How old are your organs?

Dilara Devranoğlu - Expert Molecular Biologist/Dietitian - @dilaradevranoglu

Our real age is no longer told by our date of birth, but by our cells: We may feel young. But what if our organs are different ages? As a result of scientific studies, we now know that our cells and organs do not age at the same rate. The aging process is not just a number on the calendar; it is a biological process that begins at the cellular level, affects the organs, and is eventually felt throughout our entire body.

KNOWING SENESENS IS THE FIRST CONDITION TO TURN BACK TIME

Many factors such as oxidative stress, DNA damage, telomere shortening, exposure to radiation and toxins due to environmental conditions and our diet cause the metabolic order of our cells to deteriorate. As a result, the cell's control and damage repair mechanisms are activated, and the damaged cell division is stopped and the repair process begins. If the damage in the cell cannot be repaired, cell division is completely stopped. The permanent cessation of cell division is called cellular senescence. Senescence is a mechanism that stops tumor development.

When senescence is activated in a cell, the cell cycle stops and the repair capacity of that tissue decreases. However, these old cells do not die, they remain in our body and emit harmful molecules into their environment that initiate inflammation and are associated with cellular aging.

The secretion of these molecules causes a change in the environment in that organ. Those secretions affect the surrounding cells and cause significant effects in our body and accelerate aging in a chain reaction. The accumulation of this damage in the body can accelerate the formation of age-related diseases.

Senescence is, in a sense, a "silent sabotage" that occurs at the cellular level. It used to be thought that these cells remained inactive, but we now know that they not only accelerate aging but also trigger some types of cancer.

CHRONOLOGICAL AGE, BIOLOGICAL AGE

Our chronological age may not reflect our biological state. Chronological age is the date of our birth. Biological age is a marker of how much our cells have “worn out.” Our biological age is determined by a combination of our genetics, epigenetic markers, diet, lifestyle, stress levels, sleep quality, and environmental factors. For example, two people may be 40 years old, but one may be 35 and the other 55. This difference is directly related to how our organs function.

ARE ALL OF OUR ORGANS THE SAME AGE? NO.

The real age of our body can surprise us. Our organs may be younger or more tired than we think. Different organs age at different rates. These biological clock differences determine a person's health status, susceptibility to diseases and general aging rate. For example, the accumulation of senescent cells in our skin due to sunlight, air pollution and stress leads to loss of elasticity, wrinkles and dryness in the skin. The aging of microglia cells, which form the extensions of nerve cells in our brain and have a defense function by creating an immune response against dangers such as bacteria, viruses and toxins, cleaning dead cells and leftover proteins, and repairing damaged nerve tissues; leads to inflammation of our nervous system and cognitive decline, and increases our risk of developing Alzheimer's in old age. Our liver has a high regenerative capacity, but it can age prematurely with excessive alcohol consumption, drug use and fat. The cells in our heart and veins harden as we age, lose their elasticity and pave the way for hypertension and heart diseases. As our bone and muscle cells age, bone density decreases and muscle loss occurs. As we age, the flora in our intestinal cells and microbiota changes, absorption deteriorates, and our immunity weakens.

Our aging cells in our organs don’t just stop working; they also damage our bodies. Senescent cells increase the effects of age-related diseases such as cancer, Alzheimer’s, diabetes, and osteoporosis on a person. It is known from research that some of our organs, such as our skin and immune system, age earlier on average, and some of our organs, such as our liver, are more resistant.

Experts have begun to express the opinion that some patients' cardiovascular age may be 70 years old, but their liver functions may remain at 50 years old, and that organ age differences necessitate a personalized approach in treatment processes.

HOW DO WE MEASURE THE AGE OF OUR CELLS? THE EPIGENETIC CLOCK.

Thanks to advances in genetics, biological age can now be determined by looking at chemical changes called methylation on our DNA. This is called the epigenetic clock. In these tests, methylation profiles are extracted from saliva or blood samples using DNA analysis to determine a person's biological age and aging rate. The data obtained can be compared with bioinformatics models and the estimated biological age of organs such as the heart and brain can be determined with artificial intelligence-supported imaging techniques.

IS IT POSSIBLE TO KEEP OUR CELLS YOUNG?

It is possible to slow down aging with healthy lifestyle habits that we will change in our lives; first and foremost, a Mediterranean type anti-inflammatory diet where we consume olive oil, green leafy vegetables and seafood containing plenty of omega-3 fatty acids; calorie restriction, which is associated with longevity and affects aging genes; supporting cell renewal; regular physical activity and adequate sleep; stress management with psychotherapy, meditation, breathing exercises and contact with nature against chronic stress that increases cortisol secretion that accelerates senescence; and finally, senolytic drugs that target and destroy old cells and have been shown to increase lifespan and quality of health in animal studies, the names of which we will soon hear much more about.

Senolytic drugs are new treatments at the cellular level that selectively target and destroy senescent cells in the body, potentially delaying aging. The aim of these drugs is to support healthy aging by eliminating senescent cells that accumulate with age and damage tissues. These drugs target the defense mechanisms that allow senescent cells to survive, destroying only senescent cells, and work without significantly affecting healthy cells.

In studies investigating senolytic treatments, these drugs have been shown to increase muscle function in experimental animals, preserve vascular elasticity, delay osteoporosis, improve cognitive functions, and cleanse senescent cells and extend life span. Some of these molecules are fisetin and quercetin, a natural flavonoid found in fruits such as strawberries and apples. Clinical studies of senolytic drugs on humans are promising but limited. Studies have shown that inflammation has decreased and physical functions have improved in elderly individuals. However, their long-term safety and effectiveness are not yet fully known, and no senolytic drug has yet entered widespread clinical use.

WHAT WILL HAPPEN IN THE FUTURE?

Scientists now see aging not only as a "natural process" but also as a "preventable biological process." Some researchers even debate classifying aging as a disease, because it is emphasized that slowing down aging can also delay the chronic diseases that accompany it, and that the body's biological clock can be slowed down by adopting correct lifestyle habits.

Today, we use personalized functional nutrition and lifestyle recommendations, senolytic treatments and stem cell applications supported by genetic, epigenetic analyses and intestinal microbiota analyses as the most powerful tools to keep our organs young.

We now know that it is not just the year we were born that shows our age. What really matters is how healthy our cells remain and our lifestyle. Taking good care of our cells is the biggest factor that determines how old we will feel and can delay the aging of our organs. The care we show our body is the biggest investment we make in our future.

Take care of your cells. In good health!