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Green tea is a plant native to the world’s eastern countries.
It has been consumed very heavily for centuries in places such as China and India, but has only recently gained any popularity as a beverage here in the western world.
And interestingly, they were on to something.
Tea is actually the most consumed beverage in the WORLD, coming in second to water.
Within this, approximately 80% of the tea consumed is black, with only a mere 20% of the tea consumed being green.
This is a little unfortunate, because green tea could arguably be the healthiest beverage on the planet!
You see, all teas (we are talking about REAL teas, not herbal teas) are brewed from dried leaves that come from the Camellia Sinensis, a bush native to Eastern Countries.
The level of oxidation the leaves of this plant undergo determines the type of tea.
Black tea comes from highly oxidised leaves, hence its black colouring. On the other hand, Green Tea is made from un-oxidised leaves.
As the leaves are yet to undergo oxidisation, they still contain large amounts of polyphenols, antioxidants, and essential nutrients.
It is these chemicals that are found in vast amounts in green tea that can have seriously positive effects on the human body.
These include improved brain function and cognitive capacity, a lowered risk of developing cancer, and can even aid fat loss (among MANY other amazing health benefits!).
In this article we are going to look closely at the scientifically proven effects that green tea can have on health!
If you take a closer look at any of those fancy ‘fat burning’ supplements you see advertised on TV, you can guarantee it will have green tea (or green tea extract) listed as a core ingredient.
And there is a very good reason for this.
Green tea has repeatedly demonstrated the capacity to increase fat metabolism and metabolic rate in humans.
In some specific studies, it has actually shown to improve resting metabolic rate (the amount of energy we burn doing NOTHING!) by 4%.
While this may not sound like much, the accumulated effect of a 4% increase in resting metabolic rate over 6-8 hours becomes quite significant .
In conjunction with this increase in energy expenditure, green tea has also demonstrated an increase in fat metabolism by up to 17%.
These two factors work together to create a very positive fat burning environment.
By mobilizing fat and making it more available to use for energy, while also increasing the amount of fat we need to use to maintain our base metabolic rate, green tea promotes an increased rate of fat loss .
Something most people don’t know about green tea is that it actually contains a considerable amount of caffeine.
Now, green tea does not contain as much caffeine as coffee, but it does provide a fairly significant amount (although not enough to produce the ‘jittery’ feelings that some experience with coffee).
And while caffeine has gained a solid reputation as a pretty effective stimulant, it has another key benefit that is emphasised with the consumption of green tea.
Caffeine actually stops a neurotransmitter called Adenosine. Adenosine is what is called an inhibitory neurotransmitter, as it stops or inhibits neural processes.
By stopping the action of Adenosine, we can increase the firing rate of our cognitive neurons, while simultaneously increasing the concentration of positive neurotransmitters (including the feel good neurotransmitter dopamine).
This leads to significant improvements in brain function, mood, memory, and even reaction time.
Additionally, green tea also contains an amino acid called L-Theanine.
L-Theanine has the ability to move from the blood into the neural tissue of the brain, where it increases the activity of the neurotransmitter GABA.
GABA is another inhibitory neurotransmitter that actually reduces our feelings of anxiety, and by increasing its activity we can see significant improvements in mood.
So by drinking green tea, we can get the positive effects of both caffeine and L-Theanine, observing a significant increase in brain function, memory, and mood, without getting any feelings of discomfort or jitteriness [11, 12].
Not only can green tea improve cognitive function, it also has the capacity to protect the brain as we age.
Both Alzheimer’s and Parkinson’s disease are what is considered a neurodegenerative disease, and are currently the two leading causes of dementia in humans, respectively.
The compounds found in green tea have been shown to have positive effects on the neurons of brain tissue. This, in turn, limits the degeneration of neural tissue that is associated with aging.
As a direct result, drinking green tea often can cause a significant reduction in the likelihood of developing these neurodegenerative diseases, helping us maintain cognitive function as we age .
Type II Diabetes is a disease that has been increasing significantly over the last few decades, now reaching an epidemic proportion, type II diabetes affects approximately 300 million people around the world.
Type II diabetes is typified by high levels of resting blood sugar and a resistance to the hormone insulin.
Insulin is a hormone that stimulates the storage of blood sugar into the active tissues of the body, and as such, resistance to insulin is likely to result in a subsequent increase in resting blood sugar levels.
Green tea has shown to acutely increase the body’s sensitivity to Insulin, while also reducing blood sugar levels. This ultimately creates the ideal scenario for reducing the risk of developing type II diabetes.
In fact, a study undertaken on people within the Japanese population found that those individuals who drank a lot of green tea to be at a massive 42% lower risk of developing type II diabetes.
This suggests that drinking green tea regularly can go a long way to prevent the onset of type II diabetes [6,7].
Cancer is one of the world’s leading causes of mortality. It is caused by the uncontrollable growth of malfunctioning cells, and can be extremely difficult to treat.
What a lot of people may not realise is that it is the oxidative damage to our cells that can lead to this uncontrollable cell growth, and as a result, cancerous cells. As a result, the consumption of antioxidants can play an important role in reducing the risk of developing cancer as it limits the oxidisation (and oxidative damage) of cells within the human body.
