Stress Effects Genetics

Stress affects individuals differently. Some people may experience intense stress during traffic jams while others see this as an opportunity to take their time and relax. So, do stress-related genes exist? Discover the latest findings on the genetics of stress, and whether the link between stress and genetics locks you into a specific level of stress tolerance.

Genetics of Stress: The Role of NPY

Research led by scientists at the National Institute on Alcohol Abuse and Alcoholism, a division of the National Institutes of Health (2008), reveals that an anxiety reducing molecule may explain why some people handle stress better than others.

This study identified genetic variants that influenced the way the molecule neuropeptide Y (NPY) is expressed. NPY regulates appetite, emotional responses and weight. Genetic variations affect the levels of NPY in the brain and other body tissues.

Subjects with the variant producing the lowest levels of NPY demonstrated less ability to tolerate moderate levels of muscular pain and experienced a stronger emotional response to pain than those with higher NPY levels. Additionally, individuals with the lowest NPY levels had the highest emotional reaction to images of faces with threatening expressions.

Oxytocin, Stress and Genetics

Oxytocin–a hormone that acts as a neurotransmitter–is released in women during labor and childbirth, and while breastfeeding. Both sexes also experience a release of oxytocin during orgasm. Oxytocin is important to social recognition and the bonding that occurs between romantic partners and between mothers and children.

A study published in the Proceedings of the National Academy of Sciences (2009) uncovered a genetic variation in oxytocin’s receptor correlated to empathy and stress levels. Three possible genetic variations of this receptor exist: the AA, AG or GG allele. Because the AA and AG groups were so similar in results, they were combined and compared with the GG subjects.

Results showed that both men and women in the GG group had a lower increase in heart rate during a stressful task than those in the AA/AG group. GG subjects also scored higher on a test of how well they could infer the emotional state of another person. These results indicate that people with the GG allele may be predisposed to cope with stress effectively and be empathetic toward others.

Outsmarting Stress-Related Genes

The genetics of stress isn’t absolute. If you were born with stress-related genes, you aren’t doomed to a life of constant stress and its negative health consequences. A study conducted at Massachusetts General Hospital and the Genomics Center and Beth Israel Deaconess Medical Center (Plos One, 2008) found that the relaxation response alters the expression of stress-related genes in the areas of cell death, inflammation and how the body handles free radicals.

The relaxation response, a term first used by Herbert Benson over 35 years ago, is a state that can be achieved by a techniques such as deep breathing, meditation or prayer.

Resources

Harrison, K. (2010). Oxytocin. Retrieved October 2, 2010, from http://www.3dchem.com/molecules.asp?ID=355

National Institute on Alcohol Abuse and Alcoholism. (2008). Scientists find genetic factor in stress response variability. Retrieved October 2, 2010, from http://www.niaaa.nih.gov/NewsEvents/NewsReleases/geneticfactor.htm

PloS One. (2008). Genomic counter-stress changes induced by the relaxation response. Retrieved October 2, 2010, from http://www.plosone.org/article/info:doi/10.1371/journal.pone.0002576

Proceedings of the National Academy of Sciences. (2009). Oxytocin receptor genetic variation relates to empathy and stress reactivity in humans. Retrieved October 2, 2010, from http://www.pnas.org/content/106/50/21437.abstract?sid=dedc2fe3-12f3-4a3e-8b9a-e06acf9bd8cf

ScienceDaily. (2009). Gene variation linked to individual empathy, stress levels. Retrieved October 2, 2010, from http://www.sciencedaily.com/releases/2009/11/091116163212.htm