Unagi, or freshwater eel, is a popular ingredient in Japanese cuisine, most commonly served cooked and grilled as unagi sushi or unagi sashimi. However, there are potential health risks associated with consuming raw unagi, primarily related to parasites and foodborne illnesses. This article will examine if it is safe to eat raw unagi, the potential risks, how to cook unagi properly at home, and some popular cooked unagi dishes to try instead.
Is It Safe to Eat Raw Unagi?
Eating raw, untreated unagi does carry some health risks that need to be considered. Here are the main concerns with consuming raw freshwater eel:
- Parasitic infections. Freshwater eels like unagi can harbor parasitic worms and larvae that can infect humans when consumed raw or undercooked. Some common parasite species found in eels include nematodes, trematodes, cestodes, and acanthocephalans. These can cause gastrointestinal symptoms if ingested.
- Bacterial contamination and food poisoning. Like any raw meat, raw unagi also carries risks of bacterial contamination, such as Salmonella or Listeria. Foodborne illnesses from bacteria in raw unagi can lead to symptoms like nausea, vomiting, diarrhea, fever, and chills after ingestion.
- Toxins. Unagi contains an endogenous protein toxin called cylindrospermopsin, which is not destroyed by cooking. Eating raw unagi introduces higher levels of this toxin into the body and could potentially lead to liver damage over time with regular consumption.
- Allergic reactions. Some people may be allergic to freshwater eel and experience reactions like hives, itching, swelling, and anaphylaxis when eating raw unagi. Cooking unagi can help reduce these allergic proteins.
For these reasons, medical experts advise against consuming raw freshwater eel due to the potential parasitic, bacterial, and toxin risks. Pregnant women are especially cautioned against eating raw unagi.
How to Cook Unagi Safely
Cooking unagi properly can kill any parasites, bacteria, and reduce toxin levels to make it safe for consumption. Here are some tips for safely preparing unagi at home:
- Purchase fresh unagi from a reputable fish market or seller. Look for moist, shiny skin without any unpleasant odors.
- Store unagi in the refrigerator if cooking within 2 days, or freeze for later use. Thaw frozen unagi overnight in the fridge before cooking.
- Unagi needs to reach an internal temperature of at least 145°F to kill bacteria and parasites. The safest cooking methods are grilling, broiling, or roasting unagi.
- Grill or broil for 5-10 minutes per side, brushing with tare (grilling sauce). Roast at 400°F for 15-20 minutes until opaque and flaky.
- Always use a meat thermometer to check the internal temp, especially for thicker cuts. The center should reach 145°F.
- Cooked unagi can be safely stored for 3-4 days refrigerated. Reheat cooked unagi to 165°F before eating again.
Following safe cooking methods allows you to enjoy unagi while avoiding the biggest risks of consuming it raw. Grilling, broiling, and roasting unagi to the proper internal temperature helps reduce foodborne illness risks.
Health Benefits of Eating Cooked Unagi
In addition to being more safely consumed when cooked, preparing unagi properly also preserves more of its beneficial nutrients compared to eating raw. Here are some of the biggest health benefits of cooked freshwater eel:
- High in protein. A 3 oz cooked portion contains 25-30 grams of protein. Eating unagi can help meet daily protein needs.
- Rich in vitamins and minerals. Unagi provides B-vitamins like niacin, vitamin B12, and vitamin A. It also contains iron, selenium, zinc, potassium, and phosphorus.
- Source of omega-3 fatty acids. Although lower in fat than fatty fish, unagi does contain anti-inflammatory omega-3s like EPA and DHA.
- Collagen booster. Some studies suggest compounds like proline and glycine in cooked unagi may help improve skin elasticity and hydration.
Overall, enjoying cooked unagi in moderation can provide protein, important vitamins and minerals, omega-3s, and antioxidants as part of a balanced diet. Choosing cooked unagi optimizes these potential health benefits.
Popular Japanese Dishes with Cooked Unagi
Here are some classic Japanese recipes that feature grilled, broiled, or roasted unagi:
This dish consists of cooked unagi filets served over a bowl of steamed rice (donburi). It is typically garnished with sansho powder and served with a sweet soy dipping sauce. Unagi donburi allows you to taste the savory, smoky flavors of grilled eel.
Unagi Sushi Rolls
Slices of grilled unagi are layered in sushi rolls, such as the unakyu (eel cucumber roll) or unajobi (eel dried plum roll). The cooked eel is often brushed with a TERIYAKI-like glaze before serving.