And, as mentioned above, antioxidants are found in extremely high amounts in Green Tea.
It therefore makes a lot of sense that drinking green tea can reduce our risk of developing cancer!
This has actually been proven time and time again by human research studies. It has been demonstrated that females who drink green tea often are 22% less likely to develop breast cancer. Similarly, men who drink green tea regularly are 48% less likely to develop prostate cancer.
This suggests that drinking green tea can directly reduce the risk of developing cancer in both men and women .
We know that green tea contains an abundance of antioxidants, but it also contains important compounds called polyphenols.
These polyphenols (two in particular: Flavonoids and Catechins) reduce the formation of free radicals in the human body .
Free radicals are compounds that damage organic cells and molecules, can promote inflammation and disease, and also play a key role in cell ageing.
By reducing the formation of these compounds, green tea can limit inflammation in the body, while also improving immune system function. This results in a reduction in our risk of developing illness and disease.
Additionally, green tea also contains essential minerals and nutrients that are essential to the healthy functioning of the human body.
By drinking green tea, we ensure we have these nutrients available in the body, limiting the liklihood of developing any nutritional deficiencies and the negative health affects associated .
Cardiovascular diseases are the world’s largest cause of mortality.
These include strokes, heart attack, and heart disease, and are often associated with an increase in levels of blood cholesterol and blood triglycerides.
Due to the antioxidant profile of green tea, its consumption can rapidly increase the antioxidant capacity of the blood. This significantly reduces the oxidisation of blood cholesterol, and blood triglycerides, while also promoting their breakdown and metabolism.
Collectively, this lowers the risk of developing a number of cardiovascular diseases.
This has been demonstrated by a 31% reduction in cardiovascular disease in those who drink green tea regularly [4,5].
The regular consumption of green tea has a host of benefits to our health.
Due the large amount of antioxidants and polyphenols it contains, it can protect our cardiovascular, metabolic, and neural system from disease and degeneration, significantly reduce our risk of developing cancer, while also improving our mental capacity and overall health.
Not to mention it can also promote fat loss!
It is arguably the most beneficial natural, health supplement available today!
1. Scott, P (2013) Health Benefits of Green Tea, WebMD. Retrieved from: http://www.webmd.com/food-recipes/health-benefits-of-green-tea
2. Ware, M (2016) Green Tea: Health Benefits, Facts and Research, MNT. Retrieved from: http://www.medicalnewstoday.com/articles/269538.php
3. Suzuki, E et al., (2009) Green Tea Consumption and Mortality Among Japanese Elderly People, Annals of Epidemiology. Retrieved from: http://www.sciencedirect.com/science/article/pii/S1047279709001653
4. Kuriyama, S et al., (2006) Green tea consumption and mortality due to cardiovascular disease, cancer, and all causes in Japan, JAMA. Retrieved from: http://www.ncbi.nlm.nih.gov/pubmed/16968850
5. Kuriyama, S (2008) The relation between green tea consumption and Cardiovascular Disease, ASN. Retrieved from: http://jn.nutrition.org/content/138/8/1548S.short
6. Iso, H et al., (2006) The relationship between green tea and total caffeine intake and risk for self-reported type 2 diabetes among Japanese adults, AIM. Retrieved from: http://www.ncbi.nlm.nih.gov/pubmed/16618952
7. Huxley, R et al., (2009), Coffee, Decaffeinated Coffee, and Tea Consumption in Relation to Incident Type 2 Diabetes Mellitus, JAMA. Retrieved from: http://archinte.jamanetwork.com/article.aspx?articleid=773949
8. Pan, T (2003) Potential Therapeutic Properties of Green Tea Polyphenols in Parkinson’s Disease, D&A. Retrieved from: http://link.springer.com/article/10.2165/00002512-200320100-00001
9. Fujuki, H (2002) Green tea: cancer preventive beverage and/or drug, Cancer Letters. Retrieved from: http://www.sciencedirect.com/science/article/pii/S0304383502003798
10. Venables, M (2008) Green tea extract ingestion, fat oxidation, and glucose tolerance in healthy humans, AM J CLIN NUTR. Retrieved from: http://www.ncbi.nlm.nih.gov/pubmed/18326618
11. Dulloo, A et al., (1999) Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans, AM J CLIN NUTR. Retrieved from: http://www.ncbi.nlm.nih.gov/pubmed/10584049
12. Kelly, S et al., (2008) L-Theanine and Caffeine in Combination Affect Human Cognition as Evidenced by Oscillatory alpha-Band Activity and Attention Task Performance, American Society for Nutrition. Retrieved from: http://jn.nutrition.org/content/138/8/1572S.long
John has been a fitness enthusiast for over 10 years, starting out while struggling with obesity as a teenager. Over the years he has advised numerous clients on how to transform their physiques and their lives. As a writer on Nutrition Inspector he aims to help others achieve real results by staying clear of the common hype and false claims in the supplement industry! You can contact him via the "About Us" page.