A diet rich in fiber-filled foods like healthy cereals and whole grains could lower PTSD risk, study suggests
- Eating two to three fiber sources per day was linked to a lower risk of PTSD in a recent study.
- Fiber could improve communication between the gut and brain, but research is still emerging.
- It's unclear how much diet affects mental health compared to other factors.
A large study has shed light on factors newly linked to post-traumatic stress disorder, finding that, along with poverty and immigration status, diet may be connected to a person's risk of developing PTSD.
Approximately one out of every 20 participants in the study of more than 27,000 people reported experiencing PTSD, and researchers set out to isolate factors that may be tied to their risk.
They found that those who reported eating multiple fiber-rich foods each day had lower odds of developing PTSD. Daily junk food consumption, specifically of pastries or chocolate, was associated with a higher risk of PTSD, according to the study, published in Social Psychiatry and Psychiatric Epidemiology earlier this month.
Researchers aren't sure whether fiber intake has a protective effect on mental health, or if other risk factors for PTSD, like poverty, may affect people's access to nutritious foods. But it's possible that eating fiber-rich foods could improve communication between the gut and the brain, nutritional epidemiologist and study co-author Karen Davison said.
Foods such as whole grains and oats contain soluble fiber, a key nutrient for fueling the good bacteria in your gut. Keeping those bacteria healthy is crucial for not only for the body but also your mind, as recent research has uncovered links between the gut microbiome and mental health.
The gut seems to play a key role in mental health
Dietary fiber could play an important role in the relationship between the gut and the brain, this study suggests. In the process of breaking down fiber, gut bacteria release short chain fatty acids (SCFAs), compounds known to reduce inflammation throughout the body.
Studies have already shown SCFAs improve metabolism and help maintain a healthy immune system, but researchers are just starting to suspect a link to mental health. These compounds could help strengthen your brain and body's communication system, Davison told Insider, although exactly how SCFAs affect the brain has not yet been determined.
Unhealthy foods - like the pastries and chocolates noted in the Canadian study - as well as social factors like economic troubles or divorce can all cause inflammation in the brain and body, and SFCAs may help protect against that damage, Davison said.
However, the complex relationship between mental health, stress, diet, and income makes it difficult to pick out how each of those variables might change someone's gut bacteria, said Valerie Taylor, MD, head of the psychiatry department at the University of Calgary.
We're a long way from using the gut to prevent or treat mental illness
Taylor, who did not work on the PTSD study, has researched whether we may eventually be able to use this kind of information to help people with depression by changing their gut microbiome.
This approach could work for PTSD, too. Just as a depressed person's microbiome has a distinctive combination of bacteria, PTSD is also linked to noticeable bacterial changes. For instance, a person with PTSD may have less of certain species of bacteria than a person without PTSD, even if both people have experienced trauma, research suggests.
The challenge is that we don't know what an optimal microbiome for mental health looks like yet, according to Taylor's research.
There's promising evidence that scientists could one day improve mental health with prebiotics and probiotics - foods and supplements that feed healthy gut bacteria or boost the number of beneficial microbes in the body, respectively.
But until we know more, Taylor said, the best dietary strategy for mental health is to eat whole foods and plenty of fiber, and steer clear of processed foods and added sugar.