ALEX CHADWICK, host:
This is DAY TO DAY, and this just in from the NPR science desk. Researchers have figured out why eating a dollop of wasabi makes you feel as those your head might explode. Wasabi is the green paste served with sushi. Lately, real wasabi's become rare. Some restaurants have switched to horseradish and green food coloring. No matter, the kick remains.
Scientists now understand how wasabi causes that almost pain, but as NPR's Joe Palca reports, they're not clear why people would subject themselves to it.
JOE PALCA reporting:
I'm at the Sushi Tower(ph) restaurant in Washington, D.C., and chef Nabou(ph) has just handed me a big glob of wasabi.
Chef NABOU (Sushi Tower): Don't take too much of it. Little piece.
PALCA: Whoa, that's hot!
What's happening is, compounds inside the wasabi called isothyocyanates are stimulating molecules called TRP receptors on the nerve cells in my mouth and tongue. These receptors play a key role in why we feel pain. They are they first step in a cascade of events that leads to a signal to the brain meaning ouch.
David Julius is one of the scientists studying the TRP receptors. He's at the University of California San Francisco. Julius believe that one of these TRP receptors, TRPA1, and only TRPA1, was the receptor that signaled the pain from isothyocyanates, so he bred some mice that didn't have that receptor.
Mr. DAVID JULIUS (Scientist, University of California San Francisco): What we found in this mouse is that it's completely deficient for its ability to respond to these pungent compounds. So this tells us that this TRPA1 is essential for the ability of the sensory nervous system to respond to these compounds.
PALCA: And it turns out that plants make a variety of compounds that stimulate TRP receptors.
Mr. JULIUS: Capsaicin from hot chili peppers or menthol from mint leaves or in this case, a series of compounds called isothyocyanate compounds from mustard plants.
PALCA: Presumably the reason plants started making these compounds was to make them taste bad, so humans or other animals wouldn't eat them. Not a complete success, but it was worth a try. If the TRP receptors' only role in life was to respond to unpleasant compounds found in nature, they wouldn't be all that interesting to study. But Julius has evidence that they're involved in a lot of pain from inflammation, like the kind you get from sunburn and arthritis.
Neuroscientist Steve McMahon agrees TRP receptors may be broadly important in pain. He's at King's College London.
Mr. STEVE McMAHON (Neuroscientist, King's College London): If they were only responsive to mustard oil, for instance, you'd have to say, Great, well, a drug that blocks TRPA1 would be a great analgesic for all those patients who happen to expose themselves to mustard oil. Well, that's not a big clinical problem.
PALCA: He says a better understanding of these TRP receptors could lead to a new class of painkillers for a variety of conditions. Of course, there are some people who do expose themselves to one of the ingredients in mustard oil, the isothyocyanates that are in horseradish or wasabi. Wasabi does cause pain, yet people gobble it up.
Part of the reason veteran sushi eaters don't suffer so much from wasabi's kick is that over time their TRPA1 receptors get less sensitive. Some food scientists think people eat hot foods to show off or because they get an endorphin rush from the pain, and a certain sensation of heat or even burning may enhance the flavor of food. Or, as perverse as it may sound, Steve McMahon says that people may just like pain.
Ms. McMAHON: Many people get some pleasure from mildly pain producing substances, and of course a subset of the population, they seem to get quite a lot of sexual pleasure as well. I mean, so that the associations of injury can give rise to pleasure, yes.
PALCA: Precisely why is still a matter for further inquiry. Joe Palca, NPR News, Washington.
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FAQs
Why is real wasabi so expensive? As the plant can only be grown in very specific environments, wasabi is one of the most expensive crops in the world. This is why a lot of people outside of Japan may have never actually tasted real wasabi before.
What is the science behind wasabi? ›
The unique flavour of wasabi is a result of complex chemical mixtures from the broken cells of the plant, including those resulting from the hydrolysis of thioglucosides, including sinigrin and other glucosinolates, into glucose and methylthioalkyl isothiocyanates: 6-(Methylsulfinyl)hexyl isothiocyanate (6-MITC)
Why is wasabi addictive? ›
Wasabi has an umami flavour with an additional sharp, fiery heat which can be quite addictive.
