Green tea is known to be a powerful antioxidant, and its health benefits have been glorified by many. However, the latest experiments in lab rats suffering from IBD reveal that when green tea is consumed in combination with dietary iron, it may actually lessen its benefits.

"If you drink green tea after an iron-rich meal, the main compound in the tea will bind to the iron," said Matam Vijay-Kumar, assistant professor of nutritional sciences at Penn State University.

"When that occurs, the green tea loses its potential as an antioxidant. In order to get the benefits of green tea, it may be best to not consume it with iron-rich foods," said Vijay-Kumar, who added that these results are also applicable to iron supplements. Iron-rich foods include kale, spinach red meat and other green leafy vegetables.

According to Vijay-Kumar and his team of researchers, EGCG - the main compound in green tea - impedes a pro-inflammatory enzyme, myeloperoxidase, which is released by white blood cells when it experiences inflammation. While EGCG in itself may be beneficial in controlling the inflammatory bowel disease, when consumed with iron, the same compound loses its power to control myeloperoxidase. The findings of the study were published in American Journal of Pathology.

IBD is a stomach disorder associated with inflamed digestive tract that leads to pain, fatigue, weight loss, diarrhea and other symptoms including anemia or iron deficiency. People suffering from IBD are often recommended to take iron supplements. In this case, taking green tea along with iron supplements or iron-rich foods will be less effective than helpful as both the nutrients are counterproductive to one another.

"It is important that IBD patients who take both iron supplements and green tea know how one nutrient affects the other," Vijay-Kumar said. "The information from the study could be helpful for both people who enjoy green tea and drink it for its general benefits, as well as people who use it specifically to treat illnesses and conditions."

"The benefit of green tea depends on the bioavailability of its active components," said Beng San Yeoh, graduate student in immunology and infectious diseases and first author of the study. "It is not only a matter of what we eat, but also when we eat and what else we eat with it."

The study was funded by the National Institutes of Health.