Sulforaphane and Longevity


Up Your Antioxidant Game with Broccoli, Cabbage, and Sprouts

I had to dig deep into clinical papers to get reliable information on Sulforaphane and longevity.

Most ‘scientific’ articles on this topic are shilling a supplement offer. It is hard not be biased when your income is linked to sales of the substance covered…

That aside, Sulforaphane is showing significant promise. Papers show that it is more than just an antioxidant. Sulforaphane has powerful anti-inflammatory effects and helps remove toxins from our bodies too.

Best of all, you’ll get plenty of it from cruciferous vegetables – the same type of food which feeds your gut microbiome.

This page covers Sulforaphane in depth, it is a topic overview – not medical advice. Oh, and the only thing I’ll try and ‘sell’ you is broccoli.

3D chemical structure of Sulforaphane

3D Structure of Sulforaphane: Image Credit

The Basics: What is Sulforaphane and What Are the Key Benefits?

Sulforaphane is a phytochemical (this simply means it is found in plants), more specifically an isothiocyanate.

IIsothiocyanates contain the building blocks of a powerful class of antioxidant compounds called glucosinolates. It is a powerful regulator of ROS – oxygen molecules missing an electron – which cause continual damage inside our cells. In addition, Sulforaphane has anti-inflammatory properties, it dampens pathways which trigger an overactive immune response.

Broccoli, broccoli sprouts, kale, brussels sprouts, and cabbage contain Sulforaphane. The amount varies with preparation method and specific sub-variants.

Multiple papers have measured the effects of Sulforaphane on cancers. This is outside of the remit of the Age Well Times – I have linked to papers at the end of this page for further information.

Sulforaphane, Antioxidant Qualities and NRF2

Before diving deep into the world of broccoli variants – let’s get biological.

The following three sections cover the reasons to top up your Sulforaphane, starting with reducing cellular damage through antioxidant pathways.

The NRF2 pathway is the topic of 1000’s of published papers. This controls antioxidant and anti-inflammatory responses. Both are core to cellular aging. It is the primary mechanism that gives Sulforaphane it’s antioxidant benefits.

Sulforaphane boosts NRF2 by blocking its breakdown. I watched an interview between the amazing Rhonda Patrick with Jed Fahey on this topic. Like everything at the cellular level, it is not as simple as ‘X triggers Y which does Z.’

Fahey said that as well as direct effects in the cell nucleus, NRF2 has a function in repairing broken proteins.

Here is a link to the full interview video (it will open up a new tab):

Oxidation and inflammation have roles in all the diseases of ageing, including the big killers. This means NRF2 is widely studied in both human and animal model trials.

This paper is an overview of targeting NRF2 in therapeutic papers:

Note that there are concerns that too much NRF2 could have damaging effects. This amounts considered appear to be way over the amount you’ll get from cruciferous vegetables or supplement use.

Sulforaphane and Longevity

Anti-Inflammatory Pathways of Sulforaphane

Sulforaphane’s anti-inflammation properties occur through regulation of multiple enzymes and transcription factors.

They include inhibition of a transcription factor called NF-KB. This factor triggers pro-inflammatory genes – inhibiting it will reduce the number of cytokines that signal to the immune system that help is needed. Sulforaphane reduces the production of ROS (reactive oxygen species) and helps modulate enzymes involved in the inflammatory response including COX-2, 5-LOX and iNOS.

Detoxifying Effects and Phase 2 Enzymes

Our bodies have a clever way of getting rid of toxic chemicals or drugs – adding a substance or molecule to it that reduces the harmful qualities.

Sulforaphane helps this process in specific cell types and for specific toxins.

The list of phase 2 effects include inducing / activating: Quinone reductase, Glutathione S-transferase, Heme oxygenase-1 and NAD(P)H.

As we age, our ability to detoxify is reduced. Sulforaphane can balance this, at least for specific toxins.

Cruciferous vegetables contain sulforaphane

Sulforaphane is Quickly Extracted

Up to 90% of sulforaphane is extracted via urine.

This varies individually, and by the way that sulforaphane is consumed. Direct consumption (in supplement form) results in faster excretion, compared to cruciferous vegetable consumption.

