Wasabi paste — or more simply, "wasabi" — is produced by grating the stem of the wasabi plant (the wasabi rhizome). When this stem is grated, the plant's components break down almost immediately, resulting in a paste-like substance. Wasabi is most commonly served in Japan alongside sushi, sashimi, and nigiri dishes.
Wasabi paste is actually quite expensive. Not only are wasabi plants rare and costly, but wasabi paste also has a short shelf life. For these reasons, most wasabi served in sushi restaurants in the United States does not contain real wasabi.
Instead, producers combine horseradish, mustard flour, cornstarch, and green food colorant to create a product that captures the flavor and look of authentic wasabi. This “fake” wasabi is cheaper and has a much longer shelf-life than authentic wasabi. Interestingly, wasabi paste made with horseradish is much spicier than wasabi paste that comes from the plant.
Most of the wasabi served outside Asia can be classified as inauthentic and contains no actual wasabi plant material {Corson, T. The Story of Sushi: An Unlikely Saga of Raw Fish and Rice. 2008. HarperCollins.}. We’ll take a look at the health benefits of the horseradish-based version of wasabi you’re most likely to encounter.
Nutrition Information
One teaspoon of horseradish-based wasabi paste contains:
- Calories: 15
- Protein: 0 grams
- Fat: 1 gram
- Carbohydrates: 2 grams
- Fiber: 0 grams
- Sugar: 2 grams
Wasabi paste also contains small amounts of:
At about one teaspoon, a serving of wasabi is so small that there are few measurable nutrients.
Potential Health Benefits of Wasabi
Wasabi paste itself is not high in nutrients, but it is often served alongside nutritious fish-based dishes like sushi, sashimi, and nigiri.
Research has also found a number of potential health benefits associated with the nutrients found in horseradish-based wasabi paste:
Lower Risk of Anemia
Wasabi contains a small amount of iron. Getting enough iron in your diet lowers your risk of developing anemia, a condition that causes symptoms like fatigue, heart palpitations, and other issues related to blood iron levels. Iron impacts the level of hemoglobin in the blood, which is necessary for delivering oxygen throughout your body.
Lower Blood Pressure
Wasabi contains a small amount of potassium. Research shows that diets rich in potassium can have a positive impact on blood pressure. When participants in a study on potassium took in around 4,100 mg of potassium each day, their blood pressure readings were lower than participants who took in less.
Potential Risks of Wasabi
The wasabi paste served in most restaurants in the Western world contains a high level of sodium relative to its one teaspoon serving size. If you follow a low-sodium diet, you should limit how much wasabi you eat.
Soy Allergy
Most “fake” wasabi contains soybean oil. If you have a soy allergy, you should avoid wasabi unless you are confident that it is authentic and contains no soy products.
Healthier Alternatives
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. However, since we consume wasabi in such small quantities, there is little nutritional difference between the two versions.
