- People who eat two or more sources of fiber daily are less likely to have post-traumatic stress disorder (PTSD) than those who eat less fiber.
- There is a correlation between eating chocolate and a higher incidence of PTSD.
- PTSD is more common among people living in poverty and among women.
- People who are migrants and not white are 50% more likely to have PTSD than white Canadians.
A new analysis of data from the Canadian Longitudinal Study on Aging (CLSA) finds statistical associations between various health factors and PTSD.
According to the authors of the new study, which appears in Social Psychiatry and Psychiatric Epidemiology, the research does not establish that these factors actually cause PTSD, and the reverse may be true. However, their identification may nonetheless inform further research.
In some cases, the authors posit that underlying physiological mechanisms may be at play.
The CLSA is a large, long-term study of the Canadian population that has been ongoing for more than 20 years. The researchers behind the new study examined the data for 27,211 individuals aged 45–85 years. Of these people, 1,323 had PTSD.
The study found that people who eat two or three sources of fiber per day are less likely to experience episodes of PTSD than those eating less fiber.
Lead author Karen Davison, director of the Nutrition Informatics Research Group and health science program faculty member at Kwantlen Polytechnic University in Surrey, British Columbia, suggests a reason for this finding: “It is possible that optimal levels of dietary fiber have some type of mental health-related protective effect.”
Davison says that this may have to do with short chain fatty acids (SCFAs), which originate in the gut. “SCFA molecules can communicate with cells and may affect brain function,” she explains.
The researchers also linked the consumption of other foods to a higher incidence of PTSD. These foods included chocolate, pastries, nuts, and pulses.
Co-author Christina Hyland, a doctoral student at the University of Toronto (U of T), calls the finding unexpected.
She cautions, however, that the inclusion of nuts on the list may reflect the inclusion of peanut butter, but not more healthful nut options, among the food choices in the CLSA.
When they looked at nondietary factors, the researchers found a strong association between poverty and PTSD. Of the individuals with an annual household income below $20,000 Canadian, 1 in 7 experienced the disorder.
Senior author Prof. Esme Fuller-Thomson, director of the Institute for Life Course & Aging and professor at the U of T, says that this is one of those links in which the cause and effect are unclear.
“Unfortunately, we do not know whether PTSD symptoms undermined an individual’s ability to work, which resulted in poverty, or whether the stress associated with poverty exacerbated PTSD symptoms in respondents,” Prof. Fuller-Thomson notes.
The results showed that 6.9% of women and 3.9% of men had PTSD, meaning that it affected women nearly twice as often as men.
Among the women, 8.8% of those who were divorced or widowed had PTSD compared with 4.4% of currently married women or women with a common-law partner.
The study’s analysis supports
Men are most likely to have PTSD in their early 40s, while women most often experience it in their early 50s.
The analysis revealed links between PTSD and both chronic pain and smoking. Meghan West, a master of social work student at the U of T, notes, “This is consistent with results from other studies, which found increased risks of cardiovascular, metabolic, and musculoskeletal conditions among individuals with PTSD.”
“These links may be due to alterations in the hypothalamic-pituitary-adrenal axis (HPA axis), sympathetic nervous system inflammation, or health behaviors that increase the risk of poor physical health,” she adds.
The study also found that migrants who were not white were twice as likely to experience PTSD as white migrants (7.5% compared with 3.6%). They were also 50% more likely than Canadian-born white individuals (5.6%) to have PTSD.
Co-author Dr. Hongmei Tong, assistant professor of social work at MacEwan University in Edmonton, Ontario, suggests that the cause may be the challenges that migrants face before arriving in their adopted country, especially when they are coming from nations in which armed conflict is common.
“Immigrants from these regions are also more likely to have experienced traumatic incidents, such as natural disasters and armed conflict, and could be at greater risk of PTSD as a result. As such, there may be a greater need for mental health resources for visible minority immigrants,” she says.
The many associations that the study revealed between PTSD and various factors suggest that anyone hoping to provide support for people who experience the disorder should consider the wide range of possible factors contributing to its occurrence.
The authors conclude:
“Interventions aimed at managing PTSD in mid-age and older adults should consider ethnicity, immigrant status, as well as socioeconomic, health, and nutrition status.”