Sulforaphane: The Broccoli Supplement Backed By Science

It was the trendy vegetable of the 1980s, but that didn’t deter George H W Bush, who famously said in 1990: “I do not like broccoli. And I haven't liked it since I was a little kid and my mother made me eat it. And I'm President of the United States, and I'm not going to eat any more broccoli.”

Although the green vegetable may not have been to the President’s taste, it’s trendy among his fellow Americans, who consume over five pounds of fresh broccoli yearly.

Consuming that much is doing them a world of good, not just because it contains a wealth of valuable vitamins, minerals, protein, and fiber but also because it’s home to an exceptional compound called sulforaphane with profound health-protective and healing properties.

If you share the late President’s disdain for the vegetable, that's not a problem; as we'll see, it can also be found in other vegetables and supplements.

Key Takeaways

• Mature broccoli and broccoli sprouts contain sulforaphane. This natural compound is good for the body because it has antioxidant properties and lowers inflammation.
  
• Sulforaphane is believed to help prevent numerous health issues, improve the strength of the heart, support balanced blood sugar, improve memory and liver health, and even prevent cancer.
  
• Sulforaphane is found in other members of the same Brassica family of cruciferous vegetables. You can also find it in broccoli sprout extract and broccoli seed supplements.
  

What is Sulforaphane?

Sulforaphane is a natural compound found in the Brassica/cruciferous family of vegetables. This includes broccoli and broccoli sprouts. But it's a little more complicated than that...

You see, this compound doesn’t exist as sulforaphane in these vegetables; but is born out of two other ingredients in the plant that combine together. It works like this:

There are natural compounds in cruciferous vegetables called glucosinolates, one of which is glucoraphanin. When you cut or bite into a head of broccoli, for instance, the cell walls of the vegetable get broken down and – if the broccoli is raw or lightly cooked – an enzyme called myrosinase is released. The enzyme combines with glucoraphanin to create sulforaphane and all its incredible health benefits.

In fact, these benefits are so profound, leading cardiologist, research scientist, and best-selling author, Dr. John D. Day, writes that “sulforaphane may be the best way to reverse and prevent almost every medical condition.” [1]

That’s a bold statement. Let’s see why he makes such a huge claim.

The Amazing Health Benefits of Sulforaphane

Sulforaphane helps the body in many ways but one of its key properties is the ability to activate a “master regulator” protein called Nrf2. It’s given that name because Nrf2 is no ordinary protein; it’s a transcription factor, meaning it has the power to turn genes “on” and “off”.

Nrf2 can “turn on” up to 200 genes responsible for multiple processes, including cellular repair, antioxidant protection, detoxification of environmental carcinogens, immune response, and more. [2]

So sulforaphane, by activating Nrf2, can help the body maintain health and fight almost every health challenge thrown in its path.

Let’s have a look at the properties of Nrf2 in more detail.

Antioxidant, Detoxifier, and Inflammation Fighter

When the body needs to respond to oxidative stress (excessive free radicals) or needs to detoxify environmental toxins, it calls upon Nrf2. This boosts antioxidant and detoxifying (phase 2) enzymes to protect organs and tissues from harm.

Nrf2 also has a key role in reducing chronic low-grade, simmering inflammation. This pervasive feature of aging causes tissue degeneration, premature aging, and is a characteristic of most, if not all, age-related diseases.

A safe remedy that fights chronic inflammation would be a big deal, and that’s where sulforaphane comes in. This natural compound targets important pathways involved with inflammation, one of which is Nrf2. Activation of this pathway not only boosts antioxidant and detox enzymes but also lowers inflammation.

That sulforaphane can activate Nrf2 is profound, but its abilities go even further.

Another pathway, and key inducer of inflammation, is the protein NF-κB. Sulforaphane helps inactivate this pathway by dampening down a whole host of pro-inflammatory proteins and enzymes involved with inflammation. [3]

Now let’s look at how sulforaphane helps you tackle specific health problems.

Helps Prevent Cancer

Science shows populations who eat diets rich in broccoli and other vegetables in the Brassica family have lower rates of cancer compared to those who don't eat these vegetables. These studies looked specifically at rates of cancers of the breast, lung, prostate, pancreas, and colon, among others.

But how many Brassica vegetables did they eat? Studies show that eating three to five servings of Brassica vegetables a week can lower the risk of developing cancer by 30 percent to 40 percent.

While that may seem like a lot of broccoli, even eating one portion of Brassica vegetables each week can lower your risk of cancer—especially oral cancers (pharynx and esophagus), and cancers of the colon, breast, and kidney. [4]

As well as its potential in cancer prevention, sulforaphane may also have a place in cancer treatment. The type of cancer with the best clinical evidence for its use is prostate cancer.

