1. While looking through PubMed “broccoli skin” search results, I read a 2018 study Comparative Study of Predominant Phytochemical Compounds and Proapoptotic Potential of Broccoli Sprouts and Florets that cautioned about erucic acid content in broccoli seeds:
“Our results revealed significantly higher total UFAs [unsaturated fatty acids] content in the sprouts in comparison to the florets, with very low amounts of harmful erucic [27] acid in sprouts (0.5%) and florets (2%), in comparison to the broccoli seeds (38% – data not shown).”
But its cited reference [27] Various concentrations of erucic acid in mustard oil and mustard said nothing about broccoli seeds.
Values were on a dry weight basis. Broccoli sprout age was four days.
2. Another search found this 2017 Erucic acid in feed and food position paper which stated:
“When in this Scientific Opinion the erucic acid content is reported as a percentage, this value refers to the percentage erucic acid in the total fatty acids on a weight basis.
A tolerable daily intake of 7 mg/kg body weight per day for erucic acid was established.”
See Beneficial dietary erucic acid? for important evidence available at the time that was intentionally overlooked and misinterpreted:
“Erucic acid is found to cause cardiac lipidosis in young animals, yet direct evidence of cardiac injury does not exist for young humans. Concerns about erucic acid safety and cardiotoxicity have been published in the press which are based on scientific reports in the 1970s that erucic acid disrupted oxidative phosphorylation and lead to accumulation of lipids in rat cardiac tissue.
Spanish toxic oil syndrome was a major concern, leading to questions about erucic acid cardiotoxicity. Yet it was found that not rapeseed oil per se, rather its carcinogen anilin-dye refined derivative caused cardiotoxicity.
Later, it was understood that reduced ATP production with erucic acid treatment was due to unapt isolation of rat cardiac mitochondria and lipid accumulation that was unique to rats that inherently harbour a low β-oxidative peroxisomal activity and tissue-specific metabolism of erucic acid. Similar structural or metabolic perturbations and tissue injuries were not encountered in monkeys, humans, and pigs.”
3. It referenced a 2002 Determination and Health Implication of the Erucic Acid Content of Broccoli Florets, Sprouts, and Seeds which stated:
“The erucic acid content of broccoli florets, sprouts, and seeds was found to be about 0.8, 320, and 12100 mg/100 g, respectively.”
Respective erucic acid percentages of total lipids on a fresh weight basis were provided as 0.4%, 1.1%, and 26.9%.
Florets, sprouts, and seeds had no relationships among them as they were different broccoli cultivars. Broccoli sprouts’ age wasn’t disclosed.
4. The 2002 study was updated in a 2004 Glucoraphanin and 4-Hydroxyglucobrassicin Contents in Seeds of 59 Cultivars of Broccoli, Raab, Kohlrabi, Radish, Cauliflower, Brussels Sprouts, Kale, and Cabbage which stated:
“All seed accessions contained substantial amounts of hexane-extractable lipids ranging from 21.8 to 42.0% (mean of 32.8%; 21.8-37.0 and 30.9% range and mean, respectively, for broccoli cultivars only), which were composed of 27.0-56.7% (mean of 46.7%;39.4-56.7 and 50.2% range and mean, respectively, for broccoli cultivars only) erucic acid.”
Seeds of the 2002 broccoli sprouts commercial product were measured at 31.4% lipids, with erucic acid content 51.6% of total lipids.
5. The 2018 study cited a 2013 Biochemical composition of broccoli seeds and sprouts at different stages of seedling development whose broccoli seed and sprout composition dry weights are in the below graphic:
- Broccoli seed lipid percentage of total carbohydrates plus crude fiber would be 9.36 g / (58.89 g + 15.47 g) = 12.6%.
- 3-day-old broccoli sprouts lipid percentage of total carbohydrates plus crude fiber would be 8.67 g / (54.4 g + 8.97 g) = 13.7%.
- No erucic acid contents were disclosed.
