The professor of Pediatrics, one of the 250 most important clinical researchers in the world, explains what lies behind children's learning difficulties and describes the golden rule of longevity: "Number 1 is sleep, 2 is diet, 3 is exercise"
I found myself on a pedestrian street near Ilisia. At the entrance of the building, a large sign read: National and Kapodistrian University of Athens. Medical School. And in smaller letters: Unit of Clinical and Translational Research in Endocrinology. And even smaller: Director: Professor George Chrousos.
The meeting, after much effort and numerous phone calls and messages, had been scheduled for 11:30. I went up together with William Faithful and his magical camera. And we came across a multitude of offices. Medical ones. At the entrance of one of them was written the name of a sleep specialist! In the waiting room, numerous seats and parents with their children. I put on a mask. Always anxious. And we waited. Until Mrs. Eleni appeared, a being whose gaze radiated smiles of genuine kindness. The professor was waiting for us. Time was minimal. Only forty minutes. I got anxious. And so, when I found myself in front of an optimistic, smiling face, I calmed down. And I started.
You might ask, "Who is this George Chrousos?" I will answer by listing a few highlights from his rich, productive, and creative career. Both in the USA and in Greece.
George Chrousos is among the 250 most prominent clinical researchers in the world. He has authored more than 1,100 scientific publications, edited 29 books, and his works have been cited more than 74,000 times. According to the ISI website (which tracks searches for scientific publications), he is the most cited clinical pediatrician and endocrinologist in the world. According to Google Scholar's citation counter, he is the 37th most recognized scientist globally.
He is a professor and chair of the Department of Pediatrics at the Medical School of the University of Athens. He was a senior investigator, head of the Department of Pediatric Endocrinology and Training Program, as well as head of the Division of Pediatric and Reproductive Endocrinology at the National Institute of Child Health and Human Development in the USA. He is also a clinical professor of Pediatrics, Physiology, and Biophysics at Georgetown University Medical School and a distinguished visiting researcher at the US National Institute of Child Health and Human Development.
Shall I continue? Unnecessary. One request: read carefully what he says. It is as useful as it is an invisible and impenetrable personal shield of health!
Scene 1: "Apparently, we are made for 132 years"
Dimitris Danikas (D.D.): I saw your CV and I was blown away. What are all these specialties?
George Chrousos (G.C.): I first studied Pathology, then Pediatrics, and then Endocrinology. These are three very fundamental specialties, as you know.
D.D.: Not just those, there are others... Regarding this announcement you made, can we be young until 200, let's say?
G.C.: Apparently, we are made for 132 years; that is the estimate.
D.D.: Which generation?
G.C.: All generations. Humans are made for 132 years, with an average life span around 105-110. But due to stress, mainly, difficulties, and the pressure we face, we die earlier.
D.D.: But they say stress can also be positive -- part of it.
G.C.: When stress is manageable, it is positive. When you feel you have it under control. Let me give an example. I start doing something that is difficult, but during the day I achieve it. In the end, I feel positive. This is called eustress because I handled it well and controlled it.
D.D.: But when I learn I have cancer, I cannot have positive stress.
G.C.: That is negative stress, first of all psychological. You start thinking, "What will happen to me? Will it progress...?" It is good, though, now that we have ways to deal with cancer, to face it fighting and with hope that we will live many more years. That we will not suffer. And truly, I know women with breast cancer who, if they consider it an enemy they can fight, face it properly, live longer -- and live well.
D.D.: Do what women do with plastic surgery, hyaluronic acid, create problems in the body?
G.C.: No, no, hyaluronic acid cannot do anything bad.
Scene 2: "The older the parents, the higher the chance their children are born with problems"
D.D.: Can one stay young? Don't cells die?
G.C.: Cells die -- and they are programmed to die. But of course, this goes a bit into the future -- we now know how to regenerate a cell. Think that gametes, i.e., eggs and sperm, are new cells, they have returned to a very youthful form.
D.D.: So the cells of a seventy-year-old man in ejaculation are new?
G.C.: These cells are new, but unfortunately, because seventy years have passed, they have accumulated mutations. There have been changes in the DNA. That is why when parents are older, the children have a higher probability of genetic problems, which may manifest in different ways.
D.D.: So, up to what age is it good for a woman to give birth?
G.C.: Ideally, until 37, to complete the cycle. After that, the reproductive system gradually deteriorates, fertility decreases.
D.D.: And this creates problems for the child in the future.
G.C.: Exactly. Many children with learning difficulties, ADHD, fall within the autism spectrum. If you look at them, they have mutations in various genes. And the older the parents, the higher the probability of such conditions.
