A 2012 paper published in Nature posed one of the most controversial questions in brain science.
“Is it nature (genes) or nurture (environment) that determines IQ?” Research results revealed that 50 percent of adult intelligence can be explained by childhood (11-year-old) IQ.
So what about the other factors? It turns out that only a quarter of the changes in IQ, or brain function, across adulthood are determined by DNA.
The remaining three-quarters are determined by our environment and lifestyle, or in other words, by our actions.

---From "Entering"

It is revealed that engaging in 'specific activities' in your 20s and 30s can improve your brain health in your 40s and 50s.
The idea that we could slow down the pace of change like this would have been laughed at just 20 or 30 years ago.
But new research goes further, showing that it's never too late to improve your brain health.
---「Chapter 1.
From "The Brain That Gets Younger Every Day"

The impact of neuroscience on our daily lives is rapidly increasing.
I will try to clear readers' doubts by presenting a few examples.
All of this has happened over the past two years.
There are many things that are very surprising and threatening.


· It became possible to connect the brain to a computer.
It is an innovation with tremendous potential and risk.
An intriguing study conducted at the University of California, San Francisco, showed that computers can recognize brain signals and translate them into words.
As of late 2020, several American companies are developing brain-machine interfaces, including Elon Musk's Neuralink.

· A study conducted in April 2019 showed that the adult brain continues to generate new neurons into the 90s.
This means that even in our 90s, our brains continue to renew themselves.
This is clear evidence of neuroplasticity and the potential for maintaining brain health and function over time.
· It has been found that high-sugar foods reward the brain in exactly the same way as drugs like cocaine or heroin.
· A new type of electrical signal has been discovered in the human brain that distinguishes humans from other species.
· The U.S. Food and Drug Administration has approved Spravato, a nasal spray medication, to relieve depression in adults.
· There is a chilling study that has had a profound impact on the concept of consciousness.
Challenging the perception that brain death is a terminal condition, Yale researchers successfully revived the brains of pigs that had been euthanized and had their torsos removed four hours later.

· In relation to our consciousness, scientists have created 'mini brains' with the ability to think.
Here, the mini-brains are clusters of neurons, each 5 to 6 millimeters in size, grown in the laboratory.
It organizes itself into a brain-like structure.
This discovery conjures up nightmares of “disembodied brains” trapped in a cycle of eternal suffering.

· American company Biogen received approval for Aducanumab as a treatment for Alzheimer's disease.
Their achievements were a great shock to many pharmaceutical companies that had not been interested in neurotherapy.
Our society still has no cure for the 400 neurological disorders classified by medicine.

---「Chapter 1.
From "The Brain That Gets Younger Every Day"

A 2011 National Institute of Scientific Research report cited a study of 120 older adults that found that aerobic exercise increased the size of the hippocampus, which led to improved memory.
When people exercised regularly, their hippocampus grew in size by 2 percent per year, effectively reversing the age-related decline.
As most people pass middle age, the hippocampus loses about 1 to 2 percent of its size each year.
Scientists have discovered that this phenomenon is closely related to memory loss.
But regular aerobic exercise actually protects our neural function.
This is what we want.
(…)

Now I'm going to tell you the horrifying truth.
Even if we exercise daily and exceed the recommended amount of exercise, prolonged sitting can negate all the benefits of physical activity! Sitting is incredibly destructive and wreaks havoc on our bodies.
Data analysis suggests that for every additional hour of sitting per day, mortality increases by 2 percent, and for every additional hour of sitting per day exceeding 8 hours, mortality increases by 8 percent.
A sedentary lifestyle, coupled with persistently low levels of physical activity, increases the risk of nearly every major chronic disease, including heart disease, high blood pressure, diabetes, obesity, and cancer.
(…)
---「Chapter 2.
Among the “most detrimental habits to your health”

A recent study of 1,500 older adults found that those who sat for 10 hours a day and got less than 40 minutes of moderate exercise had the same physical and health status as someone eight years older.
Cutting calories alone won't solve this problem.
The solution is to reduce the inflammation caused by sedentary habits, which in the long term leads to increased activity levels and a diet that reduces inflammation.
… research results show that sedentary habits are a precursor to Alzheimer's.
It is estimated that approximately 13 percent of Alzheimer's cases worldwide are the result of inactivity.
It is estimated that reducing sitting time by 25 percent could prevent approximately 1 million cases of Alzheimer's disease worldwide.
---「Chapter 2.
Among the “most detrimental habits to your health”

Humans also have another brain 'inside the body', along with the inside of the skull.
The brain is made up of 500 million neurons, 20 different types of nerve cells and a variety of complex 'microcircuits'.
So to speak, this is our Godzilla brain.
This brain monitors food as it enters the body and records its taste, texture, and condition.
It also controls digestion.
It breaks down food, passes it through the organs, absorbs the broken down food, and manages the process of excreting the residue.
Some parts of the process are, of course, unsatisfactory.
During this time, the second brain continues to communicate with the brain.
…

Serotonin, the 'happiness hormone', one of the brain's most important messenger substances, is not only produced in the brain.
Surprisingly, about 90 percent of all serotonin is produced in the gut, specifically among the trillions of bacteria known as the gut microbiota, or microbiota.
Serotonin is a very important substance that affects our emotional state.
In other words, bad food makes you feel bad.
---「Chapter 3.
From "There is another brain inside my body"

The human body is made up of 30 to 37 trillion cells.
However, according to a paper by Israeli scientists reported in Nature in 2016, there are 50 trillion microorganisms living in the human body.
This means that we are 43 percent 'human' and 57 percent 'microbial'.
No matter how diligently we wash our bodies! Simply put, we are not ourselves.
…about 70 percent of our immune system is found in the gut, where the microbiota plays a role in supporting our immune system by minimizing inflammation and infection.
…the extent of the influence of microbes extends far beyond the emotions of stress or the gut itself.
Recently, it has been discovered that gut microbes have a powerful influence on our thoughts and behavior.
…bacteria enhance their chances of survival by altering our social behavior.
Moreover, there is now evidence that adding certain types of bacteria to the diet of people with social behavioral deficits, such as autism, can alleviate anxiety and antisocial behavior and improve sociability, language, and communication.
---「Chapter 4.
From "Brain and Microbes, a Perfect Community of Destiny"

People who frequently use social media are three times more likely to feel lonely than those who don't, a new study has found.
… analyzed data from a large sample of approximately 20,000 adults aged 17 to 89.
As a result, they confirmed that 'social isolation' predicted the risk of death as strongly as traditional clinical risk factors such as smoking or high blood pressure.
… the increased risk of death due to social isolation, loneliness, and living alone was found to be 29, 26, and 32 percent, respectively.
For example, a lack of social connections is said to be as harmful as smoking 15 cigarettes a day, drinking a bottle of gin, or being morbidly obese.
…

A wealth of social capital throughout life supports our brain health from childhood through old age.
Through all these activities, we can build what psychologists call "cognitive reserve," a cognitive resilience against brain damage.
Cognitive reserve is the brain's ability to identify important challenges and develop alternative ways to overcome them.

---「Chapter 6.
From "The Brain is Not an Island"