Instant noodles have long been a popular meal option, loved for their convenience and low cost. But a new study suggests they may increase the risk for heart disease and stroke. And the study has sparked renewed interest in an eye-opening video that shows how our stomachs handle processed foods.

The study, published last week in The Journal of Nutrition, was based off of data from the Korean National Health and Nutrition Examination Survey from 2007-2009.

Using the survey data, researchers examined the diets of a total of 10,711 adults between the ages of 19-64.

They found that consumption of instant noodles two or more times a week was associated with a higher prevalence of metabolic syndrome in women but not in men. Metabolic syndrome is set of conditions – including high blood pressure, high blood sugar, excess abdominal fat and abnormal cholesterol -- which combined increase the risk for heart disease, stroke and diabetes.

The study's lead investigator, Dr. Hyun Joon Shin, said the observed differences between the women and men in the study are likely attributable to biological differences between the sexes, including sex hormones and metabolism.

Shin also said that a chemical found in the instant noodle packaging may be another factor affecting the gender difference.

The study says a chemical called bisphenol A (BPA) is commonly found in styrofoam containers used to hold some brands of instant noodles. Studies have shown that BPA can interfere with the body's hormones, particularly the female sex hormone estrogen, Shin said in a statement.

Shin, who is a clinical cardiology fellow at Texas' Baylor University Medical Center, said the results of the study highlight the importance of understanding the impact of what types of foods and substances we put into our bodies.

"This research is significant since many people are consuming instant noodles without knowing possible health risks," he said in the statement. "My hope is that this study can lay a foundation for future research about the health effects of instant noodle consumption."

This isn't the first time the ingredients found in instant noodles have come under scrutiny.

A stomach-churning 2011 video showed for the first time how our bodies differently digest instant noodles compared to homemade noodles. 

Using tiny cameras that can be ingested, participants in a small trial ate processed instant noodles and homemade noodles. They then swallowed the camera, which transmitted video footage from inside their gastrointestinal tract.

Video footage from inside the digestive tract showed stark differences.

The digestive tracts are seen contracting and convulsing to break down the noodles. More than two hours after consumption, the instant noodles aren’t broken down, and their shape and colour are still largely recognizable. By comparison, the homemade noodles are nearly completely broken down.

In the video, which was featured by TEDxManhattan, the ingredient tertiary-Butylhydroquinone (TBHQ) is named as a possible culprit. TBHQ is an anti-oxidant derived from petroleum that is commonly used as a preservative.