How Broccoli Sprouts Switch Off Inflammation (Backed by 3 Major Human Trials)

From diabetes to everyday health, these studies prove sulforaphane can lower CRP, IL-6 and more – with results you can use starting today.

Inflammation is at the root of so many of today’s biggest health challenges – fatigue, stubborn weight gain, brain fog, joint pain, type 2 diabetes, even accelerated aging. And while short bursts of inflammation are part of your body’s natural defense system, when it lingers, it silently chips away at your energy, resilience, and long-term health.

That’s why I get so excited when research uncovers simple, natural ways to calm inflammation at its source. And over the past decade, one nutrient has stood out above all others: sulforaphane, the remarkable compound found in broccoli sprouts.

Now, I’m not talking about vague “superfood” claims. I’m talking about real, peer-reviewed human clinical trials showing measurable drops in inflammation markers like CRP, IL-6, and TNF-α. The kind of results you normally only see from prescription drugs.

In fact, three major studies – run in people with type 2 diabetes, in overweight adults, and in everyday healthy participants – have shown sulforaphane can switch off inflammation in a way that lasts. And here’s the best part: the most dramatic results came not from capsules or extracts, but from something as simple as eating a small handful of fresh broccoli sprouts each day.

So in this guide, I’m going to walk you through these three landmark studies, show you exactly what the researchers found, and most importantly, how you can put it into practice in your own life starting today.

What Sulforaphane Does in the Body

Researchers call sulforaphane a “master switch” because it activates the NRF2 pathway – your body’s built-in system for repair, detoxification, and defense. In simple terms, it doesn’t just fight one thing, it flips on hundreds of protective genes at once. That’s why scientists are so excited about it, and why its benefits reach far beyond inflammation.

• Detoxification [1] – Activates the NRF2 pathway, switching on detox enzymes that help your liver, kidneys, and cells flush out harmful compounds.
• Antioxidant Defense [2] – Boosts Phase II antioxidant enzymes (like GSTP1 and NQO1), neutralizing free radicals and protecting your cells from oxidative stress.
• Longevity & Cellular Repair [3] – Delays cellular aging by protecting mitochondria, reducing DNA damage, and supporting healthy cell function.
• Brain Health & Cognition [4] – Crosses the blood-brain barrier, reduces neuroinflammation, and protects neurons. Clinical research shows sulforaphane can improve cognitive function and even reduce symptoms in conditions like schizophrenia.
• Blood Sugar Control [5] – Suppresses liver glucose production and improves insulin sensitivity. In a human trial, daily broccoli sprout extract lowered fasting glucose by up to 71 mg/dL and improved HbA1c comparably to standard diabetes medication.

1. The First Clear Evidence (2012 human trial)

Back in 2012, researchers in Iran carried out the first rigorous human trial testing broccoli sprouts against inflammation. They enrolled 63 people with type 2 diabetes and gave them either a placebo or broccoli sprout powder at two doses – 5 grams per day (about 112 μmol sulforaphane equivalents) or 10 grams per day (around 225 μmol). The trial lasted just four weeks, but the results made history. [6]

Results at a glance:

• hs-CRP dropped 16–20% in the broccoli groups, while it rose 21% in placebo.
• IL-6 fell significantly in the higher-dose group.
• TNF-α trended lower but wasn’t significant.

This was the first clear proof that broccoli sprouts could directly reduce inflammation in humans.

2. Stronger and Longer Results (2017 Randomized, Double-Blind Study)

Five years later, Swedish researchers built on that work with a larger, longer trial. Ninety-seven people with type 2 diabetes were enrolled in a 12-week, randomized, double-blind study. Instead of powder, participants took a broccoli sprout extract delivering around 150 μmol sulforaphane daily. After the treatment phase ended, they were monitored for another 10 weeks to see if the effects lasted. [7]

Results at a glance:

• IL-6 dropped significantly during treatment and stayed below baseline even 10 weeks after stopping.
• CRP also dropped on treatment and, while it crept back up afterward, it remained lower than baseline.

This was the first time scientists observed a “reset effect,” suggesting sulforaphane may help the body maintain lower inflammation long after supplementation stops.

