Sulforaphane is amazing. Sulforaphane is also the reason that we make juice from broccoli sprouts. Here we tell you more about sulforaphane and some of reasons why over 1900 research studies have been published on it.
Although you may not have heard of it, if you’ve ever eaten raw broccoli or broccoli sprouts, you eaten sulforaphane! No, we all know that broccoli is good for us, but what you may not know is why it’s actually sulforaphane that should be getting your attention.
Let’s find out more about sulforaphane and how it is uniquely intertwined with broccoli and broccoli sprouts.
What is Sulforaphane?
Sulforaphane is a compound found in plants. Sulforaphane belongs to a group of compounds called isothiocyanates.
Sulforaphane is the main isothiocyanate that comes from broccoli.
How is Sulforaphane Made?
Sulforaphane doesn’t exist in the growing plant but is formed by a chemical reaction when the plant is cut or chopped and its cell walls are broken.
First, let’s start where it all begins. If you don’t want a detailed explanation jump straight to our user-friendly graphic (link to diagram):
What is Myrosinase?
Myrosinase is an enzyme that is found naturally in broccoli, cauliflower, cabbage, mustard and cress. Plants use myrosinase with its co-factor (catalyst) ascorbate in conjunction with glucosinolates as part of their natural defence system against herbivores. When an insect starts to eat the plant, this breaks the cell walls which releases myrosinase. The myrosinase then combines with glucosinolates, to form substances which can be naturally toxic to herbivores.
What are Glucosinolates?
Glucosinolates are the compounds in cruciferous vegetable plants that are responsible for the strong smell.
What is Glucoraphanin?
Glucoraphanin is a special glucosinolate that is found in broccoli, cauliflower and mustard.
Glucoraphanin is special because it produces sulforaphane.
How Does Glucoraphanin Produce Sulforaphane?
Glucoraphanin is inert (does not react) in the vegetable as it grows naturally, BUT when the vegetable cell walls are broken, the plant’s natural defence system kicks in. Not so good for insects and herbivores, but very good for us, since this is when the magic happens.
As the vegetable is chewed or juiced, glucoraphanin is released and comes into contact with the enzyme myrosinase and it’s co-factor, ascorbate (Vitamin C) which is naturally present in raw (uncooked) vegetables. This special reaction forms sulforaphane, which is absorbed quickly into the blood.
How is Sulforaphane Made: A Summary
1. Vegetables containing glucoraphanin (eg broccoli or broccoli sprouts) are chopped, chewed or juiced.
2. This releases the enzyme myrosinase and glucoraphanin, along with ascorbate (Vitamin C).
3. Sulforaphane is made when myrosinase, its co-factor ascorbate (Vitamin C) and glucoraphanin combine.
4. If the vegetable is heated, the ascorbate (Vitamin C) is destroyed and sulforaphane cannot be made since the co-factor to the reaction is missing.
See diagram below
Who Discovered Sulforaphane?
Sulforaphane was discovered in 1992 by Paul Talalay the Director of the Laboratory for Molecular Pharmacology at the Johns Hopkins School of Medicine and his co-worker, Jed Fahey. The findings made front page news on The New York Times and have been widely reported such as this news article since then.
Paul Talalay and Jed Fahey’s discovery more than 25 years ago inspired many other scientists to investigate sulforaphane. To date, there have been more than 1900 research studies conducted on sulforaphane. One of the biggest advocates for sulforaphane is Dr Rhonda Patrick who is a scientist with a Ph.D. in biomedical science and who has done extensive research on aging, cancer and nutrition. Here you can watch her interviewing Jed Fahey on sulforaphane.
Sulforaphane, glutathione and Nrf2
The Nrf2 pathway is not well known but deserves a lot more credit than it gets! This is because it is actually the key to your immune system, your rate of ageing and – importantly – your antioxidant levels.
It has been called many things including:
The Nrf2 pathway results in the production of glutathione plus an enzyme called glutathione S-transferase (GST) that allows glutathione to bind with toxins (such as artificial chemicals in foods and drugs). This process enables the body to eliminate potentially harmful and toxic compounds. Nrf2 activation is an important way to detox.
However, the Nrf2 pathway can fail as we age, meaning our cellular defence (immune system), detox mechanism and antioxidant production don’t work as well.
Sulforaphane has been shown to kick start the Nrf2 pathway. Read more about Nrf2 on our health blog.
How Does Sulforaphane Work?
Since 1992, when the John’s Hopkins Institute published their discovery about sulforaphane and it’s effects on the body’s natural defences against oxidative stress, inflammation and DNA damage, there have been over 1900 research studies on how sulforaphane works. Although we are not permitted to tell you what sulforaphane can do, we can say that the research studies include: sulforaphane and cancer and carcinogens, sulforaphane and autism, sulforaphane and diabetes. Take a look for yourself!