These four studies all required further work:
- 2002 couldn’t be bothered to use just one broccoli cultivar for its three measurements, or disclose broccoli sprout age.
- 2004 couldn’t resolve many of their findings with other studies.
- 2013 used weights to equate measurements, instead of relating germination stages back to a beginning number of seeds and their measurements.
- 2018 provided a bogus reference and an unsupported “broccoli seeds (38% – data not shown).” It claimed similarity with 2013, but a statistics package would say otherwise. It also didn’t comply with disclosing fatty acids weight as a percentage of broccoli sprouts weight.
Home sprouting has to deal with:
- unknown cultivar,
- unknown glucoraphanin and other glucosinolates contents,
- unknown sulforaphane and other healthy compounds, and now
- unknown erucic acid content.
Let’s reverse Microwave broccoli seeds to create sulforaphane calculations with 3-day-old broccoli sprouts have the optimal yields information to estimate an erucic acid content in one tablespoon of broccoli seeds. Measurements from Week 18 and Week 19 of Changing to a youthful phenotype with broccoli sprouts.
- Broccoli seed weight of one tablespoon 10.7 g.
- Lipids weight (10.7 g x 12.6% [2013 study]) = 1.35 g.
- Erucic acid weight in one tablespoon of broccoli seeds (1.35 g x 26.9% [2002 study]) = 0.36 g.
This 0.36 g erucic acid content would be lower than 2017 guidelines for my 70 kg weight (7 mg x 70) = 0.49 g.
Let’s reverse Estimating daily consumption of broccoli sprout compounds techniques to estimate an erucic acid content in my daily consumption of 3-day-old broccoli sprouts grown from two tablespoons of seeds:
- 131 g 3-day-old broccoli sprouts.
- Maximum lipids weight (131 g x 13.7% [2013 study]) = 17.9 g.
- Maximum erucic acid weight in 3-day-old broccoli sprouts (17.9 g x 1.1% [2002 study]) = 0.20 g.
Plug in your own numbers, but it looks like caution isn’t warranted for broccoli seed consumption. Consequences of a possible erucic acid content may be less than broccoli seeds’ healthy aspects.
One mitigation may be to start germination. Pick a point between broccoli seeds’ % of total fatty acids and ending 0.5% of 4-day-old sprouts [2018 study].
Not concerned with a daily estimate < .49 g erucic acid for broccoli seeds and sprouts. Back to a PubMed “broccoli skin” search.
See Politically correct about erucic acid and broccoli seeds for a follow up.
Surface Your Real Self 
broccoli seed has a very hight amount of Glucoraphanin which the body can use to produce sulforaphane, sulforaphane is super good for your body, yet the high-level erucic acid in broccoli seed is concerning?😣
Thanks for commenting Rui! I put a ? at the end of that to reflect the quality of the research.
I followed that up by curating a review of erucic acid that was more politics than science. I don’t keep track of EU goings on, but citing a position paper 12 times isn’t science. It’s “Shut up and obey.”
Thanks for this research! I was looking into this because Broccoli seeds appear to have significantly higher Sulforaphane content than broccoli sprouts (source below). So I was curious if the erucic acid content would be enough of a concern to avoid the seeds altogether. Good to know that the effective dose is only somewhat higher than that of sprouts, and still below the recommended upper limit. I’ll keep throwing them in as a tempering spice for my stews and curries. 🙂
Woops! Here’s the source I meant to reference:
https://www.researchgate.net/publication/268873117_Biochemical_composition_of_broccoli_seeds_and_sprouts_at_different_stages_of_seedling_development#:~:text=The%20sulforaphane%20content%20in%20seeds,high%20potential%20as%20functional%20food.
“The samples analysed showed significant differences (P≤0.05) in the sulforaphane content, and the highest value was presented in broccoli seeds (3631.91 ug/g-1of dry matter). With reference to the above, it has been reported that levels of glucosinolates in the seed are higher than in other plant tissues (Songsak & Lockwood, 2002). In the broccoli sprouts was observed a tendency of increase in the sulforaphane content with ranges of 336.32–1483.76 ug/g-1dry matter.”
