A number of foods have known anti-cancer activity. Among the more well-known are members of the cruciferous family, with broccoli leading the pack when it comes to undergoing scientific investigation. One of the lesser-known ones is mustard seed, which also belongs to the brassica genus.^1,2

As it turns out, not only does mustard seed contain compounds shown to inhibit cancer proliferation, it also contains compounds that augment the cancer-fighting potential of other cruciferous veggies, delivering a real double-punch when combined. For this reason, I recommend keeping organic mustard seed powder in your kitchen at all times. Mustard seed powder can also be used to whip up homemade topical remedies, such as plasters and baths to relieve pain.

Mustard Seed Compound Effectively Blocks Bladder Cancer Progression

One 2010 study³ discovered a compound found in both brown mustard and cruciferous vegetables called allyl isothiocyanate (AITC), also known as mustard oil, lowered the risk of bladder cancer by 34.5 percent and was 100 percent effective at preventing the spread of cancer into surrounding muscle cells. The complete stop of cancer progression is quite remarkable considering the cancer metastasized into surrounding tissues 71 percent of the time in untreated controls.

Importantly, the whole food — mustard seed powder — was more effective than the purified form. Dry mustard seed contain a compound called sinigrin, a precursor to AITC. When combined with water (which is what happens in your stomach), an enzyme called myrosinase converts the sinigrin into AITC.

A related form of this enzyme is found in the human digestive tract, but the plant-based one is far more effective, accomplishing a more complete conversion. This is likely why the whole food worked better than the isolated compound.⁴ Another interesting finding was that higher doses were not more effective. Animals given 71.5 milligrams (mg) of mustard seed powder per kilo of body weight were the ones in which cancer occurrence was reduced by 34 percent and metastasis completely blocked.

In animals treated with 715 mg of mustard seed powder per kilo, tumor growth was reduced by just 23 percent, and tumor invasion still occurred up to 62 percent of the time. So, a little can go a long way! Other studies have made similar findings. As reported by Natural Society: ⁵ 

“A similar conclusion was found by Dr. Anthony Di Pasqua, a bioinorganic chemist at the University of North Carolina and his colleague Dr. Fung-Lung Chung from Georgetown University. Their studies support Bhattacharya’s conclusions about AITC is brown mustard seed.

Dr. Di Pasqua said:⁶ ‘Our studies have shown that, once inside the cell, ITCs [isothiocyanates⁷] bind to proteins and that protein binding affinities are closely associated with the ability to induce apoptosis (cell suicide).’”

Myrosinase Is the Key to Maximizing Chemoprotective Effects of Cruciferous Veggies

ITCs are derivatives of sulfur-containing compounds called glucosinolates, found in cruciferous vegetables. Different glucosinolates hydrolyze into different ITCs. Broccoli, for example, is high in glucoraphanin, a glucosinolate precursor to sulforaphane, which has well-established chemoprotective effects.^8,9 Sulforaphane also helps improve blood pressure, heart health¹⁰ and kidney function. 

Scientists believe sulforaphane’s benefits are related to improved DNA methylation, which is crucial for normal cellular function and proper gene expression, especially in the easily damaged inner lining of the arteries (endothelium). Broccoli, like mustard seed, also contains sinigrin, the precursor to AITC.  As mentioned, glucosinolate hydrolysis is catalyzed by a class of enzymes called myrosinase. Plant sources known to be particularly high in myrosinase include:

Mustard seed	Garden cress	Wasabi	Daikon radish
Horseradish	Arugula	Coleslaw

To reiterate, the enzyme myrosinase is critical for the conversion of the various glucosinolates into ITCs¹¹ — the compounds that ultimately provide you with health benefits such as chemoprotection — and, while most if not all cruciferous veggies do contain some myrosinase, you can significantly boost the conversion by eating cruciferous vegetables together with a particularly myrosinase-rich food.

Doing so is a simple way to really maximize the chemoprotective effects of these vegetables. Wasabi, for example, has been shown to increase the chemoprotective effects of cruciferous vegetables by as much as 40 percent.¹²  

Mustard seed appears to be the most effective, however, as it contains a particularly resilient form of myrosinase. Research confirms mustard seed can boost sulforaphane formation even in boiled broccoli, which is typically not recommended as boiling prevents sulforaphane formation by inactivating the myrosinase in the broccoli.¹³