There are many more uses than are permitted to list here, so we suggest you google, but here are those we can mention!
Sulforaphane and Antioxidants
Did you know that sulforaphane is by far the best way of getting antioxidants?
Sulforaphane does this because it stimulates the body to create its OWN antioxidants. It does this by correcting the Nrf2 pathway.
What’s clever about the Nrf2 pathway is that it generates exactly the right amount of antioxidants that you need, at exactly the right time. When the Nrf2 pathway is working properly, there is need for you to rely on antioxidants from what you eat. As you know, it’s difficult to get enough antioxidants from diet alone plus they can easily be destroyed by heat.
However, problems start when the Nrf2 pathway stops working properly, which it does especially as we get older. Read more about Nrf2 on our health blog… This is where sulforaphane steps in to save the day! Sulforaphane kick starts the body’s own antioxidant factory. Sulforaphane helps to ensure that you get the antioxidants that you need, when you need them.
Sulforaphane and Weight Loss
A recent study showed that sulforaphane helped to create more brown fat cells, important because leaner adults tend to have a higher ratio of brown fat to white fat cells.
Why Brown Fat is Better than White Fat
Brown fat is considered to be more like muscle than like white fat. What’s important is that activated brown fat actually burns white fat. This can lead to fat loss. A study confirmed that sulforaphane led to 20% loss of visceral fat in rats. You can read a summary of the study and or the original research study.
Sulforaphane and Detox
Sulforaphane helps the body to generate antioxidants by correcting the Nrf2 pathway. What you may not realise is that it also assists the body with detoxification. We go into detail on our health blog.
Sulforaphane May Slow Ageing
In order to counter what we put down to ‘the signs of ageing’, many of us take anti-oxidants not realising that this is really only a ‘sticking plaster’ approach. It’s a bit like pouring more oil into a car that has dirty oil: the car will keep going with more oil but can never perform as it was when brand new with clean oil in the engine.
The real issue is that our anti-aging mechanism – the Nrf2 pathway – has stopped working properly and we just need to find a way to get it to work again.
What we need to do is to find a way to get the body’s own antioxidant factory working properly again.
There are a few ways that we can do this and make some improvements:
This goes someway to explaining why those of us who exercise and eat well, tend to look younger and are healthier. Despite this, we can still have health problems and what we need to be doing is taking something that is really effective at restarting the Nrf2 pathway. What Dr Jed W. Fahey discovered after spending years researching sulforaphane is that sulforaphane is “The most potent activator of Nrf2 to be found naturally.” Dr Jed W. Fahey
Sulforaphane is by far the Best Way to Kickstart our Own Antioxidant Factory. Read more on our health blog…
Dr Rhonda Patrick on Sulforaphane:
Broccoli Sprout Juice – The Best Source of Sulforaphane?
Is broccoli sprout juice the best source of sulforaphane? This is a very good question as there is more than one source of sulforaphane!
Here we guide you through the choices:
Scroll down for graphic
Broccoli vs other Cruciferous Vegetables?
There are over 120 different glucosinolates (the compounds responsible for the smell in cruciferous vegetables)
Glucoraphanin (the pre-cursor to sulforaphane) is the main glucosinolate in broccoli.
Broccoli is the richest source of glucoraphanin of all cruciferous vegetables.
Raw Vegetable Benefits
As soon as any vegetable is heated to over 45 degrees Celsius (113 degrees Fahrenheit), the enzymes break down. Heating also destroys the vitamin C content. This means if you can eat raw vegetables you’re getting mouthfuls of nutrients that your body can digest properly. Make sure that you chew the vegetable well to break down the cell walls or, better still, cold-press juice it.
Raw Broccoli Benefits
Broccoli is high in many nutrients, including enzymes, vitamin C, vitamin K, potassium and iron. Raw broccoli contains about 90% water, 7% carbohydrates and 3% protein (more than many vegetables) and virtually no fat. The advantage of eating raw broccoli is that the enzymes are preserved meaning the enzymes can digest the plentiful nutrients within broccoli. 100g raw broccoli also provides more than the recommended daily amount of Vitamin C although cooking broccoli destroys much of this valuable vitamin C. Why not make a raw broccoli salad with broccoli and some of your other favourite raw vegetables? Pour over extra virgin olive oil and balsamic vinegar and season with Himalayan pink salt and black pepper. Add some garlic, paprika and coriander for taste. If you leave raw broccoli salad to marinade for a day, the vegetables soften and soak up the flavours in the oil.
Sulforaphane from Raw or Cooked Broccoli
Is it better to get sulforaphane from raw or cooked broccoli?
As we have seen, heating any raw vegetable, including broccoli destroys the enzymes, so cooked broccoli cannot provide any sulforaphane since the myrosinase has been destroyed and cannot convert the glucoraphanin into sulforaphane.