D.D.: So a mother giving birth at forty may have a higher chance of having an autistic child?
G.C.: If I take statistics and put on one side the age of the mother or father and on the other the probability of a child having a developmental condition, it will be a straight line. There is a correlation -- the older the age, the higher the probability.
D.D.: But prenatal testing is available now, right?
G.C.: It is done for certain diseases, not for all. Not for autism, because autism is polygenic. It will be done someday, when we know all the genes.
Scene 3: "AI should be used by humans as an auxiliary tool"
D.D.: What is the future?
G.C.: The future is, in my opinion, we will reach a time when we can know from genetics if a child has chances of autism, ADHD, or anything else.
D.D.: When will this happen?
G.C.: It will happen in a few years. I wouldn't say five years, but we are close.
D.D.: Will we be able to control births? That is, in the future, decide what child we will have?
G.C.: We will be able to talk in terms of probabilities. That the child has a high probability of autoimmunity, allergy, obesity, or autism. Probabilities, always. Where we have certainty is with a few genes, the so-called monogenic or oligogenic diseases.
D.D.: How are they different?
G.C.: For example, in thalassemia, we know exactly what happens and we treat it. There are now drugs and transfusions, and soon we will have gene therapy. Monogenic diseases will be solved quickly in the coming years because we can insert genes into the genome.
D.D.: So this problem will be solved.
G.C.: Such problems, monogenic, where we know the gene responsible, will be solved. Things are very optimistic.
D.D.: With AI, won't your work be affected? If it tells me "you don't need a doctor, you have this, you have that, do this, do that"?
G.C.: We have learned it, we use AI now. It is good, but we must see it as a lever. It has no judgment, no emotion. And emotion is important.
D.D.: Doesn't it threaten your profession?
G.C.: No, it will improve it. Now, through AI, an X-ray will give us much more information than we can have now. Like the stethoscope, used for 200 years and still in use. But now, with portable ultrasound, we can see inside the body -- I can tell if you have gallstones, something I cannot do with a stethoscope. AI should be used by humans as an auxiliary tool, a lever that increases our capacity to bear greater cognitive load. With 44,000 genes, it is impossible for a person to remember them all.
D.D.: We have that many genes?
G.C.: Yes, each cell expresses 44,000 genes. With AI, which can make large calculations quickly, we will have the result at the push of a button.
Scene 4: "Schizophrenia is a very genetic disease"
D.D.: Isn't the human body unique? Not a copy of someone else, right?
G.C.: Look, between us, humans differ by 1/1,000, but that one per thousand is very significant. It gives us all the characteristics that make us unique. Even identical twins, genetically identical, if in different environments, behave completely differently. Put one in a poor environment, the other in a rich environment -- they will behave differently. For schizophrenia, which is very genetic: if you have identical twins and one has schizophrenia, the probability the other develops it is 50%, not 100%. Because the other 50% is the environment.
D.D.: And how do we know a child has schizophrenia?
G.C.: Diagnosis is easy, clinically.
D.D.: At what age?
G.C.: Relatively early, usually adolescence, called puberphrenia. Severe forms start in adolescence. Earlier, children are odd but do not show the full disease.
D.D.: And schizophrenia has gradations?
G.C.: Of course. Mild schizophrenia, severe...
D.D.: In severe cases, can someone become a murderer?
G.C.: Look, it's wrong to call psychopaths that. Those with diseases like depression, schizophrenia, are not necessarily violent. Many very violent people are neither schizophrenic nor depressed.
D.D.: They are normal. And they are among us.
G.C.: Exactly. 1% of the population has what is called psychopathy -- but psychopathy here means lack of conscience.
D.D.: Conscience for what?
G.C.: They cannot distinguish right from wrong, fair from unfair. But if in a good environment, they live fine. No problem, because they learn from others. And when raised correctly, the child becomes a good person.
Scene 5: "By six years old, logic, morality, all of this is written in our DNA"
D.D.: Parents play a big role.
G.C.: Huge. The first two years are critical because trust is formed -- from the child to the mother. The mother plays a huge role. Then, of course, the father, relatives, siblings, and so on. The first two years are bonding. In the next three to four years, judgment develops -- logic and morality.
D.D.: From what age?
G.C.: By six years, this is complete -- the way we think, logic, how we see others, morality. The sense of justice, innate in humans. Our logic and morality are written in our DNA.
D.D.: And then how does a murderer kill?
