Everyone by now has probably heard about the many health benefits of drinking green tea and how it contains high levels of antioxidants.
But what are the effects of green tea on testosterone levels?
Most of the content one comes across on the web which deals with green tea’s effects on testosterone, oversimplifies and generalizes what “green tea” really is.
There is not just ONE kind of Green Tea!
So before we dive deep into exactly how green tea consumption relates to testosterone levels in humans, us humans should be introduced to a few basic facts about green tea:
There are numerous varieties of leaves that qualify as “green tea”. Jasmine, camomile, and mint, to name a few, all come under the general umbrella of green tea. But they differ immensely in their composition, and thus in their effects on the human body.
The most common variety which is commercialized and sold as green tea is camellia sinensis – so for the sake of simplicity and contextual consistency, let us limit our discussion to it.
Camellia Sinensis, too, varies in its composition based on where it was grown, how it was grown, and how it was processed – a fact which this study examined in the context of commercial varieties of green tea available in Portugal.
Now, when it comes to camellia sinensis (from here on referred to as green tea), it does have some universally accepted health benefits. Studies such as this one are a testament to the fact that all the hype surrounding green tea, has roots in at least some solid scientific foundation.
Green tea does have its benefits owing to the high concentration of some essential flavonoids, which are the catechins:
Epicatechin (EC)
Epigallocatechin (EGC)
Epicatechin gallate (ECG)
Epigallocatechin gallate (EGCG)
These antioxidants have a reputation for being exceptionally potent, and thus, unsurprisingly we come across the expected health benefits ranging from better metabolism to heightened immunity against cancer.
But nothing amazing comes without its caveats in this world, does it?
Green tea is no exception especially when it comes to its potentially harmful relationship with testosterone levels.
Effects of Green Tea on Testosterone Levels
Let us start with some good news. All the scientific literature that addresses this connection is based on studies done on rats.
There is no direct scientific evidence of controlled studies on humans. And when we talk about experiments done with rats while searching for answers that apply to humans as well, we obviously grossly overlook the importance of the placebo effect.
Isn’t it very possible that human testing would reveal vastly different results owing to humans’ belief in the power of green tea to enhance health, and possibly even testosterone?
That said, owing to the massive similarities in the hormonal systems of rats and humans, the results of these studies are worth pondering on.
A Lowering of Testosterone In Rats After The Consumption of Green Tea
1. The Department of Physiology and Pharmacology in Brazil’s Federal University conducted a study in which it was found that a high concentration of green tea resulted in a positive correlation with inhibited testosterone production.
They also concluded that this effect was reversible. Lowering green tea levels brought the testosterone levels back up.
2.This study injected rats directly with EGCG (found in green tea). While the same researchers had earlier concluded that EGCG had significant efficacy in dealing with human tumors in rats, with this study they had intended to study its side effects on the endocrine system.
The results summarized EGCG in playing a major role in diminishing testosterone levels in the blood.
3. Finally, a study done in India on male rodents arrived at results that were startlingly clear in their depiction of the relationship between testosterone and green tea extracts. The researchers studied three groups.
One group was given a “mild” dosage, which was the human equivalent of 5 cups a day, another group was administered a “moderate” dosage which was the human equivalent of 10 cups a day, and finally, the “high” dosage group was given the human equivalent of 20 cups a day.
This routine was carried out on a per day basis for 26 days. After which post-mortem analysis was done on the rats.
The researchers concluded that the green tea extracts suppressed the production of enzymes that were necessary for facilitating normal testosterone production. After 26 days the researchers also reported a reduction in the size of the testicles.
The serum levels of testosterone were reduced by 25% in the mild group and by 78% in the high dosage group.
However, there are a few important things to remember while ingesting this information:
While, as stated earlier, there is a reason to pay attention to these studies due to the similarities between rats and humans, we should remember the following:
All these studies vary in their approach and duration.
No matter how close rats are to humans, they are not humans.
The rats do not actually drink brewed tea, rather are injected with extracts.
The extracts do not represent the kind of tea humans like to consume in its leaf form.
The extracts can have very different compositions.
At times, like in the EGCG study, only one chemical compound from green tea was used.
These studies involved a dosage that was the human equivalent of 5 – 20 cups of green tea.
Thus, looking at the entire picture of the research, we can see that it is not even remotely close to being representative of humans consuming green tea.
There is definitely something going on with green tea and testosterone though. Even if we set aside the endocrine research on rats, there is still the added threat of high levels of fluoride that can be found in green tea.
Fluoride, in high concentrations, has been linked to major negative effects on biological systems and can lower testosterone. For example, this study mentions a significant volume of research that has concluded that even low levels of fluoride can cause oxidative stress and cellular damage.
Conclusion
I hope this article has given you some information about the link between green tea and testosterone levels.
From all these studies we can conclude that drinking any more than 5 cups of green tea each day could be detrimental to testosterone levels.