It is easy to say that there is more erucic acid in seeds compared to sprouts, so avoid seeds and eat sprouts. But the same is true of the glucosinolates and both substances are largely transferred to the sprouts as they take up more water so diluting both substances to more or less the same extent. I have been using a home made broccoli seed extract containing sulforaphane to reduce oxidative stress in neurons for Parkinson’s disease and have experienced good results so far. Seeds are more practical to use than sprouts when you are seeking to find the best dose range which has been my main difficulty. Doses based on animal trials, typically in the 100 µmol range which corresponds to 2-3 g of seeds seem to be too high. By trial and error I get the best results using a much smaller dose which corresponds to a range of 0.4 to 0.6g of seeds per day. Higher doses cause some of the symptoms to get worse.
A Reddit thread for your dancing and dining pleasure: Broccoli seeds or sprouts; can someone explain this to me like I’m five?
I have been searching for this topic again after some time I have realized that eating grinded broccoli seeds with mustards create severe GI problems for me like bloating and some form of poisoning like nausea that last for many hours after consumption. Not sure what’s going on, but it’s bad enough for me to stop eating them. I have already long term GI problems (too much stomach acid, I take PPIs) so this seems to make thing a considerably worse. Not sure if that could be related to the erucic acid content in the seeds. I lowered my dose to one tea spoon instead of tablespoon however the side effects are almost as strong as before. It’s almost hard to believe that so little of something makes me feel so bad. It seems to cause some bad GI irritation for me.
Hi Andrej! Thanks for commenting.
Yes, stop if it doesn’t work for you. My issue was that there was very little science and no human studies involved.
I tried mustard seed powder per the Does sulforaphane reach the colon? human study, but 1.5 grams was too much for my stomach.
Current practice is growing one teaspoon broccoli / one teaspoon red cabbage / one teaspoon white mustard seeds (10.7 g total) together for three days, then microwaving them to 60C. That amount of mustard sprouts doesn’t bother my stomach, and they taste better together than the three sprouts separately.
Thanks for the reply!
I was growing Broccoli sprouts before, but I had two issues with it. First of all to get the everyday dose I had to have multiple jars and I had to think about it every day to water them. Even that it wasn’t all that much work overall, but it was just another thing in the list and I am usually very busy and this was a distraction.
The second reason was that growing sprouts provide very good environment for the pathological nasty bacteria to grow in them and I seems to have some issues sometimes when I eat them.
I tried to put them into vinegar and use hot water (70deg) but it seemed like way too much hassle so I started grinding the seeds which seems super convenient compared to growing sprouts but it seems like there is something about broccoli sprouts/seeds that upset my GI.
To be more accurate it’s not too bad, but it’s little bit a weird feeling and it stays for many hours pretty much the entire day and It seems like that something is not right. It’s definitely bad enough to either take smaller doses or take it with something. I don’t know. I used to mix the grinded seeds with the mustard. But I have no issues with mustard, it’s definitely the seeds.
Hi Andrej! Whatever you can do to maintain a broccoli intake would benefit you.
Subjects in the Eat broccoli sprouts every day rodent study benefited by keeping their gut microbiota engaged with hydrolyzing broccoli glucoraphanin, even when those researchers intentionally destroyed myrosinase enzyme and sulforaphane in cooked broccoli. Took them two weeks to adjust, though.
Growing sprouts takes an hour out of my day every day, since I start a new batch in the morning and evening, and rinse other batches then and midday. On Friday, I’ll start my nineteenth month of working from home every day. I couldn’t do a midday rinse on my previous work schedule.
Switched over to pint wide mouth Mason jars with plastic strainer lids a while ago. Haven’t had bacterial issues, and they speed up the routine.
I will try some smaller doses and distribute then over the day. I had some yesterday (like a quarter teaspoon) and had no issues. Will see how it goes.