WHAT IS AGEING AND WHY DOES IT HAPPEN?

Ageing is simply the process of becoming older. Superficially, as we age, we appear to have more wrinkles and blemishes in the skin, and perhaps greyer hair. We don’t have the same strength, endurance, and even body shape as we did when we were younger. But on a molecular and cellular level in the body, what is driving these changes?

Cells are the building blocks that form all our tissues. As we age, our cells age too. Stem cells, which are cells that are capable of becoming a range of different tissues (bone, muscle, blood, etc.), lose the capacity to undergo differentiation—the ability to change from one cell type to another. This is problematic because stem cells are responsible for replenishing damaged tissue, for example, damaged cartilage in joints. So, the body cannot regenerate as effectively.

Unlike the cells in young bodies, cells in the older person’s body also lose some of their metabolic capacity and start to accumulate waste proteins, resulting in malfunction. This is thought to occur because of several different reasons:

    DNA damage arises from exposure to free radicals (free radicals are high-energy molecules in the body capable of destroying or damaging other molecules).

    Shortening of telomeres (telomeres are structures on the ends of your DNA that protect it from degradation).

    Advanced glycosylation end products (AGEs) (destructive molecules created from sugar) abnormally bond with other normal proteins and fat molecules, and over time, these altered molecules accumulate.

    Our cells may be intrinsically programmed genetically to age and stop working.

Thus, the body loses its ability to replace old or damaged cells, and those older cells start to malfunction. This disrupts the complex biological processes in the body.

Cellular ageing processes affect the musculoskeletal system, and we know that three things happen:

    Bones lose density, becoming weaker and more brittle (aka osteoporosis and osteopenia).  Muscle mass and density decrease (a.k.a. sarcopenia)

    The smooth cartilage which covers our joints wears down. In the spine, all three of these processes occur in addition to degeneration of the intervertebral discs—the structures which are responsible for linking our vertebrae together. - Yoshihiro Katsuura