When working with lab mice, the team discovered that their mice could better tolerate digestive issues after eating broccoli than mice who weren't fed any veg. According to Gary Perdew, professor of agricultural sciences at Penn State, "there are a lot of reasons we want to explore helping with gastrointestinal health and one reason is if you have problems, like a leaky gut, and start to suffer inflammation, that may then lead to other conditions, like arthritis and heart disease."
The researchers believe that broccoli was effective thanks to the way certain compounds it contains bind to stomach receptors called Aryl hydrocarbon receptors, or AHRs. When cruciferous vegetables such as broccoli are broken down in the stomach, one of the resulting compounds is called indolocarbazole, or ICZ, which in turn has been found to bind to AHR.
"When ICZ binds to and activates the Aryl hydrocarbon receptor (AHR) in the intestinal lining, it aids in maintaining a healthy balance in the gut flora and immune surveillance, and enhances host barrier function," according to the research team. "This may help prevent diseases, such as various cancers and Crohn's Disease, caused by inflammation in the lining of the gut."
In their study, the researchers worked with two types of mice which were genetically different. One type had an enhanced ability to bind ICZ to AHR, while the other type had a reduced ability to do so. All mice were placed on a diet which contained either 15% broccoli or which contained no broccoli at all. The results showed that after being given substances to cause digestive issues, only those mice that had consumed broccoli managed to escape the uncomfortable symptoms.
To consume an equivalent amount of broccoli, humans would need to eat 3 and a half cups each day, which may definitely be quite a lot for some people. However, Perdew claims that there may be alternative ways of getting the ICZ-to-AHR binding benefits.
"Now, three and a half cups is a lot, but it's not a huge amount, really," he claims. "We used a cultivar — or variety — with about half the amount of this chemical in it, and there are cultivars with twice as much. Also, brussels sprouts have three times as much, which would mean a cup of brussels sprouts could get us to the same level."