Transcript: Second Strategy to Cooking Broccoli
When I used to teach medical students at Tufts, I gave a lecture about this amazing new therapeutic called iloccorB. I’d talk about all the new science, all the things it could do, excellent safety profile and just as they were all scrambling to buy stock in the company and prescribe it to all their patients I did the big reveal, apologizing for my dyslexia, I had got it backwards. All this time I had been talking about broccoli.
Sulforaphane, is thought to be the main active ingredient in broccoli, which may protect our brain, protect our eyesight, protect against free radicals, induce our detoxification enzymes, help prevent cancer, as well as help treat it. For example I’ve talked about sulforaphane targeting breast cancer stem cells.
But then I talked about how the formation of this compound is like a chemical flare reaction, requiring the mixing of a precursor compound with an enzyme in broccoli, which is destroyed by cooking. This may explain why we get dramatic suppression of cancer cell growth from raw broccoli, cauliflower, Brussels sprouts, but hardly anything boiled microwaved or steamed, except for microwaved broccoli —that actually retained some cancer fighting abilities. But who wants to eat raw Brussels sprouts?
I shared a strategy, though, for to how to get the benefits of raw in cooked form. In raw broccoli, when the sulforaphane precursor, called glucoraphanin, mixes with the enzyme, called myrosinase, because you chewed or chopped it, given enough time—sitting in your upper stomach for example, waiting to get digested, sulforaphane is born. Now the precursor is resistant to heat, and so is the final product, but the enzyme is destroyed. And with no enzyme, there’s no sulforaphane production.
That’s why I described the hack and hold technique. If you chop the broccoli, Brussels sprouts, kale, collards, or cauliflower first, and then wait 40 minutes, then you can cook them all you want. The sulforaphane is already made, the enzyme is already done doing its job, so you don’t need it anymore.
When most people make broccoli soup, for example. they’re doing it wrong. Most people cook the broccoli first, then blend it, but now we know it should be done the exact opposite way. Blend it first, wait, and then cook it. What if we’re using frozen broccoli, though? Here’s the amount of sulphorane in someone’s body after they eat broccoli soup made from fresh broccoli. Hits their bloodstream within 15 minutes. Here’s after frozen.
Commercially produced frozen broccoli lacks the ability to form sulforaphane because vegetables are blanched, flash-cooked, before they’re frozen for the very purpose of deactivating enzymes. This prolongs shelf life in the frozen foods section, but the enzyme is dead by the time you take it out of your freezer, so it doesn’t matter how much you chop it, or how long you wait, no sulforaphane is going to be made. This may be why fresh kale suppresses cancer cell growth up to 10 times more than frozen.
The frozen is still packed with the precursor—remember that’s heat resistant, and they could make lots of sulforaphane out of the frozen broccoli by adding some exogenous enzyme. Where do you get myrosinase enzyme from? They bought theirs from a chemical company, but we can just walk into any grocery store.
This is another cruciferous vegetable, mustard greens. All cruciferous vegetables have this enzyme. Mustard greens, grow out of little mustard seeds, which you can buy ground up in the spice aisle as mustard powder. So if you sprinkled some mustard powder on your cooked frozen broccoli, would it start churning out sulforaphane? We didn’t know, until now.
Boiling broccoli prevents the formation of any significant levels of sulforaphane due to inactivation of the enzyme. However, addition of powdered mustard seeds to the heat processed broccoli significantly increased the formation of sulforaphane. Here’s the amount of sulforaphane in boiled broccoli; this is how much you get if you add a teaspoon of mustard powder. That’s a lot though. How about a just a half teaspoon? About the same amount, suggesting you could use even use less. Domestic cooking leads to enzyme inactivation of myrosinase and hence stops sulforaphane formation, but addition of powdered mustard seeds to cooked cabbage-family vegetables provides a natural source of the enzyme and then it’s like you’re practically just eating it raw. So, if you forget to chop your greens in the morning for the day, or are using frozen, just sprinkle some mustard powder on top at the dinner table and you’re all set. Or some daikon radish, or horseradish, or wasabi—all cruciferous vegetables packed with the enzyme. Here they used just like a quarter teaspoon for seven cups of broccoli, so just a tiny pinch can do it. Or you can add a small amount of fresh greens to your cooked greens. Right—because the fresh greens have that enzyme that can go to work on the precursor in the cooked greens.
One of the first things I used to do in the morning is chop my greens for the day and so when lunch and supper rolls around they’re good to go, as per the hack and hold strategy, but now with the mustard powder plan I don’t have to prechop.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Katie Schloer.
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