When I was first asked to write an article about mizuna, I was a little embarrassed to admit that I had never actually heard of it. A quick WhatsApp group message to my foodie friends showed that I was not alone.
Only one of these erudite ladies had ever heard of mizuna. Even that one friend was not all that knowledgeable. She only vaguely remembered mizuna in the context of an ingredient for a salad that she could not find.
So, at this stage, I knew that mizuna had something vaguely to do with salads.
Next, I went to the Whole Foods website and found out that they don’t even stock mizuna.
This is my first time ever failing to find a product at Whole Foods.
Yet, despite this lack of preliminary data, it seems that some so-called ‘online wellness authorities’ claim that mizuna is good for inflammation, free radical damage, heart health, blood clotting, bones, immunity, cancer, and even eye health.
Before I poke a large hole in the ozone layer by importing mizuna across the globe with lots of food miles, maybe I should have a quick look at the science to see if it is actually worth it.
What is Mizuna?
Mizuna, or Brassica rapa var. niposinica, is a mustard plant. It typically has green frilly serrated leaves but also can have red or purple leaves. The relevance of the serration will become clear shortly.
It is also known as kyona, qian jing shui cai, kyo-mizuna, Japanese mustard, and California peppergrass.
It grows well in temperate climates and is tolerant of both heat and cold. According to some gardening websites, it is very easy to grow.
It can be eaten raw or lightly cooked. In the USA, mizuna is used more commonly in salads, while in Asia, it is used in soups and stir-fries.
The typical nutritional content of mizuna per 100 gm is
- Energy 2.4 kcal
- Protein 2.35 gm
- Lipid 0.59 gm
- Carbohydrate 3.53 gm
- Fiber 1.2 gm
- Sugar 2.35 gm
- Calcium 176 mg
- Iron 1.27 mg
- Sodium 29 mg
- Vitamin C 14.1 mg
- Vitamin A 2353 IU
- Fat 0 (1).
There are more than a hundred mizuna products for sale on Amazon, which are mostly seeds rather than the product itself. Even the Amazon search function did not believe that I actually wanted to find mizuna products and kept redirecting me to the Mizuna running gear brand.
Is There Any Research?
Deep breath required here. There are a grand total of 24 publications and no clinical trials on mizuna.
To put this into context, I have more publications on PubMed than mizuna.
Does Mizuna Fight Free Radical Damage & Inflammation?
There are no published studies, papers or articles on the effect of mizuna on free radical damage or inflammation.
Does it Promote Cardiovascular Health?
There are no published studies, papers or articles on the effect of mizuna on cardiovascular health.
Does It Support Blood Clotting?
There are no published studies, papers or articles on the effect of mizuna on blood clotting. Isn't this a fun article?
Does it Strengthen Bones?
There are no published studies, papers or articles on the effect of mizuna on bone strength.
Does It Improve Immune System?
There are no published studies, papers or articles on the effect of mizuna on the immune system. Yawn.
Does It Fight Cancer ?
Ok, finally something to talk about.
Brassica vegetables include broccoli, cabbage, mustard, collard greens, bok choy which contain glucosinolates which protect DNA from damage (2). Epidemiological studies have shown that consumption of Brassica vegetables is correlated with lower incidences of prostate cancer (2).
Another publication summarized the results of 7 cohort studies and 87 case-control studies on the association between brassica consumption and cancer risk (3). The cohort studies showed inverse associations between the consumption of cabbage, cauliflower, and broccoli and risk of lung cancer and stomach cancer.
This is very interesting and and gives me plenty of reasons to eat the specific vegetables mentioned in the studies which are cabbage, kale, broccoli, Brussels sprouts, and cauliflower. The studies do not mention mizuna.
This gives me two good reasons not to buy mizuna.
Firstly, it has not been proven to prevent cancer while other members of the brassica family have been shown to have benefits.
Secondly, as we now know, it is really hard to source mizuna.
Does It Promote Eye Health?
There are no studies.
At this stage, you may well be wondering, what on earth has been published on mizuna if there really are no clinical studies on mizuna?
One study reported on radioactivity in mizuna as part of on-going surveillance after the Fukushima Daiichi Nuclear Power Plant accident in March 2011 (4)
Another paper related to general experiments in calcium fortification (5).
The next paper mentioned mizuna in the context of development of a new mass spectrometry tool (the type of machine used in every episode of NCIS to analyze crime scene residue) (6).
The paper was looking at the measurement of flavonoids in a range of vegetables including mizuna. The study was carried out in the USA and I am guessing that the researchers must have grown their own vegetables for this experiment.
Researchers in Singapore looked at mizuna as a way to expedite commercial growth of other crops (7).
Japanese researchers used a mizuna greenhouse in the development of a low cost soil moisture probe (8).
All very interesting but not clinically relevant.
Are Mizuna Safe?
There is one single clinical publication on mizuna (9). The paper was published last year and reports the case of a 67 year old lady who was being investigated for prolonged, unexplained abdominal pain.
An upper gastrointestinal endoscopy showed that she had a sharp foreign body in her stomach wall. The offending object was removed and identified as a mizuna leaf. It seems that those serrations can cause problems.
We know almost nothing about mizuna. The only things that I can say for sure are that some mizuna contains some radioactivity, it is important to chew mizuna before swallowing and that some bloggers make things up.