wakes the brain up and it increases activity across all of your connectome.
The brain responds to this by assuming that something important must be happening and therefore it will increase the production of dopamine, norepinephrine and other neurotransmitters associated with focus and attention.
This helps us concentrate and get more done.
When you increase your focus, this will also increase your memory. From the perspective of the brain, anything that is deemed to be important should also be more worth encoding and memorizing.
Thus, the increase of neurotransmitters related to focus will automatically increase the production of those related to BDNF and others related to memory.
Thus, studies show that when you consume caffeine, you are less likely to forget important details.
BDNF is brain derived neurotrophic factor. In case you haven’t heard of it before, this is essentially a neurotransmitter that is responsible for a very specific form of memory called ‘neuroplasticity’.
This is the brain’s ability to grow and to adapt and to form new connections. This is the main process through which learning occurs and it is crucial for our cognitive health and wellbeing.
When you increase dopamine through caffeine, you also increase BDNF.
Many of us may assume that all this sounds too good to be true. If caffeine really wakes you up and boosts performance that much, then what is the cost? Is it ultimately bad for your brain in the long term?
Well actually, the opposite appears to be true. According to studies, drinking a coffee a day at least can actually reduce your chances of developing Alzheimer’s! The reason for this may be to do with the increased BDNF and learning potential of the brain.
Here, the old adage of ‘use it or lose it’ may well apply.
The problem with all this increased focus and alertness is that it is essentially tantamount to the ‘fight or flight’ response, or in other words, the stress response. With all that caffeine flowing through you, you can become jittery, anxious and prone to insomnia.
And this is the first time we see the benefits of consuming green tea specifically as your chosen source of caffeine. That’s because green tea also contains other important benefits, including l-theanine. L-theanine is a xanthine like caffeine but one that has the opposite effect, in that it reduces the effects of the excitatory neurotransmitter glutamate, while increasing the production of the inhibitory neurotransmitter GABA.
The result is that green tea can cause a kind of ‘calm focus’ that isn’t possible with coffee or black tea.
7. Social Confidence
This is why many people will use l-theanine and caffeine together as a ‘nootropic stack’.
Benefits of combining these things include a kind of increased calm and focus during social interactions which can translate to generally smoother behavior.
Consuming green tea may help to make you more charming and charismatic, while staving off symptoms of social anxiety.
8. Weight Loss
Green tea is fantastic for weight loss because it contains ingredients that act as fat burners. Caffeine alone does this, but so too do other metabolic enhancers included in many green teas.
The result is that the body speeds up and becomes better at burning through fat and also using carbs for energy.
As we will see, green tea is also beneficial for maintaining blood sugar levels, which can have a positive knock-on effect on weight loss.
9. Blood Sugar
Green tea appears to be effective in regulating and modulating levels of blood sugar and thereby helping to avoid peeks and troughs in terms of energy.
When we consume carbs, the body will often be hit by a sudden surge of sugar which is followed by a surge of insulin, triggering the rapid absorption and storage of that energy.
By drinking green tea, you can reduce this effect and thereby enjoy a steadier and healthier blood sugar level throughout the day.
This in turn will help you to avoid storing fat and it could also be very instrumental in combating and managing diabetes.
10. Blood Flow
Green tea is rich in polyphenols which include catechins. These have many positive benefits throughout the body, including the ability to increase blood flow by dilated the blood vessels.
This is highly beneficial as it can help to reduce the risk of blood clot, stroke and heart attack. It reduces blood pressure and can also help to prevent stress.
However, it also has the benefit of increasing blood flow to the brain, to the muscles and to the organs. This delivers more oxygen, more nutrients and more glucose, allowing you to perform better and for longer without feeling tired out.
Be careful when using green tea with blood thinners however.