It is no secret that everyone ages. Humans do not stay frozen at a specific age. They age, and when they age there are declines in processes such as metabolism and cognition. A recent study investigated why there may be a loss of cognition with age. One answer is the length of the telomere!
Telomeres are DNA-protein complexes capping the chromosomal ends (see Figure). Telomeres shorten each time the cell divides and when they become too short, the cell will become damaged and die. The accumulation of cell damage due to telomere shortening is thought to be a major cause of the symptoms of aging. In the current study (1), telomere length was measured in 497 individuals. The individuals had their blood taken when they were young adults. They also completed tests to assess their cognitive function. Then 13 years later, these same individuals had their blood taken and were tested again. Using the blood samples, the experimenters extracted DNA from their white blood cells and measured the telomeres on their chromosomes. During the study, multiple factors were considered to account for variability between subjects, such as sex, ancestry and socioeconomic status. The study found that there was a connection between telomere length and global cognition that withstood all demographic factors measured by the study. Specifically, the greater the rate of shortening of the telomere, the worse the cognition. Aspects of cognition such as information processing speed, memory, and visual-spatial awareness all declined in relation to the shortening of the telomere. Previous studies made connections between the loss of cognition and age, but no studies have made the connection between shortening of the telomere and loss of cognition.
This study opens up the door to an efficient and simple method that could lead to early detection of cognitive decline in older adults. Everyone ages; there is no denying that fact of life, but this study has the potential to reduce the amount people suffer with age.
- Cohen-Manheim, I., Cohen-Manheim, I., Doniger, G. M., Doniger, G. M., Sinnreich, R., Sinnreich, R., . . . Kark, J. D. (2016). Increased attrition of leukocyte telomere length in young adults is associated with poorer cognitive function in midlife. European Journal of Epidemiology, 31(2), 147-157.
Department of Biology
University of Mississippi