3. Everyday Food, Powerful Impact (2018 Controlled Dietary Intervention)

In 2018, a Spanish team asked a simple question: could fresh sprouts, eaten as food, deliver the same results as supplements? They recruited 40 overweight but otherwise healthy adults and asked them to add 30 grams (a small handful) of fresh broccoli sprouts to their diet each day for 10 weeks, then stop for another 10 weeks. Each serving provided about 117 μmol of glucoraphanin. [8]

Results at a glance:

• CRP dropped by about 59%.
• IL-6 dropped by about 55%.
• Inflammation levels stayed lower than baseline during the follow-up, even after stopping sprouts.

Food sources were even more powerful – inflammation markers were cut in half!

How to Put This Into Practice

The exciting thing about these studies is that they don’t just stay in the lab – they give us a clear roadmap for how much sulforaphane we need, and how to get it.

• If you’re using broccoli sprout powder: Aim for 5–10 grams per day. This was the exact dose used in the 2012 Iranian diabetes study that lowered CRP and IL-6. That’s typically 1–2 teaspoons daily, depending on the brand. Always check that the powder contains both glucoraphanin and myrosinase, or add a pinch of mustard seed powder to help with conversion.
• If you’re using extracts or capsules: Look for products standardized to around 150 μmol sulforaphane equivalents daily, the dose used in the 2017 Swedish trial. This form is the most consistent and convenient if you want a precise daily intake.
• If you’re eating fresh sprouts: Go for around 30 grams per day – roughly a small handful. This was the amount used in the 2018 Spanish trial, and it delivered the most dramatic results of all, cutting inflammation markers nearly in half. (Note: see the hot tip in the yellow box below!)

The bottom line: whether you prefer powder, supplements, or fresh sprouts, aim to consistently get the same levels that were shown to work in real human trials.

Not All Sulforaphane Supplements Are Made Equal…

Sulforaphane is one of the most powerful natural compounds ever studied – but here’s the catch: it’s also unstable. That means not all supplements deliver what they promise, so here’s what to look for:

1. Sulforaphane vs. Glucoraphanin
Most supplements don’t contain sulforaphane itself, because it breaks down quickly. Instead, they use glucoraphanin, its stable precursor. To actually produce sulforaphane, you also need the enzyme myrosinase. Without it, conversion in the body is low – only about 10%. With it, conversion can be as high as 70%. A massive difference.

2. What Clinical Trials Used
Human studies showing inflammation and blood sugar benefits used:

• 5–10 g/day broccoli sprout powder (2012 Iran).
• ~150 μmol sulforaphane/day from extract (2017 Sweden).
• 30 g fresh sprouts daily (2018 Spain).

When you’re looking at supplement labels, aim for products that get you into this same range.

3. What to Look For in a Supplement

• Glucoraphanin + Myrosinase – Best mimics what happens when you chew sprouts.
• Standardized sulforaphane yield – Some products test and guarantee actual sulforaphane output, not just glucoraphanin content.
• Transparency – Labels should clearly state the amount of glucoraphanin (ideally 30–100 mg per dose) and whether they contain myrosinase.
• What to Avoid – Products that just list “broccoli extract” or “broccoli powder” without specifying active compounds, blends that hide exact amounts, and low doses (under 30 mg glucoraphanin), which are unlikely to produce meaningful benefits.

How to Grow Broccoli Sprouts at Home

As I always say ‘fresh is best‘… and growing broccoli sprouts at home is actually really easy. I do intend to do a video in the near future, but this little step-by-step makes it pretty easy. Honestly, it’s hard to go wrong. They’re ready in less than a week, cost next to nothing, and give you the same levels used in clinical trials.

Here’s how to do it:

1. Soak the seeds – Place 2–3 tablespoons of broccoli seeds in a wide-mouth glass jar, cover with water, and soak overnight.
2. Drain and rinse – In the morning, drain off the water and rinse the seeds (ideally twice). Cover the jar with a mesh lid or sprouting lid and tip it upside down at an angle to drain.
3. Rinse twice daily – Morning and evening, give them a rinse with fresh water and drain again. Keep the jar tilted so excess water doesn’t pool.
4. Harvest in 5–7 days – When the sprouts are about 2–3 inches long and bright green, they’re ready. Rinse well and store in the fridge for up to 5 days.

Tips for success:

• Keep the jar in a spot with good airflow but out of direct sunlight.
• Wash your hands and equipment well to minimize contamination. We do not want mold.
• If you want to boost sulforaphane levels even further, lightly chop or blend the sprouts before eating – this helps activate more of the myrosinase enzyme.

