15th March, 2012
Laboratory and clinical studies have shown that eating cruciferous vegetables (which includes cabbage, broccoli, and cauliflower) can aid in cancer prevention. Sulforaphane appears to be the key compound in these vegetables which gives them anti-cancer activity, and it is particularly abundant in broccoli. Recent research suggests that sulforaphane acts to prevent cancer by influencing at least two epigenetic mechanisms.
Epigenetics describes processes which act to alter the way our genes are ‘expressed’; in short, they enable us to respond to our environment by switching genes on or off. This is important in normal development, and for the maintenance of health, but if for any reason the system gets out of control, it can contribute to diseases such as cancer and heart disease. This is where compounds such as sulforaphane can be important, correcting the out-of-control mechanisms to ensure the right genes are switched on.
Sulforaphane’s ability to influence histone deacetylases or HDACs, one of the key epigenetic mechanisms, is well known. What is new is its ability to influence DNA methylation, a second epigenetic mechanism. According to associate professor Emily Ho, one of the key researchers in this study (Hsu et al., 2011), "it appears that DNA methylation and HDAC inhibition, both of which can be influenced by sulforaphane, work in concert with each other to maintain proper cell function," thus delivering the one-two punch that’s a potential knockout for cancer.
This research is consistent with preliminary conclusions drawn by NuNZ’s programme leader, Lynnette Ferguson, along with Ralf Schlothauer from Comvita New Zealand. A paper written by Lynn and Ralf and published this year (Ferguson & Schlothauer, 2012) stressed the potential importance of epigenetic mechanisms in the cancer-reducing properties of broccoli.
The same processes disrupted in cancer which sulforaphane may act on also appear to play a role in other neurodegenerative diseases, including cardiovascular disease, immune function, neurodegenerative disease and even aging. So we should keep eating those greens – they might be more beneficial for our health than we ever thought possible!
- Ferguson LR & Schlothauer RC (2012) The potential role of nutritional genomics tools in validating high health foods for cancer control: broccoli as example. Mol Nutr Food Res 56, 126-146.
- Hsu A, Wong CP, Yu Z, Williams DE, Dashwood RH & Ho E (2011) Promoter de-methylation of cyclin D2 by sulforaphane in prostate cancer cells. Clin Epigenetics 3, 3.