G.C.: In American prisons, about 85% of inmates -- men and women -- were abused in the first five years of life. Their parents, relatives, whoever cared for them. These children later develop secondary psychopathy. It's not in their DNA, but because of the abuse, their logic and morality didn't develop properly, so later they have problems.
D.D.: And they vent in this way?
G.C.: Yes, because they cannot control their impulses. This is very important. In the first five to six years, we learn to regulate emotions -- emotional self-regulation. These children do not have that.
D.D.: What is that?
G.C.: The ability of logic to control emotion. You are in a bar, someone annoys you, you feel the impulse to hit them. These children, in a bar, think someone looks at them wrong and they attack. They have the impulse of anger and aggression and cannot control it because they didn't develop self-regulation.
Scene 6: Sleep, diet, exercise, in that order
D.D.: A woman whose husband leaves her and feels really terrible can't control herself, she might do incredible things - even go as far as suicide.
G.C.: Unfortunately, that happens, but not 100% of the time, it's a small percentage. Life is full of stress; we must learn to manage it from a young age. A breakup is a huge stress - though not necessarily for both people.
D.D.: Mainly for the woman?
G.C.: No, for the man it's the same. When a couple separates, it means at least one of them has a problem. One is oppressed and the other oppresses, so to speak. I used to think both would be stressed in a breakup, but often one is relieved and the other suffers. It's not necessary that a breakup affects both equally. The one who suffered during the relationship leaves, relieved. The other suffers behind. Of course, if they've lived together and have children, shared interests, the breakup affects both greatly.
D.D.: What role does sleep play in our lives?
G.C.: Sleep is No.1. A large study was recently conducted in the U.S. on what is most important for human health. They examined diet, exercise, and sleep. The most important, therefore, is sleep. Second is diet, and third is exercise. All three are important, but everyone must make sure to sleep well. This is essential because it helps us handle daily stress.
D.D.: How can we sleep well?
G.C.: At night, we must rest. Many people bring their work problems - or their child's school problems - home with them.
D.D.: Well, that's natural. How do you just leave them behind?
G.C.: We must acquire control skills. In the evening, during holidays, and weekends, we must relax. The body needs stress hormones, like cortisol and others, to drop. When they drop, the brain regenerates, tissues regenerate. If you are constantly stressed, you are always in a catabolic phase. Instead of building, you're breaking down. That's what stress hormones do to help you. When stressed, you produce glucose and amino acids to help, but this cannot continue indefinitely. It helps for a while, but chronic stress has the opposite effect. We must distinguish acute stress, which usually leaves no lasting effect - it's neither harmful nor beneficial - unless it's something extreme.
D.D.: Acute stress isn't very dangerous?
G.C.: You get cut off in traffic, get angry - that's acute stress. Go home, forget it. It doesn't harm you. But if you witness a murder, that's severe acute stress. About 20% of people are particularly sensitive and may develop post-traumatic stress disorder: thinking about it constantly, having nightmares, anxiety. Fortunately, this extreme stress is rare; 80% of people recover. The 20% who are vulnerable are why the U.S. military screens soldiers for frontline deployment, to prevent long-term health system strain.
Scene 7: Beneficial Delta waves
D.D.: What portion of the population suffers from sleep problems, stress, or abuse?
G.C.: Abuse is unknown, as much happens at home and is hidden due to stigma.
D.D.: And sleep, are there statistics? How many Greeks sleep normally?
G.C.: I don't know for Greeks, but detailed studies exist in the U.S. Sleep problems start after 35, due to increased brain sensitivity to stress. Stress prevents sleep. These biological traits form bell curves: most people are in the middle, some very sensitive, some unaffected. Modern Western lifestyles shift the curve left - making people more sensitive due to daily stress. One big parental mistake: allowing children to take smartphones and screens to bed. Kids sleep late and have poor sleep quality, due to blue light suppressing melatonin, and stimulation that prevents sleep. Sleep is disrupted, with frequent awakenings or absence of deep Delta waves.
D.D.: Statistically, how many people get this?
G.C.: Normal adults and children get deep sleep. Those who don't are chronically stressed, use phones in bed, or drink heavily at night.
D.D.: They sleep little and are fine?
G.C.: Leonardo da Vinci and Michelangelo slept very little - rare exceptional people. Most need 7-8 hours, myself included.
D.D.: What about sleeping pills? Are they allowed?
G.C.: Unfortunately, sleep pills are benzodiazepines, like Valium.
D.D.: There's also a herbal Valium, which does nothing.
G.C.: Yes, they don't do much. Placebo effect is strong - believing something helps can actually help. So, if something works for you, take it. Prescription anxiolytics work, but are addictive. If used nightly, you'll rely on them for life.
