“The good news from the study is that it appears that when PTSD symptoms abate, risk of becoming overweight or obese is also significantly reduced,” Laura D. Kubzansky, Ph.D, at Harvard School of Public Health and lead author of the study, stated in a press release. The researchers, a team assembled from Columbia University’s Mailman School of Public Health and Harvard, published their work in JAMA Psychiatry.
How Many Suffer PTSD?
PTSD can develop after a terrifying ordeal, usually one that involved the threat or act of physical harm. Many people assume PTSD is only associated with war, but all manner of traumatic incidents, including mugging, rape, torture, being kidnapped or held captive, child abuse, car accidents, train wrecks, plane crashes, bombings, or natural disasters such as floods or earthquakes, can trigger the disorder. Although experiencing a trauma is common — nearly 60 percent of men and half of all women experience at least one trauma in their lives — this does not mean a person will develop PTSD. In fact, only a small portion of people develop PTSD during their lifetime: about 10 percent of women and half as many men, which amounts to nearly 5.2 million adults during any given year.
For some time it has been clear that women with PTSD generally have higher rates of obesity, but how these two factors relate has never been clear. To explore whether PTSD drives weight gain, the researchers analyzed data collected from 50,504 women, ages 22 and 44, who participated in the Nurses’ Health Study II during a 20 year period beginning in1989. They asked participants about any symptoms they may have experienced as a result of trauma. Common symptoms include re-experiencing the traumatic event, feeling under threat, social avoidance, and numbness.
The researchers discovered that normal-weight women who developed PTSD — in this case, the disorder was defined as persistence of four or more symptoms for a month or longer — had a 36 percent increased risk of becoming overweight or obese, compared to women who experienced trauma but had no symptoms of PTSD. For those women whose PTSD symptoms appeared prior to the study, body mass index increased at a more rapid pace than women without PTSD.
Reasons Behind the Weight
The researchers believe the effect of PTSD on obesity may be stronger in the general population. “Nurses are great for studies because they report health measures like BMI with a high degree of accuracy,” Karestan Koenen, Ph.D, associate professor at Mailman School and senior author, explained in a press release. “But they are also more health conscious and probably less likely to become obese than most of us, which makes these results more conservative than they would otherwise be.”
How can PTSD lead to weight gain? The researchers have a number of theories, including one based on the possibility of over-active stress hormones. In such a case, PTSD would be found to disturb the function of the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system, each of which are involved in regulating metabolism as well as other bodily processes. Another theory is women with PTSD simply eat more and develop other unhealthy behavior patterns as an ineffective way to cope. Ongoing research is examining whether PTSD might increase the preference for processed foods and decrease the likelihood of exercising.
“PTSD is not just a mental health issue,” Koenen told the press. Unfortunately, researchers estimate that only half of American women with the disorder are ever treated, despite increasing evidence of far-reaching problems associated with it.
Source: Koenen K, Kubzansky LD, Bordelois P, et al. JAMA Psychiatry. 2013.
(image: shutterstock)