Heart Health 

Japanese Heart Doctor Reveals: Why People in Japan Live Longer Than Anyone Else on Earth

By Dr. Kenji Nakamura, MD — Heart Specialist, University of Tokyo
👁 1,847,293 views   ⏱ 5 min read  Last updated March 2025   💬 52 Comments

A morning ritual in Japan that has quietly outlasted every theory Western cardiologists came up with.

Here is something that has puzzled doctors for fifty years.

People in Japan live to 84 on average. In the United States, the average is 76. That is an eight-year gap. Japan also has one of the lowest heart attack rates in the world — and nobody has fully explained either one.

Japanese people eat white rice every day. Many of them smoke. By every measure we use to predict a long life, they should not be winning. But they are.

“I spent thirty years looking for the answer,” says Dr. Kenji Nakamura, a heart doctor at the University of Tokyo. “It turned out to be something they eat for breakfast.” 
Dr. Kenji Nakamura, MD — University of Tokyo

The Sumo Evidence

The 400-Pound Clue

Sumo wrestlers weigh between 350 and 450 pounds. On paper, their hearts should be in serious trouble. But when cardiologists tested active wrestlers, the results did not add up. Lower blood pressure. Cleaner arteries. Better readings than American men who weigh half as much.

Active sumo wrestlers tested by Japanese cardiologists showed lower blood pressure and cleaner arteries than Western men half their size.

“A 400-pound man should not have arteries that clean,” Dr. Nakamura says. “The one thing that set his routine apart was his morning meal.”
Dr. Kenji Nakamura, MD

The Pattern Doctors See

The Warning That Starts at 50

For most men, the first sign is a routine checkup. Your blood pressure is higher than last time. Not scary yet. But it keeps climbing. 138. Then 145. Then 152.

You cut back on salt. You go for walks. It keeps going up. Most doctors say it is just aging. They write a prescription and send you home.

“By the time men come to see me,” Dr. Nakamura says, “they have tried everything. Nothing worked.”
Dr. Kenji Nakamura, MD

The list is always the same:

• Fish oil — good for you. Does not fix the real problem.
• Aged garlic — fights damage. Cannot clean up what has already built up.
• CoQ10 — helps your cells make energy. No effect on the root cause.
• Beetroot — opens blood vessels briefly. Does not clear them.
• Blood pressure pills — push the number down. Do not fix why it keeps going up.

“Every one of those treats the sign. None of them ask why the sign keeps appearing.”
Dr. Kenji Nakamura, MD

They all do the same thing in a different way. Garlic opens the blood vessel. Beetroot opens it. The pill your doctor gives you opens it. Like adding an extra lane to a road blocked by a crashed truck — traffic moves a little, but the truck is still sitting there. None of them remove what is causing the blockage. What Dr. Nakamura found in Japan does something none of those can do.

Some men have already been through all of that and are now on a prescription. Their number is controlled. But they still feel off — cold feet, foggy thinking, waking at 3am. The medication is doing what it was designed to do. It just was not designed to reach the fibrin.

It is like mopping a wet floor while the tap above it is still running. Stop mopping and the floor floods again. Nobody ever closed the tap.

The reading goes down. The cause stays.

What Is Actually Happening

The Real Reason

There is a sticky protein in your blood called fibrin. Your body makes it to heal cuts and injuries. That is a good thing.

The problem starts after 40. Your body keeps producing fibrin at the same rate but gets worse at clearing it. Think of a kitchen drain that slowly fills with buildup over years — the opening gets smaller, the water gets slower. Your arteries do the same thing. Your heart has to push harder every year just to move blood through.

That is why your blood pressure creeps up year after year. And when fibrin goes unchecked, it raises the risk of blood clots — which is how most heart attacks begin.

Your doctor sees the number and gives you something to lower it. But the fibrin is still there.

“Your doctor does not test for fibrin. It is not on a standard blood test. Most men have no idea this is happening.”
Dr. Kenji Nakamura, MD

A 1,000-Year-Old Discovery

What Japan Has Been Eating for 1,000 Years

In 1980, Dr. Hiroyuki Sumi dropped a piece of natto — a Japanese breakfast food — into a dish with a blood clot. A few hours later, the clot was gone.

Natto. The enzyme inside it dissolves fibrin directly.

The enzyme that dissolved it was Shinka . It is the only thing found in food that breaks down fibrin directly. Since then, 17 studies have tested it in real people. The results keep coming back: lower blood pressure, less fibrin, cleaner blood vessels. No serious side effects.

The Japanese have been eating natto every morning for over 1,000 years — a small dose of this enzyme with every breakfast. For most people outside Japan, natto is hard to find and harder to eat. The taste and smell stop most people after one try. To reach the amount the studies used, you would need to eat it every single day without fail. That is where a concentrated supplement comes in. But most products get this wrong.

