Microgreens, Broccoli Sprouts, and Sulforaphane
What the research says, and how to get it without a sprout jar
Hey folks, Kevin here.
Years ago I made a video on microgreens, broccoli sprouts, and sulforaphane. People still find it. The science has not gone stale, so this is the article version, for anyone who wants the studies and the steps in one place.
We do not grow broccoli sprouts or microgreens anymore. On this homestead there is always something else that has to get done, and the jars lost the argument. We take Avmacol Extra Strength instead. The inexpensive home method is still here, because it works, and because a lot of you have more time for a jar than we do right now.
What the sprouts are actually for
Broccoli does not store much sulforaphane ready-made. It stores glucoraphanin, and an enzyme, myrosinase, kept apart in the cell. Sulforaphane forms when you break the cells and the two meet. Chop, chew, or blend. The enzyme converts the precursor within minutes. You absorb the sulforaphane.
Its main studied job is not to act as an antioxidant in the bowl. It activates Nrf2, which turns on the body's own defense and detox genes. That is the mechanism the Johns Hopkins group has followed since the sprout paper (1).
Heat kills myrosinase. Cooked broccoli, eaten alone, yields little sulforaphane. Gut bacteria can convert some leftover glucoraphanin. They do it less reliably than the plant enzyme.
Fahey and colleagues measured that in people. Glucoraphanin without active plant myrosinase converted at about 10%. Fresh sprouts or seeds, with the enzyme still alive, were about three to four times more bioavailable, in the mid-30s to about 40% (2).
Why sprouts beat a head of broccoli
In 1997, Fahey, Zhang, and Talalay reported that three-day-old broccoli sprouts held 10 to 100 times more glucoraphanin than mature broccoli, gram for gram (1). That is still the paper the field cites.
Microgreens are the next stage: the seedling cut once the first leaves open, usually 7 to 21 days after planting. Sprouts are younger. You eat the germinated seed, root and all, after a few days.
Xiao and colleagues at the USDA measured vitamin C, vitamin E, vitamin K, and carotenoids in 25 microgreens and compared them with mature leaves (3). The cotyledon leaves were denser in those nutrients. The spread between varieties was wide. In that set, red cabbage led vitamin C, cilantro led carotenoids, garnet amaranth led vitamin K, and green daikon radish led vitamin E. The USDA news summary put the average around five times the mature plant (4). That is a selected-vitamin comparison, not a claim that a tray replaces a meal.
What the human trials show
The cleanest trial is still Qidong. Egner, Kensler, Fahey, Talalay, and colleagues randomized 291 adults for 12 weeks to a broccoli-sprout beverage or a placebo drink. The sprout drink raised urinary excretion of benzene by 61% and of acrolein by 23%. Crotonaldehyde did not move (5). That is excretion of pollutants, not a cancer-rate result. It is the strongest human evidence that a sprout preparation can turn up this pathway in daily life.
The autism trial people usually mean is Singh and colleagues, 2014. Forty-four young men, ages 13 to 27: 29 on sulforaphane from broccoli-sprout extract, 15 on placebo, 18 weeks. Parent and clinician behavior scores improved on sulforaphane and drifted back when the capsules stopped (6). One site. Not a cure.
A 2026 randomized crossover tested mustard-seed myrosinase with a glucoraphanin-rich broccoli-seed extract. Sixteen adults. One dose each way. Mustard-seed powder, 145 mg, moved average bioavailability from 18.6% to 39.8% (7). The trial was funded by Brassica Protection Products. Jed Fahey consulted for that company; a coauthor was employed there. The measurement is still useful. The conflict belongs in the open.
The studies, side by side
If you already eat broccoli
You do not need a sprout jar to get some of this.
Chop and wait. Chop raw broccoli and let it sit about 40 minutes before you cook it. Myrosinase needs that window. Sulforaphane, once formed, holds up to heat better than the enzyme does. Michael Greger put that step in plain kitchen language (8).
Mustard on the cooked vegetable. Frozen broccoli is usually blanched, so its own enzyme is mostly gone. A pinch of ground mustard puts myrosinase back. The 2026 trial is the measured version of that idea (7).
The inexpensive home method
This is the part we used to do, and the part I still recommend if you have the few minutes a day. Seed sold for sprouting is cheap. Greger's yield math, at the seed price he used, came out around 25 cents a cup: about 75 cups from a pound, about 2 cups from a tablespoon (9). Prices move. The method does not.
Use seed sold for sprouting, from a supplier that tests for pathogens.
Soak about a tablespoon in a wide-mouth quart jar for 6 to 8 hours. Drain.
