A review of sulforaphane and aging

This 2019 Mexican review stated:

“We describe some of the molecular and physical characteristics of SFN, its mechanisms of action, and the effects that SFN treatment induces in order to discuss its relevance as a ‘miraculous’ drug to prevent aging and neurodegeneration. SFN has been shown to modulate several cellular pathways in order to activate diverse protective responses, which might allow avoiding cancer and neurodegeneration as well as improving cellular lifespan and health span.

NF-κB is in charge of inflammatory response regulation. Under basal conditions, NF-κB is sequestrated into the cytosol by IκB, but when pro-inflammatory ligands bind to its receptors, the IKK protein family phosphorylates IκB to degrade it via proteasome, so NF-κB is able to translocate into the nucleus and transcript several inflammatory mediators. Sulforaphane is capable to inhibit IκB phosphorylation and NF-κB nuclear translocation.

SFN upregulated Nrf2 expression by reducing DNA demethylation levels of the Nrf2 promoter. In another model using the triple-transgenic mouse model of Alzheimer’s disease (3 × Tg-AD), the use of SFN regulates the expression of the Brain-derived neurotrophic factor (BDNF) via HDAC inhibition, thus increasing H3 and H4 acetylation on the BDNF promoter. Enhancing BDNF expression as an effect of SFN treatment increased the neuronal content of several synaptic molecules like MAP 2, synaptophysin, and PSD-95 in primary cortical neurons of 3 × Tg-AD.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6885086/ “Sulforaphane – role in aging and neurodegeneration”


I came across this review while searching PubMed for sulforaphane commonalities with presentation topics in Part 2 of Reversal of aging and immunosenescent trends with sulforaphane. The review outlined some aging aspects and presented relevant sulforaphane studies. Others such as eye and muscle decline weren’t addressed.

Since sulforaphane’s “a ‘miraculous’ drug” in the Abstract, I expected but didn’t see corresponding excitement in the review body. Just phrases like “it is known” and non-specific “more research is needed.”

Other papers published after this review were found by a PubMed “sulforaphane signal aging” search:


Part 2 of Reversal of aging and immunosenescent trends with sulforaphane

Reversal of aging and immunosenescent trends with sulforaphane covered only the first 13 minutes of a super informative presentation by the lead researcher of clinical trial Reversal of aging and immunosenescent trends.  Commonalities with sulforaphane research were found by PubMed searches of sulforaphane and each presentation topic, and used a 1/1/2015 publication date cutoff.

Continuing presentation topics from the 13:40 mark:

Cancer

Lymphocyte/monocyte ratio

CD38 monocytes

  • NQO1-induced activation of AMPK contributes to cancer cell death by oxygen-glucose deprivation

    “NQO1 plays a key role in the AMPK-induced cancer cell death in OGD through the CD38/cADPR/RyR/Ca2+/CaMKII signaling pathway. The expression of NQO1 is elevated by hypoxia/reoxygenation or inflammatory stresses through nuclear accumulation of the NQO1 transcription factor, Nrf2 (NFE2-related factor 2). Activation of the cytoprotective Nrf2 antioxidant pathway by sulforaphane protects immature neurons and astrocytes from death caused by exposure to combined hypoxia and glucose deprivation.”

Thymus – no recent sulforaphane studies

Renal function

  • Rapid and Sustainable Detoxication of Airborne Pollutants by Broccoli Sprout Beverage: Results of a Randomized Clinical Trial in China

    “Rapid and sustained, statistically significant increases in the levels of excretion of the glutathione-derived conjugates of benzene (61%), acrolein (23%), but not crotonaldehyde were found in those receiving broccoli sprout beverage compared with placebo. Excretion of the benzene-derived mercapturic acid was higher in participants who were GSTT1-positive compared to the null genotype, irrespective of study arm assignment. Measures of sulforaphane metabolites in urine indicated that bioavailability did not decline over the 12-week daily dosing period. Thus, intervention with broccoli sprouts enhances the detoxication of some airborne pollutants and may provide a frugal means to attenuate their associated long-term health risks.”

Hair rejuvenation

Epigenetic clocks – There are no sulforaphane studies that use epigenetic clocks, although broccoli compounds have epigenetic effects on aging, as reviewed in 2019:

  • Sulforaphane – role in aging and neurodegeneration

    “SFN has been shown to modulate several cellular pathways in order to activate diverse protective responses, which might allow avoiding cancer and neurodegeneration as well as improving cellular lifespan and health span.”


Both biomarker (Lymphocyte / monocyte ratio) and epigenetic clock (GrimAge) measurements done 6 months after the clinical trial ended suggested trial subjects’ aging phenotypes had been reset:

An environmental signaling paradigm of aging explained:

Apart from being slowed down or sped up, the body clock can also be reset. Organisms, organs, and their cells can be reset to different age-phenotypes depending on their environment.