Two studies of men taking daily sulforaphane supplements for five or six months found less increase in PSA - a marker of tumor progression - than in the placebo (sugar pill) group. And two others found positive changes when looking at other markers of prostate health. [5]

While the findings in prostate cancer research are encouraging, they’re still limited and sulforaphane remains an unapproved, experimental treatment. Patients should consult with their doctors before considering broccoli supplements.

Promotes Heart Health

In laboratory studies in mice, scientists demonstrated the value of either sulforaphane or broccoli sprouts in protecting against heart disease. [6] These plant compounds can:

1. Protect arteries and blood vessels against plaque
2. Reduce inflammation in stiff, hardened arteries
3. Bring blood pressure into healthy balance
4. Protect the heart from damage in the event of a heart attack
5. Lower the risk of dangerous blood clots

Human studies show people consuming the most cruciferous vegetables have a whopping 31 percent reduced risk of death from cardiovascular disease. And those consuming glucosinolate-rich broccoli led to a marked reduction in LDL “bad” cholesterol. [3]

Encourages Balanced Blood Sugar

Many trials show the blood chemistry of patients with Type-2 diabetes improves with broccoli sprouts.

In one, patients were split into two groups to eat either broccoli sprouts or placebo. After three months, the blood sugar readings in the broccoli sprouts group were 10 percent lower than the placebo group, all without the typical side effects seen with blood sugar-lowering drugs.

In other human diabetes trials, those eating broccoli sprouts increased HDL “good” cholesterol, decreased oxidative stress, lowered triglycerides (blood fats), reduced CRP (a marker of inflammation), and improved insulin resistance. [1]

Protects Memory

Your brain possesses its own “fertilizer” protein called BDNF which protects and repairs brain cells, helps it develop new connections, and keeps your brain sharp. So it's no surprise that you want to increase your levels of BDNF any time you can. Sulforaphane has been shown to do just that.

In one study, the researchers wrote that “sulforaphane has the potential to prevent neuronal disorders such as Alzheimer's disease” by enhancing the expression of BDNF in the brain. [8] Other rodent studies show that sulforaphane can help protect against brain damage, reduce brain inflammation, preserve memories, and improve cognitive performance.

A Harvard study of 15,000 aging women over 27 years found those eating the most cruciferous vegetables had less cognitive decline compared to those eating the least. [9] This result isn’t surprising when you consider the power of sulforaphane to boost glutathione. This is the body’s master antioxidant, and it plays a major role in detoxifying the body, protecting against inflammation, and promoting DNA repair.

The power of sulforaphane to protect the brain was demonstrated by scientists at Johns Hopkins Medicine. They found after just seven days, broccoli sprout extract increased glutathione in the brain of human volunteers by an incredible 30 percent and by 25 percent in the hippocampus alone, a key memory area of the brain. [7]

Fights Aging

These vegetables may well help you live longer because of the previously described roles of Nrf2, which is why this protein is implicated in aging and longevity. By protecting cells from free radicals, inflammation, and the many other harmful processes that wear cells out over time, Nrf2 can prevent cells from prematurely aging and therefore help us live longer.

Researchers believe that since Nrf2 declines with aging, propping up this protein could potentially increase lifespan. For instance, the exceptionally long-lived naked mole rat shows enhanced Nrf2 compared to shorter-lived rodents.

Because of the profound influence of Nrf2 in so many aspects of aging, some scientists even propose its “master regulator” catchphrase should be extended to “master regulator of the aging process”. Since sulforaphane activates Nrf2, it’s likely to fight aging as well. [10]

And the good news doesn’t stop there because sulforaphane can also stimulate proteasomes.

Proteasomes are the cells’ garbage disposal system, clearing out old and damaged proteins that would otherwise clog up cells and prevent them from functioning normally. With aging, however, proteasome activity declines, and this contributes to disease. Results from several studies suggest proteasome activity and longevity are linked; therefore, sulforaphane, by its ability to stimulate proteasomes, has a starring role in healthy longevity. [11]

Supports Liver Health

In animal experiments, sulforaphane protects against a wide variety of liver diseases caused by toxic chemicals, alcohol, and high-calorie diets. These findings led to a human trial in men with fatty liver disease.

