Brain excercise / Genetics / longevity

I am Age Fluid

Age is just a number

We all have a chronological age based on the day we were born. It tells us how long we have been alive, which is essential information. For instance, I was born in January 1945 during WWII. I remember such things as President Eisenhower, the Cold War (duck and cover), the introduction of color television, the princess phone, 78 RPM records, typewriters, and cars without seat belts. So knowing my chronological age provides information about my life experiences. But does it say how old I am?

The answer is no because we do not all age at the same rate. Even different parts of our bodies can age at different speeds. That means we could have an old heart and a young brain or vice versa. Even parts of our brains age at different rates, as I have learned in a recent experiment using AI and MRI to determine the age of various aspects of my brain.

Longevity and Health Span

Health Span and Life Span are different but related concepts. Health Span has to do with the quality of your health, whereas Life Span is the length of the actual years you will be alive. It is possible to have an excellent health span living all your life without being ill and dying from a sudden cardiac event. It is possible to live well into your 90s after suffering from arthritis for thirty years. I believe that health span currently can be improved primarily through lifestyle. Longevity can also be enhanced by lifestyle, but depending on what will kill you eventually, it may have no impact. For instance, you could take statins to reduce your LDL significantly only to die of lung cancer. Smoking is a lifestyle decision that affects longevity—a lot of confusion results from looking at averages. If you reduce obesity, you will increase your life span because some people will die due to diseases related to their being overweight.  

For the last year, I have been advising Sheba Hospital, Israel’s most prominent medical institution (actually the largest hospital in the middle east and one of the top ten hospitals in the world), in developing one of the world’s first Longevity Center associated with an academic institute. This allows me to work alongside the Center’s two amazing leaders, Dr. Tzipi Strauss and Dr. Evelyne Yehudit Bischof, and to collaborate with Abigail Goshen, the Chief Scientist.

I unsuccessfully lobbied to use the “Health Span Center” because that is what I think we will do. However, knowing if we increase the life span will not be possible. It will take too many years to determine that. Therefore, my motto is “Living Better Longer,” not just “Living Longer.” 

As some of you will know (especially those that read my book, The Flight of a Wild Duck, my first career was in medical science, having started neurology and then cardio/pulmonary medicine. I was an associate professor in that field before I was thirty. I have circled back to my interest in medical science during the last ten years. Given my chronological age, longevity and particular health span (the number of healthy years we have left) became an interest, as well as the potential to use AI for personalized medicine.

My involvement with Sheba allowed me to learn about the science of longevity. Along the way, I came across the term biological age. Biological age is a much more complex concept than chronological age. Our biological age is primarily the result of our genetics and lifestyle. It can indicate the number of years we still have ahead of us and the current functioning of our body, including our cognitive abilities. As I said earlier, not every part of us ages at the same rate. So while you might be ten years younger than your chronological age, it does not mean you will live ten years longer than your chronological age indicates. But perhaps even more important is how old you feel.

We all see the variability of health related to age. For example, we may know people who are 85 years old who are still very active and still working, while we know others in their 60s who have difficulty getting off the couch.

Biological Clocks and Longevity

Longevity Scientists have been developing methods to characterize biological age. They have created calculators that can indicate biological age. They use markers which they call “clocks.” One of the techniques used is to compare these markers to an extensive database of people to find the age of people with similar numbers. These markers can be related to blood analysis, weight, lifestyle, genetics, etc. I have used many of these calculators myself. The results can vary greatly. I am not a strong proponent of these calculators, but they are a start. I don’t think they can determine your biological age in the sense that they can be used to estimate when you will die. While it is interesting and perhaps necessary to know your biological age (it might help in retirement planning), it can be most helpful in helping improve health quality. However, it is the taking of action that can result in an increased health span and even an increased life span. For instance, changing your diet, exercising more, and doing brain exercises can result in significant benefits. I think we are at the very early stage of all of this. I am excited that I can contribute to this field through my work at Sheba. At the Sheba Longevity Center, we will focus on Sleep, Frailty, Cognitive Function, and Hormonal Issues for women. 