This is not so much a principle as an application of principle that the environment determines age-phenotype.

There wouldn’t be a potential payoff for a company to study any broccoli compound / aging connections. People can achieve clinically relevant, daily doses of broccoli sprouts for < $500 a year.

What sponsor would be interested enough to put sulforaphane research on the clock?

Presentation topics are continued in Uses of the lymphocytes to monocytes ratio and A review of sulforaphane and aging.

A pair of broccoli sprout studies

This 2015 Oregon human study found:

  • “Plasma and urinary levels of total SFN [sulforaphane] metabolites were ~3–5 times higher in sprout consumers compared to BSE [broccoli sprout extract] consumers.
  • In sprout consumers, plasma concentrations were 2.4-fold higher after consuming the second dose than after the first dose.
  • Calculated SFN bioavailability from broccoli sprouts exceeded 100%.

a Following consumption of a single 200-µmol SFN dose. b Cumulative excretion of SFN metabolites from baseline collection through the 48-hr study period. c Bioavailability F calculated based on total micromoles excreted in urine. Cmax, maximum concentration observed; AUC, area under the curve; h, hour; L, liter; t1/2, half-life; Tmax, time at Cmax. Values represent mean ± SD, n = 10.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4394840/ “Absorption and chemopreventive targets of sulforaphane in humans following consumption of broccoli sprouts or a myrosinase-treated broccoli sprout extract”


Another way to state findings:

  1. Broccoli sprouts are better than supplements.
  2. Eating sprouts twice a day is better than eating them once a day.

No explanation was given for sprout weight variability, although one was needed, because 127.6 g / 2 = 63.8 g, not 46.8 g:

“In the divided-dose phase (two weeks later), subjects (fasting) consumed half the original dose (100 μmol SFN equivalents) at 8 AM from sprouts or the BSE and the other half (not fasting) 12 h later.”

A “SFN potential” process demonstrated sulforaphane amount equivalencies, but didn’t explain non-intuitive sprout weight measurements. Was it too difficult to control sprout variability? The difficulties were instead pushed onto other researchers trying to replicate the study, and consumers looking for practical guidance.

Regardless, I adjusted my practices to twice daily start a new broccoli sprout batch with one tablespoon of seeds rather than once a day with two tablespoons. I eat them with breakfast and dinner.

I microwave 3-day-old sprouts immersed in 100 ml distilled water on full 1000W power for 35 seconds to achieve 58°C. I immediately put them into a strainer to allow further myrosinase hydrolization of glucoraphanin and other glucosinolates into sulforaphane and other healthy compounds.


I’d overlooked the above study until I saw it referenced in its successor 2018 human study Untargeted metabolomic screen reveals changes in human plasma metabolite profiles following consumption of fresh broccoli sprouts and cited it in Reversal of aging and immunosenescent trends with sulforaphane for its DHEA findings. The clinical trial treatments included:

“Both dehydroepiandrosterone (DHEA) and metformin in an attempt to limit the “diabetogenic” effect of GH [growth hormone]. DHEA has many effects, in both men and women, that oppose deleterious effects of normal aging.”

A PubMed search on DHEA found Impact of Dehydroepianrosterone (DHEA) Supplementation on Serum Levels of Insulin-Like Growth Factor 1 (IGF-1): A Dose-Response Meta-Analysis of Randomized Controlled Trials which confirmed the clinical trial’s DHEA dose would increase IGF-1.

This study observed a significant decrease in DHEA after eating broccoli sprouts, but didn’t provide a plausible explanation for this finding, or cite relevant studies. Ten other significant decreases were related to antioxidants and fatty acids.

It isn’t clear that I needed to take DHEA anyway, since the clinical trial’s purpose for DHEA treatment was to oppose effects of growth hormone, which I’m not taking. But I’m getting good results, so I’ll just keep doing what I’ve been doing for a limited time.

The study said:

“While this study focuses largely on the potential effects of SFN, broccoli sprouts contain many other bioactive components that could be responsible for our observations as well as additional health benefits.”

Our model clinical trial Effects of long-term consumption of broccoli sprouts on inflammatory markers in overweight subjects said much the same:

“The anti-inflammatory effects observed with broccoli sprouts intake are likely due to the combined effects of all the hydrolysis products of glucosinolates.”

The 3-day-old broccoli sprouts have the optimal yields study said:

Although germination reduces SF [sulforaphane] yield to some extent, it is beneficial to the formation and accumulation of total phenol and flavonoids, ensuring the health properties of sprouts.”

