Processing Risk

Processing Risk

Could eating processed foods while pregnant increase the likelihood of childhood autism? Recent findings by UCF researchers suggest yes.

By Nicole Dudenhoefer ’17

Autism diagnoses have risen 15 percent in the past six years, with 1 in 59 U.S. children now being diagnosed with the developmental disorder. As a result, scientists are working diligently to understand the overlapping genetic and environmental factors that cause it. And a group of researchers at UCF may have found a link: processed foods.

Children with autism often experience gastrointestinal issues, which led UCF Professor Saleh Naser to wonder if there’s a link between the gut and brain, and how gut bacteria differ for those who have autism. In a study published in Scientific Reports, Naser and his team, including postdoctoral scholar Latifa Abdelli ’14MS ’15PhD and undergraduate research assistant Aseela Samsam, discovered that a food preservative known as propionic acid (PPA) can alter how a fetus’s brain develops during pregnancy, leading to autism.

“It’s my hope that our study will motivate other scientists to look into the role of PPA in the development of autism with the goal of eliminating the condition as we know it,” says Naser, who has 25 years of experience studying gastroenterology.

Here’s how it happens:

PPA is a naturally occurring acid released in our digestive tract as food ferments. It’s also produced chemically as a food preservative for bread and to flavor products such as processed cheese.


If a pregnant woman consumes a significant amount of processed foods, PPA levels can spike.


In excess, PPA impacts a fetus’ brain by reducing the development of neurons — cells that tell other body cells how to function. This can also damage neurons’ communication pathways throughout the body.


High amounts of PPA also cause an overproduction of glial cells. These cells protect neuron function, but too many cells disrupt the connection between neurons and causes inflammation in the brain and the rest of the body.


Typically there is a one-to-one ratio of neurons to glial cells, but in Naser’s study high levels of PPA threw off this balance with a one-to-four ratio. This smaller number of neurons also exhibited abnormal qualities in the study. Together, these issues result in behaviors associated with autism, such as difficulty communicating in social settings and repetitive behaviors such as rocking.

What is Autism?
Autism is a disorder covering a wide range of conditions that include challenges with social skills, repetitive behaviors, and speech and nonverbal communication. Other sensory sensitivities and medical issues, such as seizures and gastrointestinal disorders, often accompany the condition. Since autism affects people differently, some people diagnosed with it live independently while others may need varying levels of daily support.

Which Foods Contain PPA?
Store-bought breads, baked goods, processed cheese, dried fruits and juices often contain some form of PPA as a preservative.

Check labels for these ingredients:

  • Sodium propionate/propanoate
  • Calcium propionate/propanoate
  • Methyl propionate/propanoate