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2022 Neuropsychological Effects of COVID-19 in Older Adults from Health Disparity Populations (NAN)

COVID-19 Infection Effects in Older Adults Associated to Health Disparities

How does COVID-19 impact chemical changes to DNA in older adults, and how do these changes influence health outcomes?

Paola Garcia, Ph.D.
Mexican Institute of Social Security
Ciudad de México, Mexico


A major focus of Alzheimer’s disease research is to identify genetic factors that may impact a person’s risk of developing the disease. In addition to examining specific genes that increase risk, researchers are also studying other types of unique genetic information. The epigenome, for example, is a record of chemical modifications that can turn genes “on” or “off” in response to their environment or disease state. This chemical modification of genetic material (DNA) is known as epigenetics.

One way in which DNA is modified is by the addition of a chemical methyl group, a process called DNA methylation. Methylation is used to turn genes "on" or "off" during different phases of the body's development, and it helps regulate proper gene expression (the conversion of genes into proteins). DNA methylation may be involved in many normal brain processes, including learning and memory, and the process may become altered in Alzheimer's and other dementia.

Studies show that the patterns of DNA methylation in individuals can be associated with aging and mortality. So-called “epigenetic clocks,” which measure the chemical changes that take place in DNA over time (“epigenetic aging”), have been shown to potentially be more accurate biological markers (biomarkers) of aging than chronological age. Epigenetic clock analyses show that COVID-19 infection is also associated with increased DNA damage, increased epigenetic age, and elevated mortality risk. More research is needed to understand how COVID-19 infection impacts epigenetic mechanisms, including DNA methylation, in older adults.

Research Plan

Dr. Paola Garcia de la Torre and colleagues will study how COVID-19 infections impact DNA methylation and DNA damage in a sample of older adults from Mexico City and investigate whether these changes are associated with socioeconomic level, psychosocial status, or cognitive functioning. The researchers will study 1,678 older adults who have been part of the Cohort of Obesity, Sarcopenia, and Frailty of Older Mexican Adults (COSFOMA) study. First, Dr. Garcia de la Torre and team will characterize the impact of COVID-19 on cognition, anxiety and depression in these individuals. Then, using blood samples from the participants, they will measure the impact of COVID-19 on DNA methylation patterns and DNA damage (epigenetic age estimation).


The results of this project may shed new light on the underlying biology related to cognitive decline. The findings may provide insights into the effects of COVID-19 infection on epigenetic aging, DNA damage, and changes in cognition, function and behavior of individuals.

The NeuroCOVID Grant Program was developed jointly with the Alzheimer's Association and the National Academy of Neuropsychology.

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