Rinse and drain twice a day. Keep the jar tilted so water does not sit in the bottom.
Harvest at 3 to 5 days.
Rinse, dry, refrigerate, and eat within a few days.
Two jars on a stagger is enough for a household. That is the whole process. No lights required for sprouts. A sunny window is enough for microgreens if you want the cut greens instead of the jar.
We stopped because the rinse schedule kept losing to everything else on the place. That is a time problem, not a science problem.
Food safety
The same warm, wet jar that sprouts the seed also suits Salmonella, Listeria, and E. coli. The FDA tells children, pregnant women, older adults, and anyone with a weak immune system to skip raw and lightly cooked sprouts (10). Microgreens cut above the root line are a lower risk than a jar of sprouts. Home growing tells you what touched the seed. It does not make a dirty seed safe.
What we do now
If the jars are not going to happen, a supplement with the enzyme still in it is the backup. Most broccoli capsules are glucoraphanin with the myrosinase already dead. They convert at roughly the 10% rate Hopkins measured (2).
We take Avmacol Extra Strength. It is a brassica-based product — broccoli-seed and sprout glucoraphanin paired with active myrosinase, which is the part that matters. Nutramax Laboratories makes it; they are a known name in nutraceuticals and use third-party testing. That is why we trust the bottle. (Brassica Protection Products funded the 2026 mustard trial above — same plant family, different company.)
Disclosure: that is an Amazon affiliate link. As an Amazon Associate, Mindful Living Sanctuary earns from qualifying purchases, at no extra cost to you. We only link products we use.
A capsule does not replace cruciferous vegetables. If you are pregnant, on medication, or have a thyroid problem, ask your own doctor before you add one. Sprouts are the inexpensive route. The capsule is the route for people who, like us, are not going to keep the jars going.
Honest caveats
Qidong measured pollutant excretion, not cancer cases.
The autism trial was 44 young men at one site. Behavior scores, not a cure.
A lot of the other work is small or short.
Raw sprouts are a real food-safety problem for some people.
This is not medical advice. I am a veterinarian. I am not your physician.
Where we land
Cruciferous vegetables are still on our plate. The sprout jars are not. Both of those sentences can be true.
Eat broccoli, kale, cabbage, Brussels sprouts, arugula, and radish often.
Chop and wait about 40 minutes before cooking, or put ground mustard on cooked or frozen broccoli.
Grow sprouts if you can keep the rinse schedule. It is the cheap way, and the steps are above.
If you will not grow them, use a product that still has myrosinase. We use Avmacol Extra Strength.
The plate comes first. The jar or the capsule is an addition.
The original video is here: Growing a Better Tomorrow.
References
Fahey JW, Zhang Y, Talalay P. Broccoli sprouts: an exceptionally rich source of inducers of enzymes that protect against chemical carcinogens. Proceedings of the National Academy of Sciences. 1997;94(19):10367-10372. pnas.org
Fahey JW, Holtzclaw WD, Wehage SL, et al. Sulforaphane bioavailability from glucoraphanin-rich broccoli: control by active endogenous myrosinase. PLOS ONE. 2015;10(11):e0140963. journals.plos.org
Xiao Z, Lester GE, Luo Y, Wang Q. Assessment of vitamin and carotenoid concentrations of emerging food products: edible microgreens. Journal of Agricultural and Food Chemistry. 2012;60(31):7644-7651. pubmed.ncbi.nlm.nih.gov
USDA Agricultural Research Service. Specialty greens pack a nutritional punch. January 2014. ars.usda.gov
Egner PA, Chen JG, Zarth AT, et al. Rapid a
nd sustainable detoxication of airborne pollutants by broccoli sprout beverage. Cancer Prevention Research. 2014;7(8):813-823. aacrjournals.org
Singh K, Connors SL, Macklin EA, et al. Sulforaphane treatment of autism spectrum disorder (ASD). Proceedings of the National Academy of Sciences. 2014;111(43):15550-15555. pmc.ncbi.nlm.nih.gov
Mastaloudis A, Holcomb L, Fahey JW, et al. Exogenous myrosinase from mustard seed increases bioavailability of sulforaphane from a glucoraphanin-rich broccoli seed extract in a randomized clinical study. Scientific Reports. 2026;16:9162. nature.com
Greger M. Sometimes the enzyme myth is true. NutritionFacts.org. nutritionfacts.org
Greger M. Biggest nutrition bang for your buck. NutritionFacts.org. nutritionfacts.org
U.S. Food and Drug Administration. Selecting and serving produce safely. fda.gov
