Green Tea’s Secret: Can EGCG Boost Longevity?
Tea has long been believed to have medicinal properties with the idea emerging around 5000 years ago in China. It turns out the beneficial properties, particularly in green tea, might be more than myths and legends. Epigallocachetin Gallate (EGCG) is a key compound found in most teas. Compared to other teas, green tea has a higher concentration due to it being less processed.It belongs to a family of compounds produced by plants to counter environmental stress. Scientists are now researching whether humans could benefit from these protective properties as well.
Why the Interest?
Epigallocachetin Gallate has been shown to interact with several biological properties related to aging and related diseases. This has made EGCG a key compound in longevity research, however the hype has quickly exploded in the supplement industry where scientific rigor takes a backseat to marketability. In this post we will explore the actual evidence of benefits as well as drawbacks.
Cardiovascular health
Cardiovascular disease is a significant hurdle to a long and healthy life. Two of its common drivers are oxidative stress and inflammation which increase with age. EGCG has been shown, in animal models and human cell cultures, to reduce both of these issues. Furthermore, preliminary animal trials have shown direct heart benefits due to the compound. While the theory is strong there have not been large scale clinical trials to show these results in humans yet.
Neuroprotective
EGCG also is being studied as a neuroprotective compound. Terrible diseases like Alzheimer’s and Parkinson’s are correlated with aging. They are caused by an accumulation of proteins which damage neurons, further activating harmful pathways. There have been great advances in treating the symptoms of these diseases, but it is important to find ways to protect neurons in the first place. Just as in the case of the heart the role EGCG plays in limiting inflammation and oxidative stress could similarly protect neurons. Again, in animal studies and cell cultures EGCG has been shown to reduce markers of these diseases. These are very promising results which need to be shown in human trials.
Metabolism
In simple terms metabolism is the process in which our bodies turn our food into the energy we need to survive. With age, our metabolism becomes less efficient which leads to dangerous metabolic disorders such as type 2 diabetes, metabolic syndrome, and obesity which all compound other health risks. EGCG has been shown to interact with and optimize our metabolism. Importantly the evidence has emerged in human trials showing a reduction in obesity. This is an exciting result as chronic obesity has similar causes of diabetes and metabolic syndrome while being correlated with many other age related diseases.
Cancer
Cancer arises due to uncontrolled cell divisions which can be a result of both numerous environmental and genetic factors. This makes it unlikely a compound could fight cancer as a whole, but many can provide benefits to specific causes. EGCG has in fact been shown to target multiple pathways involved with cancer. Animal trials and cell cultures have shown evidence that EGCG has the potential to counter DNA damage and prevent tumor growth. While the evidence in humans is not available yet these are important results.
Lifespan
Finally, is green tea in the fountain of youth? The idea of reversing or prolonging aging has been coveted throughout history and green tea has been said to have this power in ancient China. This idea might have been more than just mythology as a study has shown EGCG to boost healthy lifespan in mice. This concept applying in humans is definitely farfetched however promising due to the shared benefits humans receive from the compound in areas like cancer.
Bioavailability
Despite the exciting evidence, there is unfortunately a big roadblock preventing these benefits from easily being extrapolated to humans. The biggest drawback of EGCG is the current bioavailability, to what extent it is metabolized in our bodies. To play its role EGCG must enter the bloodstream and reach organs such as the brain and heart in its active form. After consumption the compound travels to the small intestine where much of it degrades instead of being absorbed. Because of this it is extremely hard for enough EGCG to enter the bloodstream necessary to replicate strong results from animal and cell trials. Supplements provide slightly better absorption than green tea itself but still below thresholds for significant results. Importantly, there is significant research being done on different delivery methods which increase absorption and allow sustained release for constant levels. This is the path for boosting longevity in humans.
Risk
Another important fact to consider is safety, while tea has been consumed for millenia this still must be explored rigorously. For those with pre existing liver problems there is evidence that significant doses of EGCG could further harm the liver. This is primarily from concentrated supplement form, and not green tea, where the dose is higher and absorbed faster. For those with healthy liver there is no evidence of risk especially with tea consumption for those who would like to play it safe. Still, as different doses and routes of administration are being discovered, safety will need to be tested accordingly.
MOA
EGCG interacts with a couple connected pathways involved in aging. The first one is being an antioxidant. This is a big buzzword in the health industry but essentially EGCG has the potential to reduce reactive oxygen species (ROS) which are harmful byproducts of metabolism that can damage many vital components of our cells. This is called oxidative stress which is a big driver of age related disease. EGCG also appears to activate stress response pathways which respond to energy levels in the cell. This helps the cell recycle damaged components and increases the efficiency of mitochondria reducing their output of ROS. Together these processes reduce oxidative stress and help the cell manage it better. Another place EGCG plays a role in is reducing inflammation which is another crucial driver of age related ailments. Through multiple pathways it reduces signals leading to inflammation. Both inflammation and oxidative stress increase each other in a dangerous feedback loop and the potential to manage this is why EGCG has so much promise.
Bottom Line
It is clear that there is potential for EGCG to provide real anti-aging benefits and the compound is more than just a hyped up supplement. Trials in model animals and human cell cultures have produced exciting results and the pathways it interacts with are well understood. However, it is a large jump to go from there to tangible and reproducible results in humans with the largest hurdle coming from the bioavailability of the compound.
Until advanced delivery methods are widely available, drinking green tea or consuming concentrated supplements are the options available to us. Based on current research I believe for a healthy person the possible benefits that may come from consuming green tea far outweigh the negligible risk of the drink that has been consumed for centuries. A couple glasses a day can be a small part of a routine (along with sleep, exercise etc..) of healthy habits to aim for a long and healthy life. Concentrated supplements do provide a boost in absorption that comes with a very slight increased load on the liver. Again, the benefits outweigh the risks but the gap is smaller, along with green tea’s other benefits: taste, caffeine and cost. I will be sticking with my daily cup.