Possible Links with Childhood Stress and Diet
(COLUMBIA, Tenn. – Jan. 3, 2012) - - - A recent study published in the Journal of Behavioral Optometry points to a significant link between childhood stress, childhood diet and the development of myopia (nearsightedness).
Louise Katz, Ph.D., a professor of psychology at Columbia State Community College, read that as many 60 percent of young adults in the United States have been estimated to be nearsighted, and in some countries the numbers are as high as 80 percent. The rapid increase led Katz to believe that genetics was not the only factor at play. In a study conducted by Katz and co-author Warren Lambert, Ph.D., a senior research associate at Vanderbilt University, a strong correlation has been identified between myopia development and childhood diet and stress.
“The number of people who are nearsighted has increased so dramatically,” Professor Katz said. “Even as recently as 50 years ago it wasn’t the percentage it is now. It’s just too big of an increase, which means that there has to be something going on in the environment.”
According to Katz, basic research on psychological factors related to myopia development had not been done. Although it has been reported that diet may be associated with vision problems such as night blindness, cataracts and macular degeneration, its potential link to myopia development in children had not been explored.
The goal of the study was to find preliminary evidence of behavioral and environmental factors that people can control in regards to the development of myopia. Katz based her findings on biological, psychological and social factors such as psychological stress, diet, near work and time spent outdoors. To examine the possible link to myopia Katz surveyed 417 of her undergraduate students using a questionnaire of more than 100 questions that pertained to their childhood.
The results of the study indicated that participants with myopia reported significantly less fresh fruits and vegetables and whole grains in their childhood diet. Myopic participants also reported less often playing outdoors; less light while reading; more time spent watching television; and more of a family history of myopia.
“Consumption of fresh fruits and vegetables and whole grains came out extremely significant, but this doesn’t mean it’s the only factor,” Katz said. “Some people had lots of fresh fruits and vegetables and whole grains and still became nearsighted. Research results indicate that not one factor accounts for the myopia and maybe that is why it has eluded understanding for so long.”
Also indicated in the study was that people who are nearsighted tend to have one or more parents who were also nearsighted, as well as other nearsighted relatives. Katz explained that research has found that there is a stronger correlation between siblings than between children and parents.
“This does not prove a genetic factor,” Katz said. “There is likely genetic predisposition, but people in the same family tend to eat the same foods, tend to have the same habits and share many environmental things in common, other than genetics. Overall, environmental factors have more weight than the genetic factor.”
Study results also indicate that time spent in childhood using a computer and reading did not show a relationship to nearsightedness, but less light while reading showed a strong relationship to nearsightedness.
The study also reported that participants who were nearsighted reported less childhood stress than the students who had normal vision. Typically, stress causes physical problems in people, not the opposite. Katz said that these results, which were extremely strong statistically, raise the possibility that myopia may have an impact on the way people perceive stress.
Katz plans to do a follow-up study on the stress factors in order to explore the meaning of her findings, but she suggests in the short-run that parents make simple dietary changes, encourage outdoor play and increase desk lighting, all of which could help prevent nearsightedness in their children.
Katz has been a Columbia State faculty member since 1992, and she resides in Williamson County. She teaches classes in developmental psychology, introductory psychology, social psychology and psychology of adjustment, and she is a licensed psychologist in Tennessee. For details on her study, visit http://www.columbiastate.edu/lkatz/faculty/Research-on-Development-of-Myopia-in-Children.
Columbia State is a two-year college, serving a nine-county area in southern Middle Tennessee with locations in Columbia, Franklin, Lawrenceburg, Lewisburg and Clifton. As Tennessee’s first community college, Columbia State is committed to increasing access and enhancing diversity at all five campuses. Columbia State is a member of the Tennessee Board of Regents, the sixth largest higher education system in the nation. For more information, please visit www.columbiastate.edu.
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