One thing we all share is that as we grow older our bodies change, and some of these changes increase the potential for decline, illness, and disease. Although life expectancy has increased significantly over the past century, our healthspan has not been increasing to the same extent as our lifespan.1 Our healthspan is simply the portion of life where good health is enjoyed.
Understanding the complex reasons for why and how we age has been a significant challenge for aging researchers. The popular and well-supported Hallmarks of Aging paper, written in 2013, proposed nine interconnected reasons why we age.2
Identifying these nine hallmarks gives us incredible insight into what damages our cells as we age. And, it’s now widely recognized that the underlying process of aging actually is the accumulation of cellular damage over time.3
The build-up of cellular damage is believed to be a major factor driving the functional declines we experience as we age. And the hallmarks of aging help to explain how these different types of cellular damage affect the way we age.
One of the main hallmarks of aging is damage to our DNA, known as genomic instability. Our genome is made up of DNA, which contains all of the genetic information that makes us who we are. Gradual damage to our DNA and faulty repair mechanisms allow errors to pass through and cellular damage to buildup over time. So, genomic instability is the result of the accumulation of genetic damage over the course of our lives.2
Damage to our DNA is a significant contributor to the other hallmarks of aging as well. For example, telomere shortening, mitochondrial DNA damage, and mitochondrial dysfunction are all related to cellular DNA damage.2
Throughout our lives, our cells are constantly exposed to both internal and external factors that cause cellular damage. It’s the accumulation of cellular damage that ultimately leads to age-related conditions and accelerated aging.4
There are many ways cells can become damaged. For example, the natural process of producing cellular energy (ATP) creates oxidative stress each day, which can lead to the buildup of free radicals and toxic waste in our cells. A small amount of oxidative stress is necessary and beneficial to help fight off pathogens. However, when free radicals are no longer balanced by cellular antioxidants, damage occurs as a result. Inflammation is another culprit contributing to cellular damage and has far-reaching negative effects when it becomes chronic. There are also environmental and lifestyle factors including ultraviolet rays, cigarette smoke, alcohol use, poor diet, and pollution that contribute to the accumulation of cellular damage over time.5 Together, these factors negatively affect our cells and eventually cause changes to their structure and function. These cellular changes can have a significant impact on the way we age. The constant exposure to these stressors causes damage to the lipids (fats), proteins, and DNA within our cells.
Together, these factors negatively affect our cells and eventually cause changes to their structure and function. These cellular changes can have a significant impact on the way we age. The constant exposure to these stressors causes damage to the lipids (fats), proteins, and DNA within our cells.
Healthy cellular functioning depends on processes such as DNA repair, natural cellular detox, and quality control mechanisms such as autophagy. However, when these repair processes become faulty, cellular damage continues to accumulate and eventually damages our tissues and organs, affecting their performance.4The more we understand these underlying processes of aging, the more feasible it becomes to develop targeted solutions at the cellular level. After all, the goal isn’t just to add years to our lives. The goal is to spend those extra years in good health with the energy and vitality needed to enjoy them.