What are telomeres and telomerase – and why are they important?

What are Telomeres?

Telomeres are protective structures at the ends of our chromosomes. They consist of many repeats of a specific DNA sequence and proteins bound to it. Their job is to protect the chromosome ends from degradation and from the cell misrecognizing them as damaged DNA.

With each cell division, telomeres can become shorter in many cell types. This is due, among other things, to the fact that DNA replication cannot completely copy the extreme ends of linear chromosomes. If telomeres reach a critical length or other cell stress signals arise, a cell can enter a state in which it no longer divides.

Telomere length is therefore being investigated in research as a possible marker of cellular aging processes. However, it is not a sole or precise measure of a person's biological age: telomere length differs between people and cell types and is influenced by genetic, health and environmental factors.

Nutrition and telomere length

There is evidence that dietary habits may be linked to telomere length. For example, in observational studies, diets high in fruits, vegetables, and antioxidant nutrients, as well as Mediterranean dietary patterns, have been more frequently associated with longer telomeres. Possible explanations discussed include lower oxidative stress and more favorable regulation of inflammatory processes.

Foods that are useful as part of a balanced diet include:

• Berries and other fruits: They provide polyphenols and other antioxidant plant substances.
• Green leafy vegetables: It contains, among other things, folate, vitamin C and other micronutrients.
• Nuts and seeds: They provide unsaturated fatty acids, vitamin E and minerals.
• Whole grain products and legumes: They contribute to the supply of fiber and various micronutrients.

The classification is important: It has not been proven that individual foods specifically lengthen telomeres. Much of the research to date is based on observational studies. From this we can derive connections, but not clear cause-effect relationships.

What is Telomerase?

Telomerase is an enzyme complex that can lengthen telomeres or compensate for their shortening. To do this, it uses its own RNA component as a template and adds suitable DNA repeat sequences to the end of the chromosome. The telomerase RNA is not simply an RNA sequence that is added to the DNA, but rather serves as a blueprint for the extension of the telomeric DNA.

Telomerase is particularly active in germ cells, certain stem cell populations, and some other cell types. In most mature body cells, however, their activity is low or not sufficient to permanently maintain the telomeres. Many cancer cells reactivate telomerase or use alternative mechanisms to maintain their telomeres. This allows them to divide more often. This makes telomerase an important research area in cancer biology.

Can lifestyle and exercise affect telomeres?

Physical activity, a balanced diet, not smoking, adequate sleep and good management of chronic stress are examined in studies with various markers of health and cellular aging. Some research finds connections between a healthier lifestyle, telomerase activity and telomere length. However, the results are not uniform: the findings vary depending on the study design, the group of people examined and the measurement method.

A systematic review of nutrition, for example, found evidence of connections between fruit and vegetable consumption or Mediterranean dietary patterns and longer telomeres. At the same time, the authors emphasize that many of the included studies were observational and further high-quality intervention studies are needed. Research on exercise also shows interesting results, but does not guarantee that a particular form of training will lengthen an individual's telomeres.

Therefore, it makes sense to view exercise and a nutrient-rich diet as part of an overall health-promoting lifestyle - not as a targeted method to lengthen telomeres or halt aging.

Dietary supplements and telomerase

Some dietary supplements and plant extracts are advertised with the promise of increasing telomerase activity or lengthening telomeres. These include vitamin D, omega-3 fatty acids, resveratrol, curcumin and extracts from astragalus and schisandra.

However, most of these preparations have not been sufficiently proven to lengthen telomeres in healthy people in a clinically relevant and long-term beneficial manner. Results from laboratory or animal studies cannot easily be transferred to humans. Supplementation should therefore not be started solely with the aim of activating telomerase. If you have specific questions about dietary supplements, individual advice is useful.

Telomerase and cancer: Why more is not automatically better

Telomerase is neither fundamentally a good nor a bad enzyme. Their activity is important for certain cell types because it enables telomere maintenance. At the same time, many cancer cells use telomerase to maintain their ability to divide. A blanket increase in telomerase activity would therefore not be a safe anti-aging goal.

Research is therefore investigating both the importance of telomerase for normal tissue renewal and ways to therapeutically influence its activity in cancer cells. The decisive factor is the respective cell type and biological context.

Conclusion

Telomeres protect the ends of our chromosomes, and telomerase helps certain cells maintain these protective structures. Both play important roles in cell division, genome stability, aging processes and cancer biology.

A balanced, plant-based diet and regular exercise are recommended for many health reasons. Previous research suggests that such lifestyle factors may also be related to telomere health. However, it would be an exaggeration to present any single food or supplement as a proven method for lengthening telomeres. It makes more sense to focus on long-term health-promoting habits.

Sources

• Wu, R. A., Upton, H. E., Vogan, J. M., & Collins, K. (2017). Telomerase mechanism of telomere synthesis. Annual Review of Biochemistry, 86, 439–460. https://doi.org/10.1146/annurev-biochem-061516-045019
• Góngora, A.E., et al. (2019). Impact of nutrition on telomere health: Systematic review of observational cohort studies and randomized clinical trials. Advances in Nutrition. https://doi.org/10.1093/advances/nmz107
• Valente, E.A., et al. (2021). Effect of physical activity and exercise on telomere length: Systematic review with meta-analysis. Journal of the American Geriatrics Society. https://doi.org/10.1111/jgs.17334
• Shay, J. W., & Wright, W. E. (2002). Telomerase: A target for cancer therapeutics. Cancer Cell, 2(4), 257-265. https://doi.org/10.1016/S1535-6108(02)00158-7
• Kim, J. H., Ko, J. H., Lee, D. C., Lim, I., & Bang, H. (2012). Habitual physical exercise and circulating leukocyte telomere length in aging adults: A randomized controlled trial. Journal of Gerontology: Series A, 67(11), 1166–1173. https://doi.org/10.1093/gerona/gls068