L-theanine and the Curious Longevity of the Japanese

December 19, 2021

L-theanine and the Curious Longevity of the Japanese

The Japanese live longer than any other G7 nation. In part, that is because of lower rates of obesity. They have less heart disease, prostate, and breast cancer. They eat more fish and seaweed (iodine). And they drink green tea. As they immigrate to America, those differences go away in proportion to their maintaining their Japanese lifestyle and diet.

Ah, Green tea! What makes green tea different from other teas is the amount of L-theanine. L-theanine is a non-essential amino acid that plays a role in producing many beneficial neurotransmitters. And green tea has been found to be inversely correlated with Japanese cardiovascular disease and mortality. In fact, the more they drink, the longer they live. One cup a day has detectable differences, but five cups a day is proportionately better.

There is a lot written about the effects of green tea and its L-theanine. It appears to reduce anxiety and helps mellow you out. There is pretty good evidence that it tips the balance to beneficial neurotransmitters in your brain. That helps you get to sleep, and sleep a little longer. We know that longer sleep is associated with better brain health as it gives you more time for your brain to be flushed out of its accumulated toxins.

We also know that brain volume and size correlates with all-cause mortality. We want a healthy, large brain. As a general rule, we all have a gradually shrinking brain for which the loss of 50,000 neurons a day is the butt of Saturday Nite Live comedy. But that loss is not inevitable. It is a problem of brain chemistry.

Might there be another solution? With the advent of knowledge of plasmalogens, we know that plasmalogens are the antioxidant of first resort in your cells. They have a vinyl-ether bond right on the surface of the cell membrane. That chemical structure is what soaks up and neutralizes peroxide. Peroxide is the chemical a stressed-out, dying cell releases as it frantically tries to balance its overburdened, broken, internal energy systems. It's the sign that the NAD+/NADH ratio is all out of whack. That peroxide gets excreted and damages other cells around it. One zombie cell damages other cells around it. Your immune system can identify those damaged cells by "lipid peroxidation" on the surface. That's a polite way of saying they have used up all their plasmalogen protection and can't protect themselves anymore. They have used up their plasmalogens and peroxide is tagging the lipids as "damaged". Your immune cells than kill off that zombie cell, quickly before it damages too much else.

What does green tea do to that formula? The antioxidant quality of l-theanine has been shown to be able to neutralize 0.4 ppm peroxide. This allows your cells to not deplete their plasmalogens. Over time, that contributes to your brain not shrinking. Plasmalogens make up some 70% of your axons and synapses, so you have quite a reservoir, but not an endless one. Gradually shrinkage over decades sounds normal. It's not. Shrinkage correlates with death. And we are back to the formula, large brain = long life. Maintaining brain volume is maintaining lifespan.

www. What will Work for me? Goodness, gracious. I like drinking hot liquids as something to sip on while I work. Green tea is easy to substitute. And 200 mg of L-theanine at bedtime. That's easy too. I had seen the evidence before of Japanese having less cancer while living in Japan and I knew about their longevity. Now, the link to green tea and the connection to plasmalogens fits and makes good sense. I look back on a trip to China I made 10 years ago and was lectured by a "professor of tea-ology" about the benefits of green tea. He was right. Pompous, and taken with himself, but right.

References: Feel, Prevention Watch, Pharmcogn Mag, Ann Epidemiology, Jr Polish Biochem Society, Researchgate,

Pop Quiz

1. What is the key difference between green and black tea?                          Answer: L-theanine

2. There are different kinds of green tea. Is any one particularly better?                Answer: well, matcha green tea is shaded prior to harvest. That makes for more L-theanine. (Quite a lot more-so make guide your choices.)

3. What does green tea do to my sleep?                           Answer: It probably will help a little by calming you and producing beneficial neurotransmitters.

4. And how does it help me live longer?                      Answer: This is hypothesis so far, without clear proof, though all the elements are in order. It has potent antioxidant qualities and is shown to help preserve plasmalogens. Loss of plasmalogens has been shown to be the pathway to brain shrinkage and earlier mortality.

5. How much green tea should I drink?                             Answer: Some. More is better. The Japanese who drink 5 cups a day showed proportionately higher benefits.