Ian Rowland, professor of human nutrition at the University of Ulster's School of Biomedical Sciences, said that his team saw clear protective effects against DNA damage in blood cells from healthy adults who had eaten just over 100 grams of sprouted vegetables every day for a fortnight.
The researchers previously tested a mixture of three-day old seedlings from vegetables including broccoli, radish, alfalfa and clover sprouts on human cells in vitro and found significant results.
The human trial, to be published this summer in Cancer, Epidemiology, Biomarkers and Prevention, involved 10 healthy participants and 10 control subjects.
"There was no difference when we measured the background level of damage in blood cells but when we treated the cells with hydrogen peroxide to induce DNA damage, we found the cells from the sprout group were protected against damage compared to the controls," Professor Rowland told NutraIngredients.com.
DNA damage is commonly used as a biomarker for cancer as it has been found to play an important role in disease progression, he added. Sources of DNA damage include diet-related carcinogens, and bodily processes like oxidative stress.
The researcher noted that it is difficult to identify the compounds in the vegetables responsible for the protective effect, however broccoli and sprouts are known to contain glucosinolates, previously demonstrated to have an anti-cancer action.
Alfalfa and clover contain isoflavones, also linked to cancer prevention.
"We wanted to use seedlings because they are thought to have higher levels of these compounds than the mature plants - they are at a more sensitive stage and therefore producing more of these protective chemicals," said Professor Rowland.
While the research does not yet confirm this, he added that the Ulster team is keen to follow up the study with further investigation into the chemicals involved.
Future findings could be important in the face of increasing government promotion of the benefits of eating enough fruit and vegetables.
The findings were presented at BioIreland 2004 - Stepping Stones To Success, a biotechnology conference being held at the University's of Ulster's Coleraine campus from 20-22 June.