Questions arise from this; should you eat cruciferous vegetables multiple times per day? Is there one or more optimal times to consume them? How would this interact with diet and timing of meals?

Sulforaphane and Other Antioxidants: Overlaps or Complementary Effects?

Oxidisation is happening every moment of every day in our cells.

Without antioxidants, the damage would be too much to repair – aging and the diseases which stem from it will quickly follow.

Sulforaphane is one of many compounds with antioxidant qualities. Others include vitamins C and E, and beta-carotene. Let’s not forget naturally produced antioxidants – for example glutathione – which require amino acids such as glutamine from your diet.

Let’s take vitamin C as a starting point. Like sulforaphane, this triggers the NRF-2 pathway, attenuating oxidative stress. The missing part for me is what happens when multiple compounds are working through this pathway?

Are the effects cumulative? Do they both trigger the same benefits in an interchangeable way?

Quercetin also triggers NRF-2, raising a similar set of questions.

I’ll leave these meta-questions for another post. They apply to all longevity drugs and supplements.

There are reasons to take sulforaphane even if you are already benefiting from other antioxidants. Those are the immune suppressant and detoxification properties covered above.

Vitamin C and Sulforaphane

Back to Broccoli: How Chewing Precursors Creates Sulforaphane

Cruciferous vegetables are leafy greens. They include broccoli, broccoli sprouts, cabbage, Boc choi, brussels sprouts and kale.

I’m a big broccoli fan, though will be careful not to let my love of it (both cooked and raw in salad) cause bias in my writing!

These vegetables don’t contain Sulforaphane.

Instead, they contain two vital precursors to it. Glucoraphanin and the enzyme Myrosinase. When you chop or chew up your vegetables, these compounds are mixed – creating Sulforaphane.

Of all the vegetables listed, broccoli sprouts are the richest source of sulforaphane.

They are different to fully grown broccoli. The sprouts look like cress. By volume, broccoli sprouts contain 40x to 100x the level of Sulforaphane compared to the levels of regular broccoli.

Dosage: How Much Sulforaphane Do We Need?

It would be easy to believe that more is always better with sulforaphane.

Moving outside of the popular press (and those highly motivated supplement shills) to clinical trials, quickly shows that there is nowhere close to a consensus on the correct dose:

  • More than 2/3rds of studies have never tested different doses.
  • Doses used in animal studies spanned 4 orders of magnitude (the biggest was 10,000x the smallest).
  • Many animal studies injected chemically produced sulforaphane, rather than using oral precursors.

In fact, some of the clinical studies in cancer patients used broccoli soup. Cooked broccoli has significantly lower levels of the precursor compounds than raw, and both are low compared to broccoli sprouts. I’ll give credit where credit is due – the researchers measured Glucoraphanin content and picked the most abundant broccoli strains.

There is a toxic dose of sulforaphane. This is super-high compared to doses which have proven beneficial effects. Fatigue, stomach problems and diarrhoea have been recorded in mouse studies.

Studies of Sulforaphane continue

Cutting to the Chase: Should You Supplement Sulforaphane?

I prefer to get my Sulforaphane levels up naturally.

Broccoli, cabbage, and kale are packed with healthy nutrients, as well as fibre for your gut microbiome.

The NRF-2 Pathway is important, and clinical trials for its protective role show clear results. That same pathway is triggered by other antioxidants. Add anti-inflammatory and detoxification qualities and Sulforaphane is an all-rounder.

My one concern is the speed of extraction. Cruciferous vegetables are difficult to spread throughout the day. I’d like to see studies on how long the benefits (at a cellular level) are maintained before I carry brussels sprouts in my pockets for regular top-ups.

If you find the data compelling, your best source of Sulforaphane by far is broccoli sprouts, with raw broccoli in your salad better than cooked.

As someone that enjoys raw broccoli several times weekly in my lunch salads, I recommend putting your prejudices aside, and trying it!


I have added links to papers covering the role of Sulforaphane in oncology below. As this topic is outside of my remit, they are provided as a starting point for anyone wishing to dig into the medical science:


More Longevity Supplement Deep-Dives:


Mark’s Blog





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