Sushi isn’t just a delicacy, it’s practically an art form. With humble roots, starting as a way to preserve fish in Japan, this cuisine has become an immensely popular and sophisticated dish across America.
At its baseline, sushi seems like a healthy, nutritious meal: rice, veggies, fresh fish—but past that, there are many different variations as to how sushi can be prepared, and which ingredients are used. Here, registered dietitians weigh in on the health benefits of sushi, and how to get the most out of your order.
Sushi is a collection of rice, vegetables, and cooked or raw fish wrapped up in a roll of seaweed. There are typically three types of sushi, and they include nigiri, maki, and temaki. Nigiri is raw fish, salmon eggs, cooked shrimp, or sliced egg on rice. Maki is rolled sushi. Temaki, or a handroll, is sushi rolled by hand into a cone shape. The variance of ingredients in these types of sushi is where the question of health begins to surface.
“To make sushi, [vinegar-saturated] rice is hand-molded and topped with raw fish or other seafood,” Ella Davar, RD, CDN, a registered dietician integrative nutritionist and certified health counselor based in Manhattan, told Health. “Vinegar is added to cooked rice to achieve a pH of 4.6 or less, depending on the chef’s preference.”
Chefs may add sugar, salt, or both, to make the rice sweeter and more palatable, said Davar.
“In the rolled variant (maki),” added Davar, “a special bamboo mat is used, and nori (a thin sheet of prepared seaweed) is wrapped around the rice and fillings such as [egg], avocado, mango or cucumber.” Nori is full of nutrients such as folic acid, niacin, calcium, and vitamins A, C, and K.
While sushi has many healthy elements, how it’s prepared and seasoned can take away from the overall nutrition. For example, Marisa Moore, RDN, a registered dietitian nutritionist based in Atlanta, told Health that rolls dipped in tempura and fried [and] then covered with a creamy sauce will not be the same as those wrapped solely in nori and packed with fish, rice and vegetables.”
In terms of health and longevity, the Japanese diet has significantly contributed to longer lifespans, and that’s in part due to the fish they eat, many of which are high in EPA and DHA fatty acids and are found in different types of sushi.
If you’re looking for what to order, Davar recommended opting for nigiri or sashimi, which has raw fish slices and pairing it with a side salad or cooked veggies.
“The idea is to see more colors from various fish and veggies and less white color of cooked vinegared rice,” stated Davar. “In addition to the regular rice-wrapped roll, I like to order ‘Naruto-style’ which is a roll wrapped in cucumber. It is fun, crunchy, and makes a great healthy option in addition to traditional sushi menu options.”
However, if you’re gunning for rolled sushi, try to use healthier types of fish like salmon and Pacific chub mackerel, which are low in mercury. Avoid King mackerel which is high in mercury. Additionally, choose low-sodium soy sauce and go for other healthy flavor enhancers like wasabi or pickled ginger (gari).
The various combinations of different vegetables and fish have enriching benefits—especially with additives like wasabi and pickled ginger—but what exactly do all those flavorful ingredients do for your body?
It May Help Improve Gut Health
Research suggests that fermented foods like bok choy, seaweed, mushrooms, kimchi, natto, and tofu—all of which may be inside or accompany sushi—may strengthen your gut microbiome, which is the millions of bacteria, viruses, and fungi that live in the digestive tract.
Take a study from 2021. In that study, published in Cell, researchers found that 18 people who ate a diet high in fermented foods for 10 weeks increased the diversity of their gut microbes. The researchers wrote that a diverse microbiota is something that has long been associated with improved health and well-being.
It Can Strengthen Your Immune System
The same Cell study may have also proven something scientists have long believed: Consuming fermented foods reduce inflammation.
Chronic inflammation, which is the immune’s systems healing response to infection or injury, can lead to diseases such as arthritis or Type 2 diabetes. After the study participants ate a diet rich in fermented foods, they had a reduction in inflammatory proteins in their cells.
It May Help Improve Your Heart Health
Salmon and mackerel are excellent sources of protein in addition to DHA omega-3 fatty acids, which are a group of polyunsaturated fats. Some observational studies and meta-analyses have shown a link between consuming omega-3s and a reduced risk of coronary heart disease, but it’s important to note that results from clinical trials have been mixed.
