Don’t boil the broccoli

Remember the floppy cabbage and squishy sprouts Granny used to make? New research published in the British Journal of Nutrition reveals how boiling the life out of your veg destroys its valuable anti-cancer properties. In autumn 2005, we revealed how compounds found in cruciferous vegetables such as broccoli, Brussel sprouts, cauliflower and kale help protect against cancer (Veggiehealth issue 9). In this new study, lead researcher Vanessa Rungapamestry invited volunteers to come for a free lunch – but they had to eat their greens! Rungapamestry found that the longer the veg was boiled for, the higher the losses of important anti-cancer compounds. This research is supported by earlier work that showed how boiling vegetables for 30 minutes caused losses of 58-77 per cent of protective compounds while boiling for just five minutes caused losses of 20-30 per cent. Steaming for 0-20 minutes and stir-frying for 0-5 minutes caused no significant loss. So if you want to get the maximum benefit from your five-a-day… boiling is out!

_{Song, L. and Thornalley, P.J. 2007. Effect of storage, processing and cooking on glucosinolate content of Brassica vegetables. Food and Chemical Toxicology. 45 (2) 216-224.}

_{Rungapamestry, V., Duncan, A.J., Fuller, Z. and Ratcliffe, B. 2007. Effect of meal composition and cooking duration on the fate of sulforaphane following consumption of broccoli by healthy human subjects. British Journal of Nutrition. 97 (4) 644-652.}