Do You Feel Like Age is Catching Up With You?

Although we typically think of the external signs of aging with the emergence of wrinkles and graying hair, aging is also an internal process that has roots at the cellular level. All the organs of our bodies are made up of individual cells that have limited life spans. While we are young, our cells divide many times as we grow. Our cells are capable of repairing themselves, communicating with other cells, and interacting with all the physiological molecules that ultimately define our current state of health. Scientists have discovered, however, that our cells have a limited capacity to divide and repair.

Laboratory studies have shown that cell aging patterns are genetically encoded and cell death occurs along a predictable schedule of events for different cell types. Our DNA is bundled into chromosomes, each capped with repeated sequences called telomeres. During cell division, the cell attempts to make a complete copy of itself, including all of its DNA, but researchers have discovered that these telomeres shorten over successive cell divisions. The telomeres help protect the DNA from radical arrangements (that might cause cancer, for example) and they can be lengthened by an enzyme called telomerase. If the telomeres are allowed to become too short, however, the cell senses this problem and puts in motion a cascade of events that will result in its own death. This mechanism of programmed cell death, also called apoptosis, is a critical part of proper human development and a natural part of the life cycle of a cell.

A cell’s life also comes to a close if its DNA sustains damage more quickly than the DNA repair machinery can compensate for it. One of the major causes of DNA damage in our cells is the presence of free radicals. These highly reactive molecules can cause significant damage to both the proteins and the DNA in our cells by undergoing chemical reactions with them. The free radical theory of aging suggests that these molecules accumulate naturally over time and that our DNA repair machinery copes less and less well with the damage. Thus, our physical aging would be correlated with this decline in the health of our individual cells. Free radical damage has also been scientifically linked to many age-related medical conditions, including arthritis, Alzheimer’s, heart disease, diabetes, and cancer. Intriguingly, it has been shown that antioxidants can slow or stop the damage caused by free radicals by helping to balance the chemical reactions in the cells. Antioxidant levels can be increased by adding antioxidant rich foods to the diet or by taking nutritional supplements.

Because our cells become less resilient as we age, so do our bodies. We become more susceptible to illnesses and once we get sick, it takes longer to recover. Wounds may also take longer to heal. As some cells begin to lose function, they cease expressing hormones, further shifting our physiological balance. All of the changes to our immunity, metabolism, and body chemistry can have a huge impact on our health and well-being as we age.