Another 25 infected people consumed an equivalent amount of alfalfa sprouts which, although rich in phytochemicals, don't contain sulforaphane.
The researchers assessed the severity of Helicobacter infection at the start of the study, after four and eight weeks of treatment, and again eight weeks after intervention was stopped.
They found that eating a daily dose of broccoli sprouts reduced by more than 40 percent the level of HpSA, a highly specific measure of the presence of components of H. pylori shed into the stool of infected people.
There was no HpSA level change in control subjects who ate alfalfa sprouts. The HpSA levels returned to pretreatment levels eight weeks after people stopped eating the broccoli sprouts, suggesting that although they reduce H. pylori colonization, they do not eradicate it.
"We know that a dose of a couple ounces a day of broccoli sprouts is enough to elevate the body's protective enzymes," says Jed W. Fahey, an author of the paper who is a nutritional biochemist in the Johns Hopkins University School of Medicine.
"That is the mechanism by which we think a lot of the chemo protective effects are occurring. What we don't know is whether it's going to prevent people from getting stomach cancer. But the fact that the levels of infection and inflammation were reduced suggests the likelihood of getting gastritis and ulcers and cancer is probably reduced," he said.
Citing their new "demonstration of principle" study, the international team of scientists caution that eating sprouts containing sulforaphane did not cure infection by H. pylori. They do not suggest that eating this or any amount of broccoli sprouts will protect anyone from stomach cancer or cure GI diseases.
