Want to slow down aging? Try these lifestyle habits

Text and figures by Ayesha Lobo

The average human lifespan has significantly increased over time thanks to advancements in modern medicine. Still, many scientists are working to understand the biological mechanisms of aging to develop interventions that improve lifespan. Some researchers have focused on a particular change that occurs in our DNA as we age, known as “telomere shortening,” and how lifestyle factors have the potential to help slow down or even reverse this process – which essentially slows aging and increases lifespan.

What is a telomere?

DNA is the biological library that contains our hereditary information in the form of genes. When genes are damaged, it can lead to severe consequences, such as cancers and other diseases. Because of this, the integrity of genes is critical to ensure proper cellular function. One way that our bodies protect DNA is with telomeres. Telomeres are the end sequences of our DNA, and they act like cellular shields that protect genes from degradation.

Imagine DNA like a shoelace – telomeres would be the aglets at each end, protecting our genes from being degraded by external forces. Over time, these protective telomeres naturally shorten, which increases the risk of genes being damaged.

Telomere shortening is associated with aging

Over the course of our lifetimes, our cells will make copies of themselves through a process known as cell division. For a cell to properly divide, its DNA must be replicated. Every time a cell divides, however, the length of its telomeres shortens (Figure 1). Because cell division occurs many times over the course of a lifetime, telomeres will continue to get shorter and shorter as we age, thus decreasing DNA’s protection. The speed at which telomeres shorten is influenced by a variety of factors, including age, genetics, environment, socioeconomic status, and lifestyle factors. For example, proper nutrition and exercise can reduce the pace of shortening. However, diseases such as obesity or chronic stress can negatively impact telomere length. Let’s begin by exploring how obesity and stress can impact telomere shortening.

**Figure 1: Telomeres shorten with each DNA replication.** DNA is the genetic material that encodes for your genes (yellow). Telomeres (blue) are the sequences of DNA at the ends of these DNA strands that protect your genes.

Obesity increases the pace of telomere shortening

Obesity, a disease characterized by high levels of fat tissue, is linked to accelerated aging. Interestingly, scientists have found that fat tissue contains high levels of unstable molecules called reactive oxygen species (ROS). ROS are highly reactive, and can break telomeres (Figure 2). A particular study found a statistically significant increase in the rate of telomere shortening among obese women. The researchers determined that the difference in telomere length shortening between healthy and obese individuals correlated to approximately 8.8 years of aging. They hypothesized that this result could be partially due to increased levels of ROS harming DNA. Therefore, it is vital that individuals suffering from obesity are given proper access to care and resources to mitigate the health impacts of the disease, particularly as it relates to telomere shortening and aging.

**Figure 2: Reactive oxygen species can damage DNA.** Reactive oxygen species are small, unstable molecules that can damage DNA.

Nutritional choices may slow the pace of telomere shortening

Studies have found that diets rich in fibers, fruits, legumes, vegetables, and nuts are linked to longer telomeres. These foods contain antioxidants and vitamins that help protect DNA from damage. As mentioned previously, reactive oxygen species are small unstable molecules that can damage DNA. Thankfully, antioxidants can serve as a DNA protector by neutralizing ROS. The body produces some antioxidants on its own, but relies on external consumption of antioxidants to increase DNA safety from ROS. Therefore, diet is important in reducing the pace of aging by protecting telomeres from DNA damage.

Chronic stress may result in shorter telomeres

The physical impacts of stress are often evident, and aging is no exception. Stress is associated with the release of glucocorticoid hormones, which help the body react to challenging situations and environments. While these hormones are necessary for managing stress reactions, an excessive quantity can cause telomere shortening. These hormones have been shown to decrease the number of antioxidants available to protect DNA from damage. Stress, therefore, may make DNA more vulnerable to telomere shortening, increasing the pace of aging. In one study, women under consistent stress had telomere lengths equivalent to those of women 10 years older. Therefore, effective stress management is critical to ensure quality of life and longevity from an aging perspective.

Exercise may help maintain telomere length

Exercise has been shown to improve many aspects of physical well-being, such as better bone and heart health, emotional well-being, and muscle gain. Additionally, exercise may help slow the pace of aging by protecting telomeres from damage — and by helping rebuild telomeres that have shortened (Figure 3). Even though telomeres shorten with each cell division, cells use a protein, known as telomerase, to rebuild these sequences. Studies have demonstrated that exercise increases the activity of telomerase, rebuilding the length of telomeres after they have shortened. Therefore, consistent exercise may help slow the pace of aging, and protect against age-related chronic diseases.

**Figure 3: Telomerase extends shortened telomeres.** Telomerase (green) is a protein that extends telomeres to increase telomere length.

The impacts of short telomeres, and how you can maintain long telomeres

Short telomeres are associated with an increased risk of cancer, heart disease, premature aging, and mortality. Though this is a natural process that occurs in all humans, there are methods that can help slow the pace of telomere shortening, helping individuals live longer and healthier lives. Frequent exercise and diets rich in antioxidants, vegetables, fruits, fibers, nuts, and whole grains can help maintain telomere length. However, some vital factors contributing to telomere shortening are exacerbated by inequitable access to health care. Though not all factors that contribute to telomere length are within our control, there are various aspects of daily life that can significantly improve the maintenance of telomere length, and increase lifespan and overall well-being.

Ayesha Lobo is a master’s student in Media, Medicine, and Health at Harvard Medical School.

Cover image by sabinevanerp on PixaBay.

For More Information:

For a quick article on how antioxidants neutralize reactive oxygen species, click here.

To learn more about how exercise can help rebuild telomeres, read this.
To learn about which specific dietary micronutrients positively impact telomere length, scroll to table 2 in this systematic review.