I have been struggling with my age physiologically. Sometimes I wonder if I still have a purpose and can remain relevant. I worry that I will become ill as I get older. These considerations and not my actual experiences inform my attitude about age. I am healthy, and I am still relevant. I realize that I, myself, am practicing self-agism. Thankfully, I live in Israel, where ageism is not prevalent. I can have friends in their 20s, and I do. That helps a lot. Sometimes I joke that I like to hang out with my friends’ children because my friends are too old for me.

When I meet people I have not seen in many years, I am often shocked by how old they look. It can be very upsetting. Probably, they have the same reaction seeing me. After a while, I get over this. But more troubling is when it is more than looks. When they can not keep up with me when walking, have trouble remembering things when all they can do is talk about their illnesses and the medicine they are taking.

How old am I really

My chronological age is 78. Generally, people think I am about ten to fifteen years younger, likely due to a combination of how I look and how I act. I believe people are good at determining someone’s biological age just by interacting with them.

I have let my chronological age impact my thinking about my future. For instance, I have been reluctant to take on projects requiring many years to complete. The other day, after finishing a very strenuous pilates training, I felt like I was forty. I began asking myself, what would I do if I was 65 and not 78? Maybe using a number is not the right way to think about this. It is too binary. Perhaps some days I am older, and some days I am younger. I am age fluid.

I do find myself thinking about medical care. I have started to consider the quality of medical care when considering travel, even though the last time I had to go to a hospital was sixty years ago. I have decided not to let these concerns influence my travel plans. Fighting against the tendency to let the world close in is essential.  

Generally, I am fortunate to have picked the right parents. My father was almost 97 when he died. He went to the gym six days a week until he was 95 when his cognitive function began to decline, and he could no longer drive himself to the gym. My dad exercised his body but not his brain. I do both. Sadly, my mom died at 67 but took her own life. But longevity ran in her family, with my grandmother and great-grandmother living into their 90s. I also live a very healthy lifestyle, practice intermittent fasting, and have a low-carb diet. I exercise almost every day. I get a lot of sleep and have a fantastic relationship with my wife. Nevertheless, I need medication to keep my LDL low (now 52) and my blood pressure in a good range (115-75). My glucose and weight are normal

Longevity Escape Velocity

I should also mention that some people now think we can live forever. Immortality is likely possible, but I doubt it is relevant to anyone reading this post. My interest is living better longer. I don’t want to be an older man living in the memory care unit of a senior living facility. Since 1840, life expectancy has increased by three months every year. The majority of those born now will be alive to see their 100 birthday. Those who hope to live forever seek Longevity Escape Velocity: A time when the average longevity is increased by one year every year.  

Economic Impact

The USA spends about 20% of its GNP on Health Care. Almost 40% is spent on individuals 65 or older, even though they represent about 16% of the total population. Two-thirds of this happens in the last year of life. The economic impact of increased health span and life span is complex. For instance, would an increase in health span result in more productivity as people worked longer?

Age Fluidity

Society is chronological age oriented. That is because we have nothing else to go on, and on average, it probably works. But we would do well to develop a more flexible definition of age. For most of human history, people did not know their birthdates. They were as old as they appeared and as old as they felt. That was probably a good thing.

I have decided to have a much more expansive and comprehensive view of age. But I must change my attitude about age, particularly my age. For example, it may be that if you think you will live a long time, you will live a long time.

Some of the tools I use:

Oura Ring

Apple Watch


Heads Up Health

Libre Glucose Monitor

7 thoughts on “I am Age Fluid

  1. Hi Avram, thanks for the blog. I would like to make you aware of Optoceutics, a Danish company making products to combat dementia. More information at I am an investor so have an axe to grind. Let me know if you are interested. Best Regards, David


  2. Hi Avram,

    Found this article edifying. Definitely an interesting equilibrium of lifespan vs healthspan-a long lifespan with poor healthspan or short lifespan with rich healthspan is not what people want. Which has the makings of a complex, nonlinear, multivariate optimization problem.


    • I also love your points
      mentioned with your parents and the healthy habits / lifestyle choices made. I’m a large proponent of generational health. Creating a latticework of habits that positively compound. I look forward to your future posts.



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