Sulforaphane, glucoraphanin, and myrosinase: Broccoli's health benefits explained

Maybe you’ve been considering growing broccoli in your garden. Maybe you’re considering making the switch to microgreens for more flavorful meals. Or maybe you just heard Dr. Rhonda Patrick and Joe Rogan talking about broccoli sprouts. 

Whatever the reason, you’ve made the decision that you want more broccoli in your life. But you’re still wondering...why is broccoli so great for health? What are the bioactive compounds glucoraphanin and myrosinase? And how do they relate to sulforaphane (pronounced ‘sull-fore-uh-fane’), the superfood molecule that everyone is talking about?

RELATED: 15 Science-Based Benefits of Sulforaphane

What is Glucoraphanin?

Glucoraphanin (pronounced ‘gloo-koh-raff-uh-nin’) is an important natural chemical that belongs to a group of powerful plant compounds called glucosinolates (pronounced ‘gloo-koh-sin-oh-lates’). Glucosinolates are compounds that contain a sulfur group and are typically described as pungent; they have strong flavors and smells.

The most important chemical aspect of glucosinolates is the fact that they convert into isothiocyanates (pronounced ‘ iso-thyo-siyah-nates’). This is a group of important chemicals commonly called “mustard oils.” 

While most glucosinolates like glucoraphanin are produced in the mustard family (Brassicaceae for all you botany lovers!), you can find glucosinolates in a few other plants as well. The plant genera Drypetes and Putranjiva also make mustard oils. Plants that contain mustard oils make these powerful oils for protection against insects–bugs don't like that pungent flavor as much as humans do!

There are cultivars of glucoraphanin-rich foods, such as broccoli, that have been bred to increase the levels of glucoraphanin. For instance, romanesco broccoli and “super broccoli” contain many times more glucoraphanin than the typical broccoli you find in the grocery store, and red cabbage can have higher levels of glucoraphanin than adult broccoli.

More glucoraphanin usually means more sulforaphane if processed correctly, so remember to eat your brassicas (cruciferous veggies) raw or just gently cooked, and to chew thoroughly for the best health benefits.

What is myrosinase?

Like we mentioned above, bugs don’t like mustards very much because of their pungent flavor. Myrosinase (pronounced ‘my-roh-sin-ayze’) is another one of the things that helps deter bugs from eating plants in this group.

Myrosinase is an enzyme–that means it’s a chemical that helps make a specific chemical reaction happen. Myrosinase is the key to unlocking the health benefits of cruciferous veggies like broccoli, because it converts glucosinolates (like glucoraphanin) into sulforaphane.

Remember when we said cook your broccoli gently? The reason this is important is because heat deactivates enzymes. If we deactivate myrosinase, the glucoraphanin stays glucoraphanin.

Without myrosinase, it doesn’t matter how much glucoraphanin is in your food because it won’t be converted into health-boosting sulforaphane. Be cautious when buying sulforaphane supplements – if they don’t contain myrosinase too, they won’t have much of an effect. 

Myrosinase foods

Because glucoraphanin and myrosinase tend to occur together in the same biochemical gene pathways, foods with lots of glucoraphanin are also foods with myrosinase–cruciferous veggies. 

However, some foods have exceptionally high myrosinase, and these are mustard seeds and greens, radish, watercress, wasabi, daikon and broccoli. Try mixing several cruciferous veggies into your next meal to increase the amount of myrosinase and glucoraphanin in your dish.

Glucoraphanin and myrosinase

So we know that cruciferous veggies have glucoraphanin and that myrosinase enzyme turns glucoraphanin into sulforaphane. But how does this actually happen?

Glucoraphanin and myrosinase are like housemates–they live next to each other but in separate bedrooms, and they work together to keep the house in order. These chemicals evolved together as a defense system for the host plant to deter hungry bugs. When a bug (or a human like you!) chomps into some radish greens, you’re breaking up cells. The cells that contain glucoraphanin–called S-cells– and the cells that contain myrosinase are separate until the plant is damaged–then the boundaries are broken and the chemicals come in contact with each other. Only then can the chemical reaction that creates sulforaphane can begin!

 When microgreens are traditionally dehydrated, enzymes are being heated in the process and deactivated. Similarly, when microgreens are slowly frozen, large ice crystals can form and break the cells too early.

Interestingly, a healthy gut microbiome can also convert glucoraphanin to sulforaphane. So, if you hate raw veggies and you have a healthy gut, you may still be making sulforaphane after you cook them!

What are glucoraphanin benefits for health?

Glucoraphanin-rich foods can increase not only the amount of sulforaphane but its bioavailability in the body. Bioavailability is simply the amount of a chemical that actually makes it into your bloodstream. For healthy compounds like sulforaphane, you want it to have high bioavailability. 

Glucoraphanin becomes sulforaphane–and sulforaphane has been shown to have a bunch of powerful health benefits.

In a recent double-blind study, sulforaphane-containing broccoli sprouts were shown to enhance antiviral defense response. 

Sulforaphane can also reduce inflammation in vascular cells, potentially decreasing the risk for heart disease. Heart disease is still the #1 killer in the USA. In many studies, sulforaphane has been shown to beneficially adjust Nrf2 activation, which protects against cardiovascular disease (among many other disease).

Eating vegetables, especially cruciferous veggies that contain sulforaphane, isn’t only good for the body, it’s good for the mind. In studies in children with autism, sulforaphane was able to reduce the behavioral symptoms of autism. Sulforaphane is even thought to normalize brain chemistry. For this reason, researchers are studying it as a potential preventative medicine and therapy for schizophrenia.

Similarly, eating lots of nutrient-dense foods is shown time and time again to reduce the symptoms and onset of depression. Eat healthy and be happy!

What are glucoraphanin’s side effects?

Getting glucoraphanin from whole foods like broccoli and radish is unlikely to have any side effects if you eat a variable and healthy diet. 

However, lots of sulforaphane or glucoraphanin supplements are on the market nowadays. These supplements are generally considered to be safe except for mild side effects, however make sure you take the recommended dose (usually 1-2 pills a day).

Easily add broccoli to your diet

Hopefully now you understand why glucoraphanin powerhouses are so good for you. If you already eat your 5-9 servings of veggies a day, you’re well on your way to a healthy lifestyle. 

But if you need a little boost to get your veggies in, try our potent Broccoli Booster. It’s pure, organic, freeze-dried broccoli microgreens that you can add to any meal, or mix into your morning smoothie. One teaspoon serving of Booster is equivalent to half a cup of fresh broccoli microgreens!

Try sprinkling Booster with a little bit of shredded cheese onto a stir-fry of cruciferous veggies to max out your glucoraphanin and myrosinase. Or try the Beyond Microgreens team’s favorite...Booster mixed into an omelette made with organic eggs and fresh veggies!

Shop our potent Broccoli Booster to fill your diet with the nutrition it needs!

Carly Anderson Stewart, MSc. | Head of Biology and Education