What happens to your body when you eat wasabi? ›
Wasabi contains chemicals that may have anticancer effects and anti-inflammatory effects and may also slow blood clotting. People take wasabi by mouth for heart disease, cancer, stomach pain, indigestion, and many other conditions, but there is no good scientific evidence to support these uses.
Is real wasabi hotter than fake wasabi? ›
Real wasabi is not spicy. It's more like the aroma of spiciness but without the pungent punch of the mustard seed flour in the fake stuff. Fake wasabi has a very strong taste that overrules the delicate fish taste. It delivers a strong blast of spiciness that comes from the mustard seed flour.
Do Japanese restaurants use real wasabi? ›
Yamamoto says it's difficult to describe the taste of true wasabi, but that its sour and pungent spice should be balanced by an underlying sweetness and herby smell. Mind you, you might never try the real stuff, since 95 percent of Japanese restaurants offer fake wasabi, even in Japan.
Is wasabi healthy for you? ›
Yes, wasabi is healthy! This powerful green root is packed with nutrients, including vitamin C, potassium, and calcium. It also contains antioxidants and compounds that can help protect your body against inflammation and chronic diseases.
How expensive is real wasabi? ›
While this may be true to some extent, the BBC reported that a kilo of wasabi, which translates to just over two pounds, fetched $160 in 2014. A 2019 Bustle article places the price for the same amount at $250. Wasabi's extreme cost, which prompted Barron's to dub the root "green gold," is pretty normal then.
How long does real wasabi last? ›
The rhizomes keep fresh for at least three weeks in the refrigerator. The quality is nearly completely unaffected if stored correctly. Rhizomes stored properly can be used for two months or more. However, once it's grated, the heat and flavor evaporate from the paste in about half an hour.
Is it bad to eat wasabi everyday? ›
But even when one is consuming genuine wasabi, it's not all good news. Zumpano cautions that consuming large amounts of wasabi can irritate one's nose, stomach, or mouth, and increase risk of bleeding or bruising. Therefore, she says one shouldn't eat wasabi if taking blood thinners or within two weeks of any surgery.
The bottom line
The compounds in wasabi have been analyzed for their antibacterial, anti-inflammatory, and anticancer properties in test-tube and animal studies. They have also been researched for their ability to promote fat loss, as well as bone and brain health.
Does wasabi clear sinuses? ›
That dollop of wasabi on your sushi may feel like a blast of decongestant, but researchers have found that it does not really clear the sinuses. In fact, the researchers report, the condiment, often called Japanese horseradish, actually causes a bit of congestion.
Which wasabi is the healthiest? ›
Wasabi that comes from the stem of the wasabi plant is in fact healthier than the wasabi paste prepared with horseradish. Authentic wasabi contains more fiber and potassium than the more commonly prepared restaurant version.
Is wasabi good for your liver? ›
Notably, these compounds exhibit antioxidant properties, helping neutralize free radicals and reduce oxidative stress on liver cells. Additionally, the anti-inflammatory effects of Wasabia japonica may contribute to mitigating liver inflammation, potentially preventing liver diseases.
Is wasabi bad for high blood pressure? ›
While wasabi's spice might get your heart beating, some components in wasabi actually do promote heart health. Adding a bit of wasabi to your diet can help reduce cholesterol and improve blood circulation, which ultimately keeps your blood pressure at a healthy level.
Can you get real wasabi in the USA? ›
Real wasabi in the US is rare, and most products out there are a mix of horseradish, Chinese mustard, and food coloring. Don't settle for less.
How rare is real wasabi? ›
Actual wasabi is extremely rare and, in turn, extremely expensive. It can cost up to $250 for one kilogram of wasabi. (That's a little more than 2.2 pounds for those of us who still use the imperial system.) That's reason number one why it's hard to come by.
Can you grow wasabi in the United States? ›
Wasabi cultivation In North America has been successful in the rain forests found on the Oregon Coast and in parts of the Blue Ridge Mountains in North Carolina and Tennessee provide just the right balance of climate, sunlight and water quality to grow natural wasabi.