The Problem With Most Products

Why Most Supplements Still Miss

Every other supplement you have already tried does one thing — it makes the blood vessel wider. Garlic does it. Beetroot does it. The blood pressure pill your doctor prescribes does it. More room for the blood to pass through. But the fibrin is still there. Still building. Every year.

Nattokinase is the only thing that works at a different level. It does not widen the vessel. It dissolves what is narrowing it. Blood moves freely because the obstruction is gone — not because you stretched the pipe around it.

“BP pills widen the pipe. Shinka  removes what is narrowing it.” — Dr. Kenji Nakamura, MD

But most Shinka  products still get this wrong. Two reasons.

First, the dose. Studies use 2,000 to 4,000 FU — fibrinolytic units, which measure whether the enzyme is active. Most products give you half that. But some go the other way and list 10,800 FU or more. That is not better. At those levels the enzyme thins the blood past the point of safety. The research-backed dose is 4,000 FU.

Second, when Shinka  clears fibrin, it frees calcium. Without Vitamin K2 to send that calcium to your bones, it ends up somewhere it should not. Most products leave K2 out entirely.

The Right Formula

The Formula That Gets Both Right

A colleague asked Dr. Nakamura to look at a supplement built around both problems.

The product is called Core Shinka  + K2.

It gives you 4,000 FU of Shinka  — made in Japan, from the same fermented soybean food Dr. Sumi studied. It includes 180mcg of Vitamin K2 MK-7, which sends freed calcium back to your bones.

RiseVitals Shinka + K2. 4,000 FU. Made in Japan.

“This is one of the only products I have seen that gets both things right,” Dr. Nakamura says. “The dose matches what the studies used. The K2 is in there. And the source is real — Japan, not a cheap copy.”
Dr. Kenji Nakamura, MD

The Clinical Evidence

What the Studies Show

17 human studies. The biggest — run in Korea in 2009, with 1,062 people over eight weeks — found blood pressure dropped by an average of 5.5 points. Zero side effects. A second study found fibrin levels and vessel stiffness both improved in the same timeframe.

More than 45,000 people have used Core Shinka + K2. Most report better blood pressure readings in 4 to 8 weeks, more energy, and legs that feel lighter.

The sumo wrestler who stumped those cardiologists was not doing anything unusual. He was eating the same breakfast tens of millions eat every day — the one carrying the enzyme Western scientists spent decades trying to understand. Shinka puts that enzyme in your hands, at the dose that works, in one capsule a day.

IMPORTANT UPDATE — Limited Japan Batch

Because they source directly from Japan, we can only make small batches at a time. The current batch is selling out faster than we expected.

✓ 50% OFF for Health Mag readers — today only
✓ Free shipping on every order
✓ 60-day money-back guarantee — no questions asked
✓ Only 14 units left in this batch

Getting more stock from Japan takes 60 to 90 days. If the page still shows units in stock, the offer is still live.

About the Author

Dr. Kenji Nakamura, MD

Heart Specialist · Shinka  Researcher · University of Tokyo / Johns Hopkins

Dr. Nakamura grew up in Japan and trained as a doctor at the University of Tokyo. He later studied at Johns Hopkins in the US. He has spent most of his career studying why Japanese people live so long — and what the rest of the world can learn from it. He writes for Health Mag about heart health, long life, and the science behind traditional Japanese food.

COMMENTS (52)

Robert D.
March 12, 2025
This is the first time I have seen someone explain the fibrin connection clearly. My cardiologist mentioned "arterial stiffness" but never said what was actually causing it. This makes sense.

James T.
March 15, 2025
I have been eating natto for about 6 months after my wife (she is Japanese American) started bringing it home. My last checkup my doctor said my numbers had improved noticeably. Could not say for certain what caused it but I thought of this article immediately.

Michael S.
March 17, 2025
The sumo wrestler angle is fascinating. I had never thought about why they do not have the cardiovascular complications you would expect given their size and diet. It actually does suggest something else is going on.

David K.
March 18, 2025
Dr. Nakamura, do you know if the Shinka in supplement form is as effective as eating actual natto? Asking because finding quality natto where I live is basically impossible.

Thomas B.
March 22, 2025
What I appreciate most is that this article actually explains the mechanism. Most articles just say "eat less salt" or "exercise more." This is the first time I have understood why my blood pressure keeps creeping up even though my lifestyle has not changed.

Steven P.
March 28, 2025
Good article. The Sumi/1980 story is well documented. I would add that the K2 inclusion is the right call. A lot of Shinka products skip it, and it is where most calcification questions get answered.

James M.
April 08, 2025
Wish I had read something like this five years ago. I am 56 now and have been on lisinopril for three years. Reading this made me want to ask my doctor about Shinka at my next appointment. Anyone here had luck combining it (carefully) with their meds?

Frank L.
April 15, 2025
Sent this to my brother in Florida. We have both been creeping into the borderline range and his doctor has been hinting at medication for the better part of a year. We are both going to try the protocol and compare notes in three months.