COLERAINE, UNITED KINGDOM. Diet plays a significant role in preventing colorectal cancer (cancer of the colon or rectum), which is now the second most common cancer in Australia, Europe, New Zealand and the United States. Colorectal cancer affects about 6% of men and women by the age of 75 years. Several studies have found that an increased intake of vegetables helps protect against the disease. A few years ago it was discovered that members of the Cruciferae and Brassicae families of vegetables, notably broccoli were especially protective. More recently, researchers discovered that sprouted broccoli contains 10-100 times more of the compounds thought to be especially beneficial (sulphoraphanes) than does the whole plant.
Researchers at the University of Ulster now report that a mixture of broccoli, radish, alfalfa and clover sprouts is highly effective in preventing peroxide-induced DNA damage involved in the initiation of cancer. They tested an extract (juice) of the sprouts on the HT29 colon cancer cell line. It was found that cells incubated with the juice were about 50% more resistant to DNA damage caused by exposure to hydrogen peroxide than were non-incubated cells.
The researchers also tested the effect of the sprouts on 10 male and 10 female healthy volunteers. Half the
volunteers were randomized to consume their usual diet as well as 113 grams/day of the sprouts for a 2-
week period. The other half of the group consumed their regular diet. Blood samples were drawn from all
participants at baseline and at the end of the 2-week period. Lymphocytes were isolated from the blood and
checked for DNA damage before and after exposure to hydrogen peroxide. The researchers found that the
DNA in lymphocytes from the sprout-eating group was substantially less likely to be damaged by peroxide at
the end of the 2-week sprout consumption period than was DNA in lymphocytes taken at baseline or from
the control group. They found no difference in antioxidant status (vitamin C, vitamin E, lutein, lycopene, uric
acid) or in the activity of detoxifying enzymes (glutathione peroxidase and superoxide dismutase) between
the groups nor between end of treatment period and baseline. The researchers conclude that young sprouts
may be a potent source of cancer-protecting compounds.