Those taking a sulforaphane-rich broccoli sprout extract saw an improvement in liver function compared to the placebo group. The researchers concluded that broccoli sprout extract “is likely to be highly effective in improving liver function through reduction of oxidative stress.” [12]

And in another human trial of healthy, middle-aged adults with the high-normal liver marker ALT, broccoli sprout supplements enriched with glucoraphanin improved ALT levels at 24 weeks compared to placebo supplements. [13]

Huge Potential in Multiple Conditions

Sulforaphane, broccoli sprouts, or broccoli extracts have been tested in Petri dishes and rodents for many more conditions than discussed above. Most had positive outcomes which led to several small human clinical trials. The results of these trials suggest that sulforaphane, broccoli sprouts, or broccoli extracts could be valuable in the following conditions because they were shown to:

• Damp down skin damage caused by UV radiation
• Improve behavioral symptoms in autism
• Protect the stomach lining from damage caused by H. pylori infection
• Relieve constipation
• Reduce the impact of air pollution in allergies and asthma
• Lower inflammation in healthy overweight people
• Positively affect joint tissue in patients with knee osteoarthritis [14]

How To Increase Your Levels of Sulforaphane

Choosing Sulforaphane-Rich Foods

The following foods contain glucoraphanin, the precursor to sulforaphane. However, plants have extremely variable levels and typical cooking temperatures above 60° start to inactivate myrosinase, so it’s best to eat these vegetables raw or only lightly steamed. Broccoli sprouts contain by far the most glucoraphanin, with levels up to fifty times more concentrated than mature broccoli. The sulforaphane-rich plants include:

• Broccoli sprouts
• Broccoli
• Brussels sprouts
• Mustard greens
• Watercress
• Turnips
• Garden cress
• Arugula
• Cauliflower
• Kale
• Cabbage
• Bok choy
• Collard greens

Ingesting sulforaphane from these vegetables is preferable because they also contain many other nutrients. For instance, broccoli contains a wide variety of vitamins, minerals, and phytonutrients. Just one cup provides more than 100 percent of our daily requirement for vitamin C and vitamin K, and it’s also a good source of vitamin A, folate, potassium, protein, and fiber.

Some people avoid sulforaphane-rich vegetables like cauliflower and broccoli because they can cause gas. However, sulforaphane can also be obtained from supplements.

Supplementing with Sulforaphane

Over-the-counter supplements containing broccoli sprout extracts, seeds, or broccoli sprout glucosinolates are available. They can even be found in the form of tea and coffee.

Some products are standardized to contain a minimum amount of glucoraphanin. They may not contain myrosinase because myrosinase-like activity occurs in the gut microbiome, so some of the glucoraphanin will be converted to sulforaphane there. The amount will vary from one person to the next. Other supplements contain both glucoraphanin and myrosinase, obtained from mustard seed powder.

As for dosage, there’s no standard amount; it varies from one supplement provider to another. Keeping to the recommended dose on the label shouldn’t present any problems, but some people may have mild side effects such as heartburn or an upset stomach. If you’re taking medication, speak to your doctor if you have concerns.

Summary

Broccoli, and especially broccoli sprouts, produce high concentrations of sulforaphane when eaten. The principal benefit of this compound is its ability to switch on a protein called Nrf2. This triggers the release of detoxifiers and antioxidants, inhibits inflammation, and promotes cellular protection. As these processes are vital to every aspect of health, sulforaphane has been shown to have protective and healing roles in multiple conditions. Sulforaphane can be obtained from broccoli and other cruciferous vegetables or can be taken as a supplement.

Frequently Asked Questions

What are the benefits of taking broccoli supplements?

A broccoli supplement is ideal for people who don’t eat cruciferous vegetables or only like the ones they do eat that are well-cooked, as this depletes or destroys the active enzyme, myrosinase, making sulforaphane unavailable to the body. A good quality broccoli supplement from a reliable brand guarantees getting a regular dose each day.

What does sulforaphane do to the body?

It’s a potent inducer of phase II detoxification enzymes which eliminate many types of environmental toxins such as UV rays from the sun, vehicle exhaust, cigarette smoke, and air pollution. It also triggers the production of antioxidants that protect against cell-damaging free radicals, and in addition, it cools down inflammation. Since Nrf2, the protein it activates, has important roles in metabolism, mitochondrial (energy) production, immunity, cell growth, and more, the benefits of sulforaphane to the body seem almost limitless.

What are the downsides of sulforaphane?

Derived from food, there are no downsides, apart from those that don’t enjoy cruciferous vegetables. But in supplement form it could cause minor problems in sensitive people such as heartburn, burping, or indigestion even at the recommended doses.

What are broccoli sprouts?

They are essentially baby versions of the mature plant. Several days after broccoli seeds are planted, the first green shoots to emerge are the sprouts. Fresh broccoli sprouts don’t taste a lot like broccoli and are good to eat raw, so are ideal for those that aren’t a fan of the full-grown version. Although small, they punch well above their weight, containing 20 to 50 times more sulforaphane than mature broccoli.