Combining the pair of Oregon studies’ findings:

  1. Broccoli sprouts are better than supplements.
  2. Eating sprouts twice a day is better than eating them once a day.
  3. When in doubt, refer back to Item 1.

 

Reversal of aging and immunosenescent trends with sulforaphane

Sulforaphane research findings have commonalities with a super informative presentation by the lead researcher of clinical trial Reversal of aging and immunosenescent trends. I did a PubMed search of sulforaphane and each presentation topic, and used a 1/1/2015 publication date cutoff.

Presentation topics through the first 13 minutes were:

Thymus – no recent sulforaphane studies

Treatments

PSA

C-reactive protein and IL-6

Bone marrow fat – no recent studies

T cells

PD-1 / PD-L1

Treatment cost

I estimate the annual cost of the non-prescription treatments of the clinical trial to be $100. The estimated annual cost of eating broccoli sprouts every day is < $500 for the broccoli seeds.

broccoli seed label

The above image isn’t an endorsement although it’s what I’ve used. It’s buzzword marketing to put “sprouts” and “sulforaphane” but not “seeds” on the label of a broccoli seeds package. For another thing, broccoli sprouts don’t “abound with phytochemical sulforaphane.”

Repeating a point from Estimating daily consumption of broccoli sprout compounds, broccoli seeds and sprouts contain little or no sulforaphane. They have glucoraphanin and myrosinase enzyme which are structurally separated. Disturbing their cells mixes the two, and the enzyme hydrolyzes glucoraphanin and other glucosinolates into sulforaphane and other healthy compounds.

Continue presentation topic commonalities with sulforaphane research at A pair of broccoli sprout studies and Part 2 of Reversal of aging and immunosenescent trends with sulforaphane.

Reevaluate findings in another paradigm

It’s challenging for people to change their framework when their paychecks or mental state or reputations depend on it not changing.

I’ll use The hypothalamus and aging as an example. The review was alright for partial fact-finding up through 2018. The review’s facts were limited, however, to what fit into the reviewers’ paradigm.

The 2015 An environmental signaling paradigm of aging provided examples of findings that weren’t considered in the review. It also presented a framework that better incorporated what was known at the time.


Here’s how they viewed the same 2013 study, Hypothalamic programming of systemic ageing involving IKK-β, NF-κB and GnRH (not freely available).

Paradigm: “The hypothalamus is hypothesized to be a primary regulator of the process of aging of the entire body.”

Study assessment:

“The age-associated inflammation increase is mediated by IκB kinase-β (IKK-β) and nuclear factor κB (NF-κB) in the microglia and, subsequently, nearby neurons through the microglia–neuron interaction in the mediobasal hypothalamus. Apparently, blocking the hypothalamic or brain IKK-β or NF-κB activation causes delayed aging phenotype and improved lifespan.

Aging correlates with a decline in the hypothalamic GnRH expression in mice and, mechanistically, activated IKK-β and NF-κB significantly down regulates the GnRH transcription. Notably, GnRH therapy through either hypothalamic third ventricularor subcutaneous injection leads to a significant recovery of neurogenesis in the hypothalamus and hippocampus and a noticeable improvement of age-related phenotype in the skin thickness, bone density, and muscle strength when applied in middle-aged mice.”

Paradigm: Environmental signaling model of aging

Study assessment:

“A link between inflammation and aging is the finding that inflammatory and stress responses activate NF-κB in the hypothalamus and induce a signaling pathway that reduces production of gonadotropin-releasing hormone (GnRH) by neurons. GnRH decline contributes to aging-related changes such as bone fragility, muscle weakness, skin atrophy, and reduced neurogenesis. Consistent with this, GnRH treatment prevents aging-impaired neurogenesis and decelerates aging in mice.

Zhang et al. report that there is an age-associated activation of NF-κB and IKK-β. Loss of sirtuins may contribute both to inflammation and other aspects of aging, but this explanation, also given by Zhang et al. merely moves the question to why there a loss of sirtuins.

The case is particularly interesting when we realize that the aging phenotype can only be maintained by the continuous activation of NF-κB – a product of which is the production of TNF-α. Reciprocally when TNF-α is secreted into the inter-cellular milieu, it causes the activation of NF-κB. In their study, Zhang et al. noted that the activation of NF-κB began in the microglia (the immune system component cells found in the brain), which secreted TNF-α, resulting in a positive feedback loop that eventually encompassed the entire central hypothalamus.

The net result of this is a diminution in the production of gonadotropin-releasing factor which accounted for a shorter lifespan because provision of GnRH eliminated that effect, while either preventing NF-κB activation (or that of the IKK-β upstream activator) or by providing gonadotropin-releasing factor directly into the brain, or peripherally, extended lifespan by about 20%.

In spite of the claim of Zhang et al. that the hypothalamus is the regulator of lifespan in mice, their experiments show that only some aspects of lifespan are controlled by the hypothalamus, as preventing NF-κB activation in this organ did not stop aging and death. Similar increased NF-κB activation with age has been seen in other tissues as well and said to account for dysfunction in aging adrenal glands. It was demonstrated that increased aging occurred as a result of lack of gonadotropin-releasing hormone and that increased lifespan resulted from its provision during aging.

In this manner:

  1. The aging of hypothalamic microglia leads to
  2. The aging of the hypothalamus, which leads to
  3. Aging elsewhere in the body.

So here we have a multi-level interaction:

  1. The activation of NF-κB leads to
  2. Cellular aging, leading to
  3. A diminished production of GnRH, which then
  4. Acts (through the cells with a receptor for it, or indirectly as a result of changes to GnRH-receptor-possessing cells) to decrease lifespan.

So the age state of hypothalamic cells, at least with respect to NF-κB activation, is communicated to other cells via the reduced output of GnRH.”


Not using the same frameworks, are they?

In 2015, the researcher told the world what could be done to dramatically change the entire research area. He and other researchers did so recently as curated in Part 3 of Rejuvenation therapy and sulforaphane which addressed hypothalamus rejuvenation.

A hair color anecdote

Will you excuse a poorly-evidenced observation that’s a positive development I left out of Week 8 of Changing to a youthful phenotype with broccoli sprouts?

I got a haircut last weekend after waiting for Governor Klan Robes Blackface to not arrest barbershop and hair salon owners for the crime of earning a living. A thirty-something tattooed barber wearing a face mask and face shield said my last haircut had been on February 1, 2020, so it had been 14 weeks. She used a #4 clipper to cut everything to about 1/2 inch.

I’d eaten broccoli sprouts every day for 7 weeks at that point. Post-haircut visible hair was all from that period, probably since Week 3, which was also when broccoli sprouts’ effects on inflammation became noticeable.

One evening as I brushed my teeth, I noticed overall hair appearance was mainly dark brown again, an unexpected phenomenon. Maybe white hair will show up as it gets longer?

Feedback on hair color from a back-of-the-head picture was mixed, ranging from “Yes. Definitely!” to Unsupported non-evidence since before and after pictures weren’t taken under the same lighting conditions. Even if validated, other factors could be in play, such as working from home without the stress of going into work.


While eating my usual steel cut oats for breakfast this morning, I remembered a super informative presentation by the lead researcher of clinical trial Reversal of aging and immunosenescent trends. I rewatched it, pausing after two minutes to reabsorb when he said:

“There’s a collapse that takes place somewhere between the ages of sixty to eighty in which you lose 98% of your ability to recognize foreign antigens.”

You will have forgotten why I drew your attention to this super interesting presentation by the 21:25 mark. But pause for the “Hair Rejuvenation?” slide with before and after photos:

“A couple of guys came to us and said they seemed to notice that their hair was growing in darker again. It’s an anecdote. It didn’t apply to most of the guys. But it’s a sign that maybe something interesting is going on.”

That’s followed by epigenetic clock findings using four different clocks. Note that no significant effects on biological age were found until the trial’s 9-month point, and those weren’t as strong as improvements by 12 months.

Improvements accelerated between 9 and 12 months, and at 12 months, subjects had increased their life expectancies by 2 years. The GrimAge clock showed the subjects’ predicted lifespan and health span was unchanged 6 months after the trial ended.


I started and have continued four lifestyle “interventions” since last summer:

  1. In July I dramatically reduced my consumption of advanced glycation end products after reading Dr. Vlassara’s AGE-Less Diet: How a Chemical in the Foods We Eat Promotes Disease, Obesity, and Aging and the Steps We Can Take to Stop It.
  2. In September I started this trial’s non-prescription daily treatments of Vitamin D, zinc, and DHEA.
  3. Also in September, I started non-prescription intermittent quercetin treatments of Preliminary findings from a senolytics clinical trial.
  4. Eight weeks ago I started eating broccoli sprouts every day per clinical trial Effects of long-term consumption of broccoli sprouts on inflammatory markers in overweight subjects.

In a month or so I should be able to say whether or not my hair really is growing in darker. One way to find out which “intervention” had the largest effect may be to stop one or more of them. That might happen anyway because:

  1. Consistently eating AGE-less food is boring.
  2. I’m leery of taking more than RDAs.
  3. Ehh.
  4. I still sadly hope against reality that we’re past the Madness of Crowds phase and can accelerate the “recover their senses slowly, one by one” phase. It would be harder to take care of my broccoli sprout farm if I have to go into work every day.

Or maybe An environmental signaling paradigm of aging is correct, and at a certain point, clocks are reset and none of these “interventions” will be needed? What do you think?

 

Week 8 of Changing to a youthful phenotype with broccoli sprouts

To follow up Week 7 of Changing to a youthful phenotype with broccoli sprouts:

1. I changed practices per Enhancing sulforaphane content. After microwaving to achieve 60°C, I now transfer broccoli sprouts to a strainer, and allow further myrosinase hydrolization of glucoraphanin and other glucosinolates into sulforaphane and other healthy compounds. I previously cooled them immediately.

They taste better, too, and I stopped putting mustard in them to make them more palatable. What does letting 3-day-old broccoli sprouts cool down by themselves to increase sulforaphane do that makes them more agreeable?

Despite improving yields two weeks ago, 3-day-old broccoli sprouts started from two tablespoons of broccoli seeds still fit into a Corning Ware 16 fl. oz. / 473 ml container:

2. I made worst-case estimates in Estimating daily consumption of broccoli sprout compounds of 21 mg sulforaphane without microwaving and 30 mg sulforaphane with microwaving in 3-day-old broccoli sprouts. They fit within:

“The daily SFN [sulforaphane] dose found to achieve beneficial outcomes in most of the available clinical trials is around 20-40 mg.”

The post’s point was: how can a person guide their actions with evidence when a broccoli cultivated variety’s beneficial characteristics aren’t known? I’ll repeat a sulforaphane yields graphic from the 3-day-old broccoli sprouts have the optimal yields study for examples of unknowns:

A. If sulforaphane content was a consumer’s overriding concern. the above evidence suggests that it would be better to always eat the seeds of an unknown cultivar. A tablespoon seems like a good choice, but be sure to chew the broccoli seeds thoroughly (try for five minutes) to release myrosinase and glucoraphanin.

The first minute goes alright. Sometime after that, your mouth and the back of your throat starts to burn. That will be a reminder of an evolved function that protects plants from predators.

I haven’t successfully swallowed a mouthful of thoroughly chewed broccoli seeds without also eating something else or drinking more than just water. That might not go along with your plan for a snack or eating before bedtime.

B. The study recommended consuming 3-day-old sprouts because:

Although germination reduces SF [sulforaphane] yield to some extent, it is beneficial to the formation and accumulation of total phenol and flavonoids, ensuring the health properties of sprouts.”

Fine, but if your unknown cultivar’s sulforaphane characteristics look like the third cultivar’s 3-day-old sprouts, you’ll have a 53% reduction in the sulforaphane weight. Should you take a 1-in-6 chance with Day 5 sprouts? Or stick with Day 3, guessing that they may still yield more sulforaphane than 3 of the 5 other cultivars’ Day 3 broccoli sprouts?

C. What if you can’t stomach the appearance of 3-day-old broccoli sprouts per the above photo, and you prefer microgreens? Should you wait until Day 7, and take a 1-in-6 chance that your unknown cultivar’s characteristics are like the highest Day 7 of the fourth cultivar? When you roll the die, does it come up 4?

Broccoli seed bulk suppliers aren’t providing evidence for their products and educating customers. Their marketing strategy depends more on buzzwords and price.

3. I compared lab reports of 3 broccoli sprouts’ cultivars in Lab analyses of broccoli sprout compounds to see if they helped rationally deal with these unknowns. It turned out that not much could be accurately inferred from lab reports, past knowing that broccoli sprouts of one cultivar produced more sulforaphane than another.

I haven’t found studies of cultivar characteristics for items I could actually purchase in bulk. I contacted five small US and Canadian suppliers to ask “Do you sell broccoli seeds that have lab evidence of the cultivar’s sulforaphane content?” Two said no so far. I contacted another supplier for the home garden business who has two dozen cultivars listed for sale and asked them the same question.

None of the broccoli seed bulk suppliers specified the cultivar on their offering. When pressed on Amazon they at best said Calabrese, which has described hundreds of cultivars. Such as two in this study, Iron Man and Marathon, which are also named Calabrese Iron Man F1 and Calabrese Marathon F1.

4. I’ve had only sporadic inflammation, and I’m tempted to write anecdotes of positive things. But self-reports are better evidence for emotions than for other internal events.

See Week 9 of Changing to a youthful phenotype with broccoli sprouts for follow ups.

Enhancing sulforaphane content

This 2020 Chinese study experimented with enhancing sulforaphane content of broccoli florets in a range of conditions:

“For direct water blanching at 60°C, the sulforaphane yield increased with treatment time from 1698.0 ± 121.9 μmol per kg DW (0 min) to 2833.3 ± 118.6 μmol per kg DW (1 min) and then steadily decreased to the lowest value of 2345.8 ± 57.7 μmol per kg DW for 5 min.”

The sulforaphane yield was 503.7 ± 23.8 μmol per kg DW of broccoli after 5 min thermal treatment at 65 °C, which was even lower than the value obtained for raw broccoli. The reason could be the leaching of glucoraphanin into the blanching water coupled with partial inactivation of myrosinase resulting in low yield of sulforaphane.

For direct water blanching, the best treatment temperature for maximizing sulforaphane yield was 60 °C, which is similar to the best treatment temperature for maximizing sulforaphane yield reported previously.

Sulforaphane yield depends on the relative activity of myrosinase and ESP in the broccoli matrix and 3 min treatment at 65 °C during in-pack processing in this study was found to be the best condition that favours conversion into sulforaphane instead of sulforaphane nitrile. This indicates that the condition favours the inactivation of ESP to a larger extent while maintaining sufficient myrosinase activity resulting in optimal conversion into sulforaphane.

Under this condition, it seems that all of the extractable glucoraphanin is converted to sulforaphane assuming 1 to 1 conversion, since the glucoraphanin content of the broccoli samples were determined to be 3141.2 μmol per kg DW whereas the sulforaphane yield was 3983 μmol per kg DW. The slightly higher sulforaphane yield than would be predicted from the level of glucoraphanin in raw broccoli requires further investigation.”

https://pubs.rsc.org/en/content/articlehtml/2020/fo/c9fo02089f “Mild heat combined with lactic acid fermentation: a novel approach for enhancing sulforaphane yield in broccoli puree”


1. The study presented evidence for kitchen practices:

  • Per the above graphic’s point a, I’ve changed to let broccoli sprout heating continue for 1 minute after microwaving to achieve 60°C. This allows further myrosinase hydrolization of glucoraphanin into sulforaphane. My practice had been to immediately cool them down, which was suboptimal point c on the 60°C line. I still transfer the broccoli sprouts to a strainer immediately after microwaving.
  • The 60°C (140°F) cliff finding of Microwave broccoli to increase sulforaphane levels was confirmed.

2. I didn’t view this study’s in-pack or lactic acid bacteria fermentation findings as having practical kitchen use. Maybe it’s a cultural difference?

3. Poor performance at 65°C after 5 minutes was partially attributed to “leaching of glucoraphanin into the blanching water.” But poor 65°C performance was evident at the 1 minute point compared with good 60°C performance.

“Partial inactivation of myrosinase” at 65°C was more likely to be the dominant factor.

4. Regarding:

“The slightly higher sulforaphane yield than would be predicted from the level of glucoraphanin in raw broccoli requires further investigation.”

The microwaving study author was on a productive investigation track with:

“Microwave irradiation might help to release more conjugated forms of glucosinolates and then get hydrolyzed by released myrosinase.”

That track developed in part from finding that broccoli florets microwaved on full power to 60°C increased glucoraphanin past control (raw) levels:

“The control GLR amount was 2.18 µmol/g DW, while the HL60 GLR amount was 2.78 µmol/g DW.”

Not to mention the coincident 1,114% increase in sulforaphane content of ordinary broccoli purchased at a grocery store!


I arrived at this study through it being referenced in the enjoyable 2020 Spanish review Functional Ingredients From Brassicaceae Species: Overview and Perspectives. The reviewers noted that this study’s 2019 predecessor Fermentation for enhancing the bioconversion of glucoraphanin into sulforaphane and improve the functional attributes of broccoli puree (not freely available) found:

“Preferential formation of SFN-nitrile (less potential as inducer of phase II detoxification enzymes than SFN) instead of SFN.”

Estimating daily consumption of broccoli sprout compounds

Strikethroughs are mainly from Week 18 of Changing to a youthful phenotype with broccoli sprouts measurements.

Rainy day thought for the 13th week of lockdown: What are methods of estimating the minimum contents of broccoli sprouts for those of us who aren’t willing to turn their kitchen into a laboratory?

With the 3-day-old broccoli sprouts have the optimal yields study as a reference, minimum values of the six broccoli cultivated varieties studied were:

  1. Lowest weight of 100 seeds: .33 grams.
  2. 100 of that cultivar’s 3-day-old sprouts weighed 1.55 grams.
  3. A different cultivar had the lowest total phenolics (gallic acid equivalents): 0.94 mg per gram of 3-day-old sprouts.
  4. That second cultivar also had the lowest total flavonoids (rutin equivalents): 1.02 mg per gram of 3-day-old sprouts.
  5. A third cultivar had the lowest weight of sulforaphane in its seeds: 2.43 mg per gram of seeds.
  6. Reduction of sulforaphane content during germination from seeds to 3-day-old sprouts is evident from the below chart. The only 3-day-old sprout chart number the study provided was the best case, though. I requested the study data, but in the meantime..I enlarged the chart, measured the worst cultivar as a 8.5 cm bar where the seed bar was 16 cm. Its 3-day-old sprout sulforaphane yield was ~53% of its seed yield.

sprout ages 1B

Another caveat for contents: Researchers had to process broccoli seeds and 3-day-old broccoli sprouts in order to make measurements. Total phenolics and total flavonoids may not have been affected by processing. However, processing generated sulforaphane.

Broccoli seeds and 3-day-old broccoli sprouts contain little or no sulforaphane. They have glucoraphanin and myrosinase enzyme which are structurally separated. Disturbing their cells mixes the two, and the enzyme hydrolyzes glucoraphanin and other glucosinolates into sulforaphane and other healthy compounds.


I start out each daily batch with two tablespoons of broccoli seeds of an unknown cultivar. I counted 812 broccoli seeds in a teaspoon (yes, I did), and multiplied by 6 for 4,872 total seeds.

Runt-of-the-litter calculations for the six broccoli cultivars studied are:

  • (4,872 / 100) x .33 g = 16.08 10.7 g x 2 = 21.4 g broccoli seeds;
  • (4,872 / 100) x 1.55 g = 75.52 48.0 x 2 = 96.0 g 3-day-old broccoli sprouts;
  • 75.52 96.0 g x 0.94 mg per gram of 3-day-old sprouts = 70.99 90.2 mg total phenolics;
  • 75.52 96.0 g x 1.02 mg per gram of 3-day-old sprouts = 77.03 97.9 mg total flavonoids;
  • 16.08 21.4 g broccoli seeds x 2.43 mg per gram of seeds = 39.07 52.0 mg sulforaphane;
  • 39.07 52.0 mg x 53% = 20.71 27.6 mg sulforaphane in 3-day-old broccoli sprouts without microwaving them.

I’ll use the Microwave broccoli to increase sulforaphane levels study as a reference for an alternate sulforaphane calculation. The cultivar wasn’t mentioned, only that it was ordinary broccoli purchased in Silver Spring, Maryland, grocery stores.

One assumption is that microwaving broccoli sprouts will have the same effects as microwaving broccoli florets to increase sulforaphane content. Are the similarities between broccoli floret and broccoli sprout characteristics enough to say whether or not that’s a valid assumption?

Another assumption is that there’s no beginning amount of sulforaphane in 3-day-old broccoli sprouts. Microwaving them on full power to 60°C produces all of the sulforaphane.

A third assumption is that the sulforaphane increase from .22 to 2.45 µmol / g of the tested broccoli florets fairly represents other broccoli florets.

Combining this with the worst-case calculated weight of 3-day-old broccoli sprouts in the first study:

((2.45 – .22 µmol / g)

x 75.52 96.0 g 3-day-old broccoli sprouts)

/ 5.64 μmol conversion of amount to weight

= 29.86 38.0 mg sulforaphane


Sulforaphane: Its “Coming of Age” as a Clinically Relevant Nutraceutical in the Prevention and Treatment of Chronic Disease concluded:

“The daily SFN [sulforaphane] dose found to achieve beneficial outcomes in most of the available clinical trials is around 20-40 mg.”

I’ll guess that my daily consumption of broccoli sprout compounds is at least in this clinical trial range with worst-case calculations of 20.71 27.6 ≈ 21 28 mg sulforaphane without microwaving and 29.8630 38 mg sulforaphane with microwaving in 3-day-old broccoli sprouts. I’ll include this estimate in Week 8 of Changing to a youthful phenotype with broccoli sprouts.

Microwave broccoli to increase flavonoid levels demonstrated 108.5% to 129.8% increases in quercetin and kaempferol levels from microwaving ordinary broccoli purchased in a Beltsville, Maryland, grocery store. I won’t use their method of a 1200W microwave on full power for one minute, but microwaving may be expected to increase the worst-case calculation of 77.03 97.9 ≈ 77 98 mg total flavonoids.

Broccoli seed suppliers are missing a marketing opportunity by not specifying their cultivars. They could be advertising specific benefits, etc.

The first study showed that sulforaphane contents vary widely among broccoli cultivars, from the 2.43 mg used above to 12.07 mg per gram of seeds. If your product was almost 5 times better than a competitor’s, why wouldn’t you advertise it?

Week 7 of Changing to a youthful phenotype with broccoli sprouts

To follow up Week 6 of Changing an inflammatory phenotype with broccoli sprouts:

1. I changed the title of this week’s update as a result of reading the study in A rejuvenation therapy and sulforaphane. The study wasn’t about sulforaphane, but its clinical findings had commonalities with this broccoli sprouts effort. It’s become the blog’s most popular post, read by people in 50+ countries.