Raw broccoli is a much better source of sulforaphane than cooked.
Benefits of Sprouts
Sprouts are low in calories and rich in enzymes and other micro-nutrients. They’re also relatively easy to grow at home although watch out for mould since growing conditions require warm damp conditions. When seeds are soaked, the enzyme inhibitors are released and along with it the nutrients stored in the seed. Despite being very high in nutrients, such as Vitamin A, B, C and E, sprouts are very low in calories and natural sugars so offer perfect source of nutrition for those concerned about their weight.
Sulforaphane Levels in Broccoli Sprouts vs Mature Broccoli
Broccoli sprouts contain 100 times as much glucoraphanin compared with the mature plant.
Broccoli sprouts are 100 times better at providing sulforaphane than the mature broccoli.
Cold-pressed juice is juice extracted from fruit and vegetables at low temperatures, using masticating juicer. The juicing takes time and must be done gently in order not to generate heat (that would destroy the enzymes and nutrients). The benefit of cold pressed juice is that it contains enzymes and nutrients in a highly available form. The nutrients within the juice can be more easily digested when the enzymes in the juice are still intact. The disadvantage is that all the fibre has been removed (the fruit/vegetable pulp) meaning that it is not advisable to make cold-pressed juice a big proportion of daily intake. However, it is very useful to transfer specific nutrients into the body in a very efficient way. Most of the cold-pressed juice you buy in the shops is heat pasteurised in order to extend the shelf life. The only juice that has not been heated is cold-pressed juice that is made at home, pressed fresh to order or preserved using High Pressure Processing also known as HPP.
Broccoli Sprout Juice
Broccoli Sprout juice is made from broccoli sprouts. At Vegus Juices, we use only 4-5 day old sprouts to maximise the amount of sulforaphane obtained, since this starts to decrease as the sprouts age. The sprouts are grown in nutrient rich media: We at Vegus Juices use special mineral rich spring water. The sprouts must be grown at the perfect temperature and light conditions to maximise the nutrients and avoid growth of mould. When the sprouts are ready, they are washed and juiced. The juicing releases the myrosinase which combines immediately with glucoraphanin to produce sulforaphane. The cold-pressed juice is then treated with high pressure processing which increases the amount of sulforaphane, locks in the nutrients and keeps the juice fresh. Natural cold-pressed, unheated broccoli sprout juice also contains co-factors, such as Vitamin C complex, that are used to assimilate the sulforaphane to its maximum potential.
Sulforaphane Amount Released by Eating Broccoli Sprouts vs Drinking Broccoli Juice
Is it better to chew or cold-press juice broccoli sprouts?
Juicing broccoli sprouts breaks down all the cells, releasing the maximum amount of glucoraphanin. In contrast, we rarely chew our foods to liquid.
Be sure that if you are growing your own sprouts and juicing them, you cold-press the juice. It is important to ensure that the glucoraphanin, the enzyme myrosinase plus the co-factor Vitamin C (ascorbic acid) are preserved during the juicing process. So cold-press at low temperatures but never freeze the juice or sprouts for that inhibits the enzyme activity.
Juicing broccoli sprouts is the most effective way of producing sulforaphane.
Sulforaphane and High Pressure Processing
A recent study showed that HPP actually ***INCREASES*** the amount of sulforaphane, the active ingredient in broccoli sprouts.
How High Pressure Processing Works
HPP = High Pressure Processing and is an emerging technology used in the food industry to preserve foods at extremely high pressure yet low temperature without changing the taste, nutrients or appearance.
Why is High Pressure Processing Better than Heat Processing?
Fruit and vegetables in their natural state contain enzymes. Enzymes are important because they help break down the food you eat into usable components. This means that the body does not have to produce enzymes in order to perform the digestive function.
Heating any food or drink over 45 degrees Celsius (113 degrees Fahrenheit) denatures (destroys) these enzymes. The heat changes their structure and makes them inactive.
The enzymes occurring naturally in cold-pressed fruit and vegetable juices are killed off during heat pasteurisation along with a good proportion of the water soluble nutrients such as Vitamin C. This means not only are there less nutrients than with non-heated juice, the nutrients remaining cannot easily be used your body. This means that instead of being fully digested, the juice is processed in the gut by fermentation with sugar, leading to indigestion, bloating and constipation.
In contrast, High Pressure Processing preserves the nutrients and can slightly increase enzyme activity (by 1-4%). Cold-pressed juice that has been high pressure processed still has both the enzymes and nutrients fully intact. This means your body can benefit from all the goodness from the juice as if it were freshly cold-pressed at home.
High Pressure Processing Increases the Amount of Sulforaphane
A study on broccoli sprouts found that:
- Gentle warming sprouts (60 degrees C) releases 69% of available isothiocyanates including sulforaphane. BUT….
