An excerpt from The Spine Encyclopedia: Everything You’ve Wanted to Know about Back and Neck Pain but Were Too Afraid to Ask.
As we age, our cells become less functional, and bodily tissues lose the ability to replenish and regenerate. The spine is not excluded from this process and undergoes predictable degeneration as we age. For some, spinal degeneration turns into serious pain and disability that can end in the need for surgery. For others, this is not the case, and they continue to have active lifestyles despite degeneration in the back and neck. What separates these groups? What can we do to make sure our backs work for us as opposed to having to work for our backs (going to the doctors, getting treatments and surgery)? While the answers to these questions remain somewhat unknown, there are many non-surgical interventions to not only extend the life span of our spines, but also of our lives. These include practices such as following a healthy, low-calorie diet, not smoking, treating osteoporosis, and practicing a balanced exercise regimen.
Mr. Silver is a healthy 70-year-old male. He retired from a career as a teacher at the age of 65 and has been very busy in retirement. He pays close attention to his health and makes sure he does at least 40-50 minutes of vigorous exercise 4-5 times a week. This can consist of a brisk hike, bicycle riding, or even swimming, and he enjoys switching between these activities. He used to be an avid runner but finds hiking, biking, and swimming to be more tolerable to his bones and joints these days. He participates in yoga, and to outside viewers, his posture, gait, and flexibility reflect that of a young man, although he will tell you he feels stiff at times. He has never smoked and only occasionally drinks wine. In addition to these basic tenets of lifestyle, he is very active with his grandkids and enjoys a full circle of friends with whom he regularly socializes. Although he can drive himself to the doctors, he is never short of volunteers who want to come with him for support. He has no pain, has not had a fracture from weakened bones, and takes no medicines.
Getting older is inevitable. The turn of the century Italian philosopher Giacomo Leopardi had this to say about aging: “Old age is the supreme evil because it deprives us of all pleasures, leaving us only the appetite for them, and it brings with it all sufferings. Nevertheless, we fear death, and we desire old age.” We all want to continue living, but the price for continued life is getting older, including an aging skeleton. Unfortunately, aches and pains are going to be in everyone’s future, but as a physician, I have noticed that there seems to be a trick to aging gracefully. Looking at colleagues and patients, I have seen those who “cruise” into old age and those who “bruise” into old age. In other words, some have no issues in old age, and others have endless problems. While genetics likely play a crucial role in aging, we cannot control our genes (yet). However, we do have the power to change environmental factors and lifestyle choices that accelerate aging. In medicine, we talk about a patient’s genotype and phenotype. The genotype simply refers to the type of genes a person has (for example, a person has a gene for brown hair), while the phenotype refers to the actual expression of those genes (that is, a person has brown hair). Our environment plays a role in determining the phenotype as expressed with this equation:
Phenotype = Genotype + (diet and lifestyle).
The phenotype we all want is one that allows us to live a long, healthy life. We must assume we are stuck with our genotype, but this equation begs the question: what are the things we can do to age gracefully?
What is aging and why does it happen?
Aging is simply the process of becoming older. Superficially, as we age, we appear to have more wrinkles and blemishes in the skin, and perhaps grayer 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 arising 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 end 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 aging 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 decreases (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 is an orthopedic surgeon and author of The Spine Encyclopedia: Everything You’ve Wanted to Know about Back and Neck Pain but Were Too Afraid to Ask.