Have you ever met someone and thought, wow, that person looks 10 years younger – or 10 years older – than his or her actual age?
That’s because aging depends on more than just your chronological age. It’s also about your biological age, or your rate of cellular aging.
Your biological age could be quite different from your chronological age. This is because your biological age can speed up or slow down, depending on biological and environmental events in your life.
But how can you tell how old you are, biologically?
The clues to your biological age may be revealed by your telomeres. Telomeres are a tiny cap on the tip of your DNA strands. The length of your telomeres reveals your biological age. As your cells divide over your lifetime, the telomeres shorten.
For example, babies have longer telomeres than young adults, who in turn have longer telomeres than older adults. But not all adults of the same age have the same length of telomeres. People of the same age can have a large range of telomere lengths. That’s because people differ in their rate of actual cell aging. Researchers believe that telomeres hold the biological keys to decelerating aging and increasing lifespan.
But here’s the bad news. Telomeres may be susceptible to environmental factors.
Telomeres can be shortened by oxidative stress and inflammation – biological processes that can damage DNA. Smoking, diets high in sugar and saturated fats, lack of exercise, and insufficient sleep all accelerate aging at the cellular level, and shorten telomeres.
Emerging research suggests that short telomeres may be a marker for cognitive decline and that those with longer telomeres remain cognitively sharper over time. Although telomeres can’t yet reliably tell us who might develop a dementing condition like Alzheimer’s disease, there’s some convincing evidence that short telomeres are a significant risk factor for dementia, particularly in women 65 and over.
Lastly, stress may be a strong predictor of telomere length. Different kinds of stress all appear to shorten telomeres, including chronic stress, social stress, and social isolation. Even mild but unpredictable stress has been shown to increase anxiety and negative mood, which reduces telomere length and increases brain aging.
But here’s the great news. Telomeres can be restored by an enzyme researchers think may be produced when you exercise regularly. The same beneficial effect may also occur with sufficient sleep, managing your stress, and eating a mostly plant-based diet high in antioxidants.
Although there aren’t any tests yet available to measure your telomere length, understanding how telomeres affect aging is key to realizing that aging isn’t a passive process. Instead, telomeres show us that aging may well rest in our own hands.