Broccoli & Mustard, a love story
Everyone knows Broccoli is good for you. But do you really know why? And do you know how to maximise it’s benefits in the kitchen?
Well firstly, I want to introduce you to an important phytochemical called sulforaphane, one of the most powerful anticarcinogens found in food. Broccoli and other cruciferous vegetables are a top source of sulforaphane. In fact the best source of sulforaphane is broccoli sprouts.
Compared to mature broccoli, broccoli sprouts can contain up to x100 more of the sulforaphane precursor glucoraphanin.
Why is sulforaphane so important? Sulforophane lowers DNA damage by reducing oxidative stress and inflammation. These processes are central to cancer, ageing, heart disease and neurodegenerative diseases. Notably, sulforaphane is the most potent naturally occurring dietary activator of a biological pathway in the body called NRF2. NRF2 is an important pathway that controls over 200 genes in the body, many of which are involved in processes that slow cellular ageing, excrete carcinogens and mitigate inflammation.
The enzyme myrosinase in broccoli and other crucifers is needed for sufulforaphane to form from its precurser glucoraphanin. Boiling broccoli for example leads to myrosinase inactivation and prevents sulforaphane formation. However, research now shows how to maximize the cancer-fighting power of broccoli.
Research led by the University of Illinois, compared boiling, microwaving, and steaming and found steaming broccoli for up to five minutes was the best way to retain its myrosinase. Boiling and microwaving broccoli for one minute or less destroyed the majority of the enzyme. A study further showed that steaming broccoli for three to four minutes will optimize the sulforaphane content by eliminating epithiospecifier protein (which inactivates sulforaphane) while still retaining the enzyme myrosinase. A similar effect can be achieved by heating broccoli to 60℃ for 10 minutes or broccoli sprouts to around 70℃ for 10 minutes (see study). But if you still prefer to boil or buy frozen broccoli don't despair, there is a remedy to salvage the myrosinase. Studies have now shown that the addition of powdered mustard seeds to the heat processed broccoli significantly increased the formation of sulforaphane. It turns out the mustard seed contains a particularly resilient form of myrosinase. Such that mustard seeds can boost sulforaphane formation even in boiled broccoli (see study).
So if you're using frozen or boiled brocolli, be sure to add a myrosinase-containing food such as mustard seed, daikon radish, horseradish or arugula (rocket) to fully optimise your sulforaphane hit. I highly recommend growing your own broccoli sprouts to really nail your sulforaphane intake. It’s so easy, all you need is some broccoli seeds and a sprouter which can be found at any health food shop these days. I also use this organic mustard seed powder to sprinkle on my cooked crucifers.
And if cruciferous vegetables give you gas, try pureeing them or at least chewing them very well. You could also experiment with probiotics.
Other notable studies on preparation techniques that maximize plant foods’ nutrition and cancer protective compounds:
- Crushing garlic then waiting 10 minutes before cooking allows its inactive compounds to convert into the beneficial phytochemical allicin.
- Cooking tomatoes allows our body to more easily absorb the phytochemical lycopene.
- Eating black pepper together with turmeric increases the bioavailability of turmeric.
Hope this post has convinced you to eat more crucifers (with mustard!), grow some broccoli sprouts and think more about the way we process our food in the kitchen. In case you want to read on about broccoli’s anti-cancer activity, here you go: