Sulforaphane is found naturally in broccoli and sprout extracts. Broccoli sprout extracts with sulforaphane are popular nutritional supplements used for detoxification. This article will go over the results of some studies using broccoli extracts with sulforaphane.
One Sulforaphane study showed support for stem cells, which could be relevant for anti-aging and tissue repair. Another Sulforaphane study showed improved detoxification and elimination of air pollution chemicals. This article does not cover the antibacterial or anticancer activities as these are more preliminary. For example, right now a Phase 2 trial of sulforaphane as add-on treatment for prostate cancer is ongoing.
FYI: Clicking on links will go to research articles in a new tab
In a nutshell: getting sulforaphane from broccoli
- Even refrigerated broccoli loses up to 80% of its sulforaphane
- Sulforaphane from raw broccoli is 11 times more bioavailable
- Sulforaphane levels in broccoli change widely
Yes, mom was right - eating vegetables is important. I'd love to say that eating broccoli will give you good amounts of sulforaphane... Unfortunately sulforaphane levels are all over the place in broccoli and change with each crop. Even worse, sulforaphane and its mother chemical glucoraphanin break down after broccoli is harvested - even if the broccoli is refrigerated. And for you cooked veggie lovers: this 2008 journal study showed that cooking broccoli will decrease your absorption of sulforaphane.
Apparently you have to live on a farm and have forgotten the recipe for boiling water in order to get reliable Sulforaphane amounts from food.
I believe in the "Oxidant Theory of Aging", also known as the "Free Radical Theory of Aging". This theory considers the repetitive injury caused by free radicals (electrons) to our DNA to be a strong factor in the aging process. Do I think oxidation is the only cause of aging? Of course not, but it may be a factor you can influence. You cannot escape free radicals – they're always around, and even necessary for important functions, but finding ways to stop excessive oxidation may help extend cell life.
Why I care: Sulforaphane was found in this UCLA clinical trial to increase Phase II antioxidants in the upper airway of humans.
Sulforaphane supports stem cells
In a nutshell: the right dose of sulforaphane helps stem cells grow
- 3 days of Sulforaphane increased growth of stem cells
- Too much Sulforaphane increased stem cell death
This study, published in AGE in 2012, showed that certain doses of Sulforaphane can increase the growth and decrease the death of Mesenchymal Stem Cells. These stem cells are made in bone marrow and travel through your body, with the ability to repair tissues by transforming into other cell types.
The researchers examined the effect of Sulforaphane on these stem cells directly, showing increased growth at a low dose, and increased cell death at too high of a dose.
Later I discuss how dosing relates to blood levels and what doses were used for different studies.
It's a dirty, dirty world and some places are worse than others. One of the nastier regions for air pollution is Qidong, China. The infamous “Asian Brown Cloud” hangs over this region, a powerful symbol of air contamination.
This area of China is so well known for pollution that John's Hopkins University teamed up with the Masonic Cancer Center of Minnesota and the Qidong Liver Cancer Institute to find ways to help people detoxify air pollution better. They tested if broccoli sprout extracts with sulforaphane would help people eliminate this airborne pollution.
The results, published in 2012 in Carcinogenesis, showed that:
- Sulforaphane increases urine excretion of pollution by 50%
- Sulforaphane activates enzymes that modify pollutants to excrete them faster
When people were taking Glucoraphanin or Sulforaphane, they urinated out between 20% and 50% more pollution chemicals - ones like Crotonaldehyde, Acrolein, and Benzene. The researchers believe Sulforaphane activates enzymes called Glutathione-S-transferases, which then modify toxic compounds so that they can be excreted.
Broccoli extract with Sulforaphane might actually be useful for a variety of reasons. The trick is getting the proper dose. Food sources are unreliable, so obtaining sulforaphane by standardized extracts is a more efficent way for me, and using a quality laboratory tested brand is essential to get the dosing range I want.
Sulforaphane dosing in a nutshell
- 25mg dose of Sulforaphane daily is roughly the detoxification study level
- 75mg of Sulforaphane is maximum amount that benefited stem cells
- 300mg of Sulforaphane was found to be toxic to stem cells
- according to studies Sulforaphane is eliminated fast, without buildup
I personally use Crucera SGS - this is a broccoli extract standardized for Sulforaphane - each capsule provides 25mg Sulforaphane and it is reasonably priced when using 1 capsule a day.
** Main article ends here - down below are calculations & Sulforaphane dosing discussion
Dosages and effects seen in the discussed studies:
0.25uM, 1uM, 5uM [concentrations]
Better cell growth & survival
More cell death
150uM – daily intake
More pollutants urinated out
Note the distinction between Sulforaphane doses used – concentration in the Sulforaphane stem cell study is absolutely not the same thing as the daily intake in the Sulforaphane detoxification study.
- Sulforaphane stem cell study was in test tube; the doses are measured as the level of chemical in fluid around the cells.
- Sulforaphane pollution detoxification was a human study; they reported the total amount of Sulforaphane subjects had daily.
Dose of Sulforaphane in Pollution study
Dose of Sulforaphane in Stem Cell study* (see bottom for calculations)
Bioavailability and Kinetics of Sulforaphane in Humans after Consumption of Cooked versus Raw Broccoli
Vermeulen et al. Journal of Agricultural and Food Chemistry. 2008, 56, 10505-10509
Dose-dependent effects of R-sulforaphane isothiocyanate on the biology of human mesenchymal stem cells…[variable dosage effects]
Zanichelli et al. AGE (2012) 34:281-293
Modulation of the metabolism of airborne pollutants by Glucoraphanin-rich and Sulforaphane-rich broccoli sprout beverages in Quidong, China
Kensler et al. Carcinogenesis vol.33 no.1 pp101-107, 2012
Repeated intake of broccoli does not lead to higher plasma levels of Sulforaphane in human volunteers
Hanlon et al. Cancer Letters 284 (2009) 15-20
How did I translate Sulforaphane level in the Stem Cell study to an oral supplement?
Many studies use a Glucoraphanin source and then have it convert to Sulforaphane. You have to extrapolate and cross your fingers. I decided to use the “raw” data from the Raw VS Cooked Broccoli Sulforaphane bioavailability study:
9.92uM/serving X 177.29 = 1.76mg Sulforaphane per raw serving in study
Average peak blood level of Sulforaphane from the raw serving: 103nM = 0.1uM
So – 1.76mg of raw Sulforaphane gave 0.1uM level in the blood.
Sulforaphane Stem cell study:
0.25uM - 5uM level promoted growth and inhibited death - equivalent to 88mg Sulforaphane
20uM level promoted stem cell death - equivalent to 352mg SulforaphaneAuthor: Dr David Woznica, M.D.
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