It Boosts Thyroid Function
The nori most commonly used to make sushi is extremely nutritious. It offers vitamins C and A, iron, and protein, and is an excellent source of folate, which your body needs to produce DNA.
Nori—as well as other types of seaweed—is one of the best sources of iodine, which the thyroid gland relies on to make hormones that play an important role in metabolism, cell repair, and other important functions. According to a study published in 2014 in the Journal of Food and Drug Analyses, just one gram of nori contains anywhere from 30 to 40 mcg of iodine, which is about a quarter of the recommended daily intake.
Sushi can be a healthy option, but this delicacy is not without its faults, and with the benefits come a couple of risks to be considered as well.
It Can Lead to High Sodium Intake
Part of what makes sushi so flavorful is the high concentration of salt. The rice, fish, and even seaweed all come into contact with salt during the preparation process, and that’s before adding soy sauce.
The main problem with sodium is that it attracts water, and a high-sodium diet draws water into the bloodstream, which can increase the volume of blood and subsequently your blood pressure.
Your body tries to dilute the sodium and retains more water, which increases your overall blood volume. This leads to your blood vessels working overtime to pump all of that blood, and that pressure can stiffen blood vessels, resulting in high blood pressure, heart attack, stroke, and even heart failure. Key takeaway? Take it easy with the salt.
It Adds More Refined Carbs to Your Diet
White rice is a big part of sushi. It’s a refined carbohydrate, meaning it includes sugars and has been stripped of nutrients. Brown rice, on the other hand, is a whole grain—meaning that it still contains all parts of the grain (the bran, germ, and endosperm), which are rich in nutrients.
Studies have shown that an increased intake of refined carbs has contributed to the prevalence of type 2 diabetes in the U.S. White rice has a high sugar content which can lead to overeating due to spikes in blood pressure and insulin levels.
It May Add Unsafe Levels of Mercury to Your Diet
The top fish you should avoid due to their high mercury content are King mackerel, marlin, orange roughy, shark, swordfish, tilefish, ahi tuna, and bigeye tuna.
“Tuna has gotten a bad reputation due to [its] high mercury content; however, it depends on the type of tuna,” stated Davar.
Experts recommend swapping ahi (yellowfin) and bigeye tuna, which accumulates the most mercury over its lifetime, for a light tuna or skipjack tuna. If you’re willing to skip tuna altogether, you can opt for lower-mercury fish and shellfish like eel, salmon, crab, and clam.
It Puts You at Risk for Foodborne Illness
Food preparation can make a huge difference in terms of health and food safety. Most cooking requires high heat to eliminate food contaminants like pathogens, but with sushi, this step doesn’t happen.
Davar noted that one of the biggest hazards of consuming uncooked, undercooked, or frozen seafood is the parasites, which can grow naturally in many animals and be transmitted to and cause illness in humans.
The U.S. Department of Health & Human Services recommends that anyone with weakened immune systems, pregnant people, and older adults cook food thoroughly, which means avoiding raw fish.
There are ways to minimize the risk of foodborne illness when dealing with raw and undercooked fish.
“Always purchase your sushi from a reputable restaurant, or if you’re making it yourself, seek out a fishmonger that provides sushi-grade fish that’s been handled and sold specifically for sushi,” suggested Moore.
Plainly, some elements of sushi are fabulous for your health, and some elements are less than stellar. As Moore put it, “Not all sushi is created equal, and it can vary from place to place.” That being said, if you absolutely love sushi, there are ways to make it healthier.
“Instead of relying on names, take a look at what’s inside [the sushi] as well as the sauces,” stated Moore. “Go for rolls with your favorite seafood, and vegetables such as cucumber and carrots, and add creaminess from the avocado.”
You can also ask whoever is preparing your sushi to use less rice than normal, said Davar, “to prevent blood sugar spikes due to high carbohydrate load from white rice and sweetener used to make it.”
Sushi is a collection of rice, vegetables, and cooked or raw fish that can pack a nutritious punch. Research suggests that eating sushi may boost everything from gut health to thyroid and immune function. But there are some downsides to chowing down on sushi: White rice is a refined carbohydrate, and sushi generally has a high salt content.
If you’re looking to optimize health, keep it simple by sticking to sauce-free sushi that contains only your favorite seafood and a couple of veggies. Satisfy your craving for creaminess with avocado.
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