Originating from the city of Nagoya, hitsumabushi features charcoal-grilled unagi over rice. It is served with chopped negi (Japanese leeks) and diced tamagoyaki (Japanese omelette) to be mixed together in the bowl and enjoyed.
This dish involves broiling or grilling unagi filets, coated in a sweet kabayaki tare sauce until caramelized and tender. Kabayaki unagi can be served over rice or noodles.
Shirayaki refers to unagi filets grilled without any sauce, to really highlight the natural flavor of the cooked eel. Shirayaki unagi allows you to taste the fat content and smoky notes.
When cooked properly, unagi can be the star ingredient in many tasty Japanese specialties ranging from donburi bowls to rolls and noodles. Choosing cooked preparations optimizes safety.
Is Unagi Sustainable? Conservation Considerations
With growing concerns about overfishing and threats to eel populations, there are certain sustainability issues to consider regarding unagi:
- Most unagi comes from wild-caught freshwater eels, which are decreasing in numbers globally due to factors like overfishing, habitat loss, and changes in ocean currents.
- The three main species used as unagi are the Japanese eel (Anguilla japonica), European eel (Anguilla anguilla), and American eel (Anguilla rostrata). All three are currently at risk and have declining wild stocks.
- Conservation groups recommend only purchasing unagi that has been raised in environmentally responsible aquaculture (eel farms) rather than wild-caught. Look for Aquaculture Stewardship Council (ASC) certification.
- Some organizations classify unagi as “avoid” when making sustainable seafood choices due to depleted wild populations.
- Farm-raised unagi can offer a more eco-friendly alternative to wild unagi but ensure the operations meet ASC standards for responsible practices.
- Some chefs use substitute sustainable fish like mackerel in place of unagi for certain rolls and dishes.
With careful sourcing from reputable aquaculture or substitutions when dining out, it’s possible to make sustainable unagi choices that are both ocean-friendly and safe when cooked thoroughly before eating.
Key Differences Between Freshwater Eel (Unagi) and Sea Eel (Anago)
When exploring Japanese eel cuisine, it’s important to understand the distinction between freshwater unagi and saltwater anago eels:
- Unagi refers specifically to freshwater eel species like the Japanese eel, European eel, and American eel. Unagi is usually farmed in freshwater lakes.
- Anago refers to saltwater conger eels which are a different genus and species than freshwater eels. Anago is fished from the ocean.
- On menus, unagi will usually be labeled as just “unagi.” Saltwater anago may be labeled as “anago” or “sea eel.”
- Unagi has a slightly sweeter, richer flavor compared to anago, which tastes comparatively brinier and mineral-like.
- Nutritionally, anago tends to be lower in fat and calories compared to the fattier unagi. Both are high in protein.
- Anago is not associated with the same parasite risks since it lives in seawater. It can be consumed raw as sashimi or in some raw preparations.
- Both unagi and anago are delicious grilled, but their flavor profiles differ slightly. Recipes tend to specify one variety or the other.
While closely related, there are noticeable taste and nutrition differences between Japanese freshwater eel and sea eel varieties. Understanding what you’re ordering can help inform menu choices.
Can You Substitute Other Fish for Unagi?
Some common substitutes for unagi in dishes include:
- Anago – Saltwater sea eel has a similar texture and flavor to unagi when grilled. It offers a brinier, mineral taste.
- Hamachi – Also known as yellowtail, hamachi has a fattier texture similar to unagi. Its flavor is less sweet.
- Aji – Spanish mackerel is a sustainable, economical option with a dense texture amenable to grilling.
- Saba – Mackerel is another great choice with a robust, savory grilled flavor.
- Shiromi – White fish like red snapper or branzino offer lighter flavors and tender flakes when cooked.
- Sake – Farmed salmon is an easy seafood swap and suitable for many unagi recipes.
- Tofu – Grilled tofu soaks up tare sauce flavors and mimics the protein of unagi in vegetarian dishes.
Testing out different substitute fish, depending on taste preferences and sustainability, can provide alternatives in enjoyed unagi recipes. Flavor, texture, and nutrition will vary.
In summary, while raw unagi does come with health risks from parasites, toxins, and bacteria, the freshwater eel offers many nutritional benefits when properly cooked at safe temperatures. Grilling, broiling, and roasting unagi helps reduce foodborne illness risks and enhances its natural flavor in Japanese dishes. Look for aquaculture-raised unagi or use substitutes to make sustainable choices. Overall, moderate consumption of fully cooked unagi can be an enjoyable part of a varied, seafood-rich diet when sourced and prepared properly.