IS GREEN TEA BAD FOR YOUR KIDNEY(S)?

Kei Nishida
4 min readSep 26, 2022

--

You will probably recognize that one of the more recent trends in the world of foods and beverages is understanding what is healthy for the body. A quick search online reveals that there is much to know not only about the body but the impact various substances have on our body. The idea behind green tea is that it’s healthy and for some, this healthy component brings up important distinctions such as “catechins”.

This article will review another area of green tea and our bodies, namely whether green tea is healthy or unhealthy for your kidney(s).

WHAT DO YOU KNOW ABOUT YOUR KIDNEY(S)?

You have two kidneys and they are bean-shaped organs approx. the size of a fist that is situated below your rib cage on each side of your spine. Each kidney is made up of roughly a million units called nephrons. Each of your nephrons has a filter called the glomerulus and a tubule. The glomerulus filters your blood and the tubule returns what is necessary to your blood. Blood flows to your kidney via the renal artery which is a large blood vessel that splits until your blood reaches the nephrons. Your kidneys filter approx. 150 quarts of blood a day, most of it is returned to your body.

Your kidneys have a higher blood flow than your brain and liver. It is a unique organ given most of us start with two yet only require one-half of a kidney to filter our body’s blood. In an odd relationship with your liver, kidneys may also produce vitamin D if the liver cannot. Another important component of our kidneys is that they make hormones that directly help control blood pressure, create red blood cells and keep your bones healthy.

Healthy kidneys are important. Due to the functions kidneys perform and the harmful substances that may move through them they are susceptible to several issues including kidney failure, kidney stones, uremia, and chronic kidney disease among many others.

GREEN TEA AND YOUR KIDNEYS

Of course, drinking green tea affects your kidneys, but how?

We talked briefly about catechins and their impact viz-a-viz the liver. Let us spend a few more minutes on the most common catechin found in green teas and its support in preventing Chronic Kidney disease: Epigallocatechin-3-gallate or EGCG. When discussing chronic kidney disease, we have a form of kidney disease that slowly yet progressively leads to a loss in renal function. One of the more common causes of chronic kidney disease is, yes, diabetes (As a quick note, green tea may help lower the risk of type-2 diabetes). However, it may also include hypertension, obstruction, and other issues. Kidneys can be exposed to harm like any other organ in the body. Kidneys in many are at a high risk of oxidative stress.

Oxidative stress can lead directly to chronic kidney disease and its progression. None of this sounds good but EGCG has been shown to support your kidneys and help stave off renal decline. Further, The American Journal of Clinical Nutrition has also shown that green tea may help regulate blood sugar which is not only good for staving off chronic kidney disease but assists diabetics in their struggles with blood sugar levels.

According to the Chinese Medicine Journal, a 2010 literature review noted that green tea consumption has been linked to the prevention of cancer in kidneys (among many other parts and organs of the body). This is largely due to the sheer number of polyphenols which are in fact antioxidants. In this review, the authors also highlight that green tea has been linked to lower blood pressure which directly benefits the overall functionality of our kidneys. Conversely, the Heart and Stroke Foundation states that over a given amount of time, relatively high blood pressure can cause arteries around the kidneys to narrow, weaken or harden. This may lead to an inadequate amount of blood being sent to the kidneys.

Of course, there are concerns related to kidney stones and green tea. A recent study in the journal Nutrients concluded that green tea consumption does not lead to kidney stones. Chinese researchers, in reply, have found that green tea extract, for example, changes the shape of calcium oxalate and makes them less likely to band together thus easier to move through the kidneys. Studies have shown that there is no link between the substance of green tea and damage to one’s kidneys.

Click here to read the Full Article

--

--

Kei Nishida

CEO, Japanese Green Tea Co., Green Tea Scholar, Merchant & Connoisseur.