Scene 8: Excessive light has been linked to cardiovascular disease and cancers
D.D.: That's alarming.
G.C.: New studies show sleep deprivation impairs immunity and increases stress hormones like cortisol, raising cancer risk statistically.
Scene 9: "Giorgiadis has helped the National Health System (ESY) a lot"
D.D.: So, what is the new discovery we found now?
G.C.: There are two new things. Hippocrates spoke of sleep, diet, and exercise. Later, two more problems were added, which we modern scientists highlight. One is the 24-hour rhythm, called the circadian rhythm - from circa diem, "about a day." It is regulated mainly by light, by the sun. It is innate in our cells, in our DNA, and is about 24.4 hours. The 24-hour cycle corresponds to the Earth's rotation. 3-4 billion years ago, it was exactly 24.4 hours. Since Earth's rotation changed, we must synchronize with the sun - the synchronization is 24 hours.
D.D.: And if there's no sun? Does it matter?
G.C.: Not immediately; the rhythm lasts 3-4 days without sunlight. But long-term deprivation changes it. Completely blind people have huge sleep problems, as their sleep time constantly shifts, because their brain works on 24.4 hours, whereas ours, synchronized with the sun, works on 24 hours. Sunlight enters through the eye, regulating a hypothalamic nucleus, the suprachiasmatic nucleus, which coordinates the whole body. This is the fourth element added to Hippocrates' three. The fifth is stress management. These two were not mentioned by Hippocrates, as artificial light didn't exist then. People used candles, which didn't produce much light, so they slept early. Today, artificial light suppresses melatonin and keeps us awake. Previously, people - even the generation of my parents - slept early, woke early, and even napped at midday when the father came home.
D.D.: Is napping at midday useful?
G.C.: Absolutely. Very beneficial for the body, proven.
D.D.: How does Greece compare to America in Pediatrics and Endocrinology?
G.C.: We're good. I worked at Georgetown and keep in touch; we're very strong medically, and I'm proud of that. Not just Pediatrics and Endocrinology, but medicine in general. English people even come to Greece for better medical care.
D.D.: Is the Greek NHS improved now?
G.C.: Compared to the British system, yes - better. You can get appointments immediately and find highly trained doctors. I returned from the U.S. as a director of a pediatric clinic, and the clinic I found was equivalent or better than Georgetown's.
D.D.: That was the university hospital, not the regular one.
G.C.: We are in the ESY hospital. I saw it myself. It wasn't just the university hospital at Paedon.
D.D.: Politically, has Giorgiadis helped?
G.C.: In my opinion, yes, he has helped and does what he can. I've worked with many Health Ministers before. Previously, when I had an issue in the clinic and asked him to act, he did it. Others often said "yes, yes" and did nothing - I won't name names. Leadership requires people who make decisions and implement them. He never said "no" when I asked. Others often did nothing.
D.D.: All governments, including New Democracy?
G.C.: All of them, yes.
D.D.: Character matters, I always say.
G.C.: Above all, character. Do you want votes, or do you want to help the country? Being a minister or deputy gives you a unique chance to benefit your country and leave a legacy. Not everyone sees it that way. I could have stayed in the U.S., but I returned at 51.
Epilogue: "The more overweight, the higher the risk of cardiovascular disease and cancer"
D.D.: What research are you doing now?
G.C.: Less basic than in the U.S., where research was expensive. Here, resources are limited, equipment costs double, bureaucracy slows material procurement and studies. But clinical research here is better and cheaper than in the U.S. Currently, I study the effects of obesity and stress in humans.
D.D.: Isn't obesity a mortality factor?
G.C.: Yes. Beyond diet and lack of exercise, chronic stress is a major cause of obesity. I was among the first to discover and publish this.
D.D.: What risk does an overweight person have?
G.C.: The more overweight you are, the higher the risk for cardiovascular disease, cancer, allergies, autoimmune conditions. Everything worsens with obesity.
The secretary, Ms. Eleni, opened the door. I had to leave. As I was leaving, I asked him:
D.D.: What is your dream?
G.C.: My dream is to build a country with good medicine, good health, and to raise children from an early age to become good, healthy citizens - physically and mentally.
D.D.: Parents shape the children.
G.C.: Parents, and subsequently, since mothers work, also kindergartens. We "park" children in our country. Children don't want to be parked; they want education - not school knowledge, but education in judgment, social skills, and more.
Do you hear this? It goes in one ear and out the other. Giorgos Chrousos' dream is mine too. What a person!