A close second is An environmental signaling paradigm of aging. The study’s lead laboratory researcher presented his view five years ago on where aging evidence was pointing.

Part 2 of Rejuvenation therapy and sulforaphane better curated the study’s innovative epigenetic clock results. There are no sulforaphane clinical trials that also use epigenetic clocks.

What are the effects that broccoli sprouts and their compounds may have on human aging? With this new human-rat relative biological age clock, researchers can get reliable answers from rat studies, with human clinical trials needed only to confirm those findings!

2. This week I found out that exercising control over my charges to protect them from disease was counterproductive. I exposed them to harm, destroyed their community, and stunted their growth by forcing them to distance from each other for their own good.

Am I a politician, an unelected bureaucrat, or some other form of busybody? No. I admit my mistakes right away, I apologize, then I immediately try to do better.

A proper context:

  • In Week 2 I switched from sprouting trays with 1/16″ high ridges in the bottom to Russian-doll bowls. That solved a problem of excess moisture, with which broccoli sprouts don’t do well but bacteria do.
  • In Week 3 I rotated in the next larger sized bowl to replace the smallest bowl. My thought was that Day 3 broccoli sprouts were too crowded to dry in the smallest bowl.
  • At the end of Week 5 I doubled the starting amount of broccoli seeds from one to two tablespoons. To accommodate that increase, I again rotated in the next larger size bowl to replace the smallest bowl.

Starting in Week 6, I had uneven batch yields. The two larger bowls yielded noticeably fewer sprouts than did batches in the two smaller bowls.

What did bowl size have to do with yield? Nothing, it was me. It turned out I’d neglected Plant Care 101 instructions to provide adequate moisture.

After rinsing, straining, and wicking out excess moisture with a paper towel twice daily, I then spread out the seeds and sprouts to prevent problems with excess moisture. The broccoli seeds and sprouts in the two larger bowls were more separated than in the two smaller bowls.

All of which led to moisture levels that were inadequate for broccoli seeds and sprouts. All batches sprouted less well than their potential yield. The larger the bowl, the more my behavior adversely affected the batch.

Here’s what Day 2 and Day 3 yields were with my previous practices.  The batch volume of Day 2 in the smaller bowl was larger than Day 3’s:

I changed practices to group broccoli seeds and sprouts together at the step where I used to spread them out. Here’s the same bowl with my current practice, but at Day 2. The photo may not show it well, but it’s a larger volume than the previous practice’s Day 2:

I’ll guess that batch yield volumes have improved by 60% 75%. I increased distilled water from 100 ml to 160 175 ml before microwaving since 100 ml no longer completely immersed the increased Day 3 broccoli sprout volume. My 1000W full power microwave time concomitantly increased from 45 seconds to 70 65 seconds to achieve 58°C.

The better-developed batches also taste better. I still mix in mustard and eat Day 3 broccoli sprouts with other food.

3. My sulforaphane intake has probably decreased with the current practice. The 3-day-old broccoli sprouts have the optimal yields study said:

Although germination reduces SF [sulforaphane] yield to some extent, it is beneficial to the formation and accumulation of total phenol and flavonoids, ensuring the health properties of sprouts. SF contents in sprouts were 46% – 97% of seeds, whereas TP [total phenolic] and TF [total flavonoid] contents in sprouts were 1.12 – 3.58 times higher than seeds among [broccoli] varieties.”

I’m not concerned about less sulforaphane with a two tablespoons starting amount of broccoli seeds. Even a one tablespoon starting amount yields 60 g of broccoli sprouts, twice that of the model clinical trial, Effects of long-term consumption of broccoli sprouts on inflammatory markers in overweight subjects. See our discussion in Understanding a clinical trial’s broccoli sprout amount.

4. Another week of no inflammatory problems after four-to-six-mile-long beach walks. I’m not pushing myself, just walking often, and working out my upper body every fourth day.

I emphasize the eccentric motion in upper body workouts. I haven’t curated the below 2019 papers although they’re informative:

I don’t expect recovery times from workouts to shorten. What’s an appropriate exercise recovery time? found with 26.5 ± 6.5 year-old male subjects that even three days wasn’t enough time for the biceps brachii to fully recover from eccentric exercise.

5. During Friday’s walk I accidentally startled a large turkey hen who was on the ground, and she flew up on a fence. Can you see her moments before she hopped down to the other side?

Don’t have any idea what bugs a turkey found attractive near a beach.

See Week 8 of Changing to a youthful phenotype with broccoli sprouts for follow ups.