How much to eat:
A small handful (about 30 g per day) is all it takes to match the Spanish study that cut inflammation markers nearly in half. Add them to salads, tuck into sandwiches, or blend into a green smoothie.

Final Word

When you step back and look at these three studies together, the message is clear: sulforaphane works.

• In people with type 2 diabetes, broccoli sprout powder lowered CRP and IL-6 in just four weeks.
• In a longer trial, an extract not only reduced inflammation but kept it down for weeks after stopping – almost like a reset button for the body.
• And in everyday adults, something as simple as a handful of fresh sprouts each day cut inflammation markers nearly in half.

That’s extraordinary. We rarely see natural foods or nutrients deliver this kind of result – and yet sulforaphane does it, consistently, across different groups and study designs.

And the best part? You don’t need to wait. Whether it’s growing your own sprouts at home, stirring a spoonful of powder into a smoothie, or using a carefully chosen supplement, you can start tapping into these same benefits today.

A handful of broccoli sprouts may seem small, but the science is showing us it could be one of the most powerful steps you can take to lower inflammation, protect your health, and support your long-term energy and vitality.

References

• 1. 1. Kubo, Eri, Bhavana Chhunchha, Prerna Singh, Hiroshi Sasaki, and Dhirendra P. Singh. “Sulforaphane Reactivates Cellular Antioxidant Defense by Inducing Nrf2/ARE/Prdx6 Activity during Aging and Oxidative Stress.” Scientific Reports 7 (2017): 14130. https://doi.org/10.1038/s41598-017-14520-8.
     2. Riedl, Marc A., Andrew Saxon, and David Diaz-Sanchez. “Oral Sulforaphane Increases Phase II Antioxidant Enzymes in the Human Upper Airway.” Clinical Immunology 130 (2009): 244–251. https://doi.org/10.1016/j.clim.2008.10.007.
     3. Ho, Emily, Jack D. Clarke, and Roderick H. Dashwood. “Dietary Sulforaphane, a Histone Deacetylase Inhibitor for Cancer Prevention.” Journal of Nutrition 139, no. 12 (2009): 2393–2396. https://doi.org/10.3945/jn.109.113332.
     4. Zhang, Xiaoying, et al. “Sulforaphane Supplementation Improves Negative Symptoms and Cognitive Function in Patients with Schizophrenia: A Randomized Controlled Trial.” Frontiers in Pharmacology 16 (2025): 1500123. https://doi.org/10.3389/fphar.2025.1500123.
     5. Dwibedi, Chinmay, Annika S. Axelsson, Birgitta Abrahamsson, Jed W. Fahey, Olof Asplund, Ola Hansson, Emma Ahlqvist, Valentina Tremaroli, Fredrik Bäckhed, and Anders H. Rosengren. “Effect of Broccoli Sprout Extract and Baseline Gut Microbiota on Fasting Blood Glucose in Prediabetes: A Randomized, Placebo-Controlled Trial.” Nature Microbiology (2025). https://doi.org/10.1038/s41564-025-01932-w.
     6. Bahadoran, Zahra, Parvin Mirmiran, Azadeh Hosseinpanah, and Fereidoun Azizi. “Broccoli Sprout Powder Could Improve Serum Triglyceride and Oxidative Stress in Type 2 Diabetic Patients: A Randomized Double-Blind Clinical Trial.” Journal of Functional Foods 4, no. 4 (2012): 837–841. https://doi.org/10.1016/j.jff.2012.05.001.
     7. Axelsson, Annika S., et al. “Sulforaphane Reduces Inflammation and Improves Glucose Control in Patients with Type 2 Diabetes: A Randomized Double-Blind Placebo-Controlled Trial.” Science Translational Medicine 9, no. 394 (2017): eaah4477. https://doi.org/10.1126/scitranslmed.aah4477.
     8. López-Chillón, María Teresa, et al. “Consumption of Broccoli Sprouts Reduces Oxidative Stress in Overweight Human Subjects.” Clinical Nutrition 37, no. 2 (2018): 471–480. https://doi.org/10.1016/j.clnu.2017.01.020.
     9. Okunade, Adeyinka, et al. “Supplementation of the Diet by Exogenous Myrosinase via Mustard Seeds to Increase the Bioavailability of Sulforaphane in Healthy Human Subjects after the Consumption of Cooked Broccoli.” Molecular Nutrition & Food Research 62, no. 8 (2018): 1700980. https://doi.org/10.1002/mnfr.201700980.