What is Cellular Ageing?
Cells in the human body undergo a process known as senescence, often called cellular ageing. Cellular ageing is a natural and complex process influenced by genetics, the environment, and lifestyle choices. It involves several key elements:-
- Telomeres: Telomeres are protective caps at the ends of chromosomes. With each cell division, telomeres shorten, and once they become critically short, cell division may cease, and cells can become senescent or die.
- DNA Damage: Over time, the DNA within cells can accumulate damage from factors like exposure to radiation, toxins, and free radicals. This damage can lead to DNA replication and ‘transcription’ errors, contributing to cellular ageing.
- Mitochondrial Dysfunction: Mitochondria are the energy-producing organelles in cells. As they become less efficient with age, cells may generate increased levels of oxidative stress, which can accelerate cellular ageing.
- Cellular Senescence: Senescent cells have lost their ability to divide and function properly. They can accumulate in various tissues and contribute to ageing and age-related diseases.
While cellular ageing is a natural part of life, it’s not uniform across all cell types. Some cells, such as stem cells, have mechanisms to maintain their ability to divide and replace damaged cells. However, other cell types, like neurons and cardiac cells, have limited regenerative capacity, and their ageing is more pronounced.
Lifestyle choices, such as diet, exercise, and managing stress, can influence the rate at which cells age. For example, a healthy lifestyle can help reduce oxidative stress and DNA damage, potentially slowing down the ageing process at the cellular level.
It’s important to note that there is ongoing research in cellular ageing and strategies to slow or reverse this process (especially at Harvard Medical School, under Genetics Professor David A. Sinclair). Slowing down the rate of cellular ageing can contribute to healthier and longer lives.
(See: https://www.hms.harvard.edu/agingresearch/index.php/sinclair ).