Cruciferous vegetables are known to have possible anti-cancer effects, and a new study published last week in PLOS ONE adds to the growing evidence. In broccoli, researchers at the Baylor College of Medicine in Texas found a concentrated form of a compound called sulforaphane, shown to reduce the number of acute lymphoblastic leukaemia cells in the lab.
"Acute lymphoblastic leukaemia is a type of cancer of the white blood cells common in children," says Dr Daniel Lacorazza, assistant professor of pathology and immunology. "There is about an 80 per cent cure rate, but some children don't respond to treatment. For those cases, we are in need of alternative treatments."
Sulforaphane is also found naturally in other members of the cruciferous, or cabbage, family of vegetables. It's believed to have both preventive and therapeutic properties in solid tumours. Studies have shown that people who eat a diet rich in cruciferous vegetables have a lower risk of some cancers.
However, there have not been definitive studies showing how this compound interacts with blood cancers, says Lacorazza. So researchers, led by Dr Koramit Suppipat, who performed the work while a clinical fellow in the Texas Children's Cancer and Haematology Centres, incubated human-derived leukaemic cell lines and primary lymphoblasts from paediatric patients with the compound.
The cancer cells died while the healthy cells from healthy donors were unaffected. Studies tested in pre-clinical mouse models showed similar results. Lacorazza says the compound works by entering the cells and reacting with certain proteins - but further research will determine which proteins and how.
But lots of broccoli would be needed, as concentrated, purified sulforaphane was used in the study. "So while eating cruciferous vegetables is good for you," says Lacorazza, "it will not have the same effect as what we saw in the lab."
Test your knowledge of cruciferous vegetables below.
1. Which of the following is not a cruciferous vegetable?
b. Bak choy
2. Sulphur-containing chemicals in cruciferous vegetables are responsible for their pungent aroma and bitter flavour. What are these chemicals called?
3. Cruciferous vegetables are rich in other nutrients, including
b. Vitamins C, E and K
4. Which cruciferous vegetable has the most plant omega-3s (which are believed to protect against cardiovascular disease)?
b. Brussels sprouts
Answers: 1. c; 2. a; 3. all are correct; 4. b