- Subjecting broccoli sprouts to high pressure processing (HPP), releases much more sulforaphane; a huge 85% of available isothiocyanates including sulforaphane.
If you want to get the most sulforaphane from your broccoli sprouts, make sure you juice them and subject them to HPP High Pressure Processing.
Or you could simply open a bottle of Vegus Juices Broccoli Sprout juice and know that in each 40ml you’re getting 100 micromols of sulforaphane, which is 2.5 times the recommended dose.
The best source of sulforaphane is HPP treated broccoli sprout juice.
Sulforaphane supplements contain glucoraphanin and myrosinase or simply glucoraphanin on its own. The average tested bioavailability of sulforaphane supplements ranges from 10% to 30%, pretty low. Bioavailability scores are based on Jed Fahey’s research at the Johns Hopkins Institute. The low bioavailability rates are unsurprising since the sulforaphane supplements are either missing one of the main components in the reaction to make sulforaphane (eg the enzyme myrosinase) or the essential co-factor (Vitamin C, ascorbic acid).
Natural is always best because sulforaphane needs co-factors that are naturally present in cold-pressed broccoli sprout juice in order to be digested. However if you cannot get hold of broccoli sprout juice, we take a look at the other synthetic sources of sulforaphane.
A synthetic sulforaphane has been manufactured and called the ‘Broccoli Pill’ This is a misnomer since it is doesn’t actually contain actual broccoli. As with any synthetic supplement, there may be side effects. The absorption rate of synthetic sulforaphane is significantly less than the absorption rate of sulforaphane from natural broccoli sprouts. This may be because sulforaphane needs co-factors or other phytochemicals that are naturally present in living broccoli sprouts to be metabolised efficiently.
Broccoli extract is made from powdered dehydrated broccoli. They have some nutritional value, but deliver virtually no sulforaphane since there is 100 times less glucoraphanin (the pre-cursor to sulforaphane) than broccoli sprouts.
Broccoli Sprout Extract
This sounds like a much better idea than broccoli extract until we learn that the extract is prepared by dehydrating broccoli sprouts. The heating action greatly reduces the amount of sulforaphane in the remaining extract since both the enzyme myrosinase and Vitamin C are destroyed by the very heat that is needed to dehydrate the liquid present in the sprouts.
Broccoli Seed Extract
Broccoli seeds are naturally very high in glucoraphanin which is the main source of sulforaphane. This sounds perfect until we take a closer look at the structure of seeds. Enzyme inhibitors are present in all nuts and seeds until they are soaked and this releases the enzyme inhibitor so they can germinate. This is a natural defence mechanism employed by the plant to ensure their seeds (or nuts) are carried sufficient distances in order to ensure effective propagation. Broccoli seed extract is based on ground broccoli seeds which contain enzyme inhibitors and which makes the myrosinase inactive, therefore sulforaphane cannot be made.
Broccoli Sprout Powder
As its name suggests, broccoli sprout powder is made from broccoli sprouts. Great! That sounds a perfect solution. However, the drying process that is needed to turn the broccoli sprouts into powder is what makes this supplement not so great. As you know, heat is needed to remove the liquid from the sprouts, but, what happens when you heat an enzyme? It is destroyed. And what happens when you heat Vitamin C (the co-factor needed to make sulforaphane)? It is destroyed. So the potential for broccoli sprout powder to make sulforaphane is greatly reduced.
Sulforaphane Recommended Daily Amount
There is no recommended daily amount for sulforaphane although participants in different research studies were given daily amounts from 10 to 20 micromols sulforaphane.
Sulforaphane Possible Side Effects
In general broccoli sprouts and broccoli sprout juice are safe to consume and any side effects are few and not serious. The most common side effect is gas, common to all cruciferous family vegetables. Side effects from sulforaphane supplements (ie, pills and extracts of sulforaphane, broccoli seed, etc) can include constipation and diarrhoea.
Pregnancy and Breast Feeding
Broccoli sprout juice is a natural product but, as with any food and drink, it is advisable to consult with a doctor before consumption of this or of manufactured sulforaphane supplements.
Compatibility with Other Medicines
There are no known contraindications of broccoli sprout juice as it is a natural product. However, is advisable to consult with a doctor before consumption of sulforaphane supplements.
Sulforaphane Where to Buy
If you would like to buy sulforaphane we recommend going for the most natural source you can find. Sulforaphane can be sourced in supermarkets as broccoli sprouts and then juiced at home. The best source of all is HPP treated broccoli sprout juice which is available in retail outlets and also direct from our shop.
Or if you prefer a sweeter taste, try our new Broccoli Sprout + Beetroot juice and get 50 micromols sulforaphane, or 125% of the recommended dose.