Is it healthy to eat canned tuna in water? A complete nutritional guide

December 10, 2025 •

4 min read

According to the USDA, a 5-ounce can of tuna in water contains approximately 120 calories and is a rich source of protein. The question of whether it is healthy to eat canned tuna in water is a common one, and the answer involves balancing its nutritional benefits against potential risks like mercury content.

Quick Summary

This article evaluates the benefits and risks of consuming canned tuna packed in water, detailing its nutritional profile, comparing it to tuna in oil, and providing guidance on managing mercury exposure for safe consumption.

Key Points

Nutrient-Dense Protein: Canned tuna in water is an excellent source of high-quality, lean protein that supports muscle health and satiety for weight management.
Lower Calorie and Fat Count: Packed in water, this tuna is significantly lower in calories and fat compared to its oil-packed counterpart, making it ideal for calorie-conscious diets.
Rich in Omega-3s: Water-packed tuna provides beneficial omega-3 fatty acids (EPA and DHA) that are crucial for heart and brain health.
Mindful of Mercury: To minimize mercury exposure, opt for canned light (skipjack) tuna, which has lower levels than albacore (white) tuna.
Consume in Moderation: While nutritious, canned tuna should be consumed in moderation as part of a varied diet, with specific recommendations for sensitive populations like pregnant women.
Important Vitamins and Minerals: A single can delivers essential nutrients such as Vitamin B12, Vitamin D, and Selenium.
Choose Low-Sodium Options: To control sodium intake, select low-sodium or no-salt-added versions when possible.

The Nutritional Powerhouse in a Can

Canned tuna packed in water is celebrated as a convenient, affordable, and lean source of protein that is readily available. For individuals aiming to increase their protein intake without adding excessive calories or fat, it is an excellent pantry staple. A typical serving provides high-quality protein, which is vital for building and repairing muscle tissue, promoting satiety, and managing weight. Beyond its protein content, canned tuna offers a wealth of other essential nutrients.

Essential Vitamins and Minerals

This simple tinned fish is packed with a variety of vitamins and minerals that support overall bodily function. These include:

Vitamin B12: Crucial for nerve function and the production of red blood cells.
Vitamin D: Many people are deficient in this vitamin, which supports the immune system and bone strength.
Selenium: A powerful antioxidant that plays a role in thyroid function and immune health.
Niacin (B3): Important for energy production and a healthy nervous system.
Iron: Necessary for oxygen transport throughout the body.

Heart-Healthy Omega-3 Fatty Acids

Despite being low in total fat, canned tuna is a source of heart-healthy omega-3 fatty acids, specifically EPA and DHA. While omega-3 levels can vary depending on the packing liquid, choosing and properly draining tuna in water can help maximize this benefit. These fatty acids are known to reduce inflammation, lower the risk of heart disease, support brain function, and help maintain healthy blood pressure levels.

Water vs. Oil: The Nutritional Showdown

One of the most common questions regarding canned tuna is whether to choose water or oil packing. The choice significantly impacts the nutritional profile, texture, and flavor of the final product. Here is a comparison to help you decide which is best for your dietary goals:


Feature	Water-Packed Tuna	Oil-Packed Tuna
Calories	Significantly lower, around 116 calories for a 4-ounce serving.	Higher calorie count due to added oil, typically around 200-210 calories for a 4-ounce serving.
Fat Content	Very low in fat, making it an excellent choice for those managing calorie intake.	Higher in total fat, as the oil infuses into the fish during storage.
Omega-3s	Retains a good amount of omega-3s, especially if drained properly, as the fish's natural fatty acids are not lost to a different oil.	Some omega-3s are lost when the packing oil is drained, though the oil itself can contain some fatty acids depending on the type used.
Texture	Tends to have a firmer, flakier texture, making it ideal for dishes where the fish holds its shape.	Features a softer, more succulent texture, which can be richer and more palatable for some recipes.
Flavor	Milder, cleaner, and more subtle fish flavor, allowing it to take on the taste of other ingredients.	Richer, more savory flavor that is influenced by the type of oil used for packing.
Weight Loss	A better choice for weight management due to lower calorie and fat content.	Less suitable for calorie-restricted diets due to higher fat and calorie count.

Addressing the Mercury Concern

One of the most persistent health concerns surrounding tuna consumption is its mercury content. All tuna contains methylmercury, a neurotoxin that accumulates in fish and can be harmful if ingested in excessive amounts over time. The level of mercury in canned tuna, however, is not uniform and depends on several factors, most notably the species of tuna.

Choosing for Lower Mercury

There are two main types of canned tuna: chunk light and solid or chunk white (albacore).

Canned Light Tuna: This is typically made from smaller skipjack tuna. These fish have a shorter lifespan and are lower on the food chain, resulting in significantly lower mercury levels than albacore.
Canned Albacore Tuna: This is from larger albacore tuna, which accumulate more mercury over their longer lifespan.

Health experts recommend that most adults can safely eat canned light tuna several times a week, while intake of albacore should be more limited. Groups particularly sensitive to mercury, such as pregnant or breastfeeding women and young children, have stricter recommendations and are often advised to prioritize lower-mercury seafood options.

Practical Tips for Safe and Healthy Consumption

To reap the health benefits of canned tuna while minimizing risks, follow these practical guidelines:

Diversify your protein sources: Don't rely solely on canned tuna for your seafood intake. Incorporate a variety of other low-mercury fish, such as salmon, sardines, and cod, into your diet.
Opt for canned light tuna: Choose canned light (skipjack) tuna most often for its significantly lower mercury content compared to albacore.
Select low-sodium versions: Canned tuna can be high in sodium. Look for low-sodium or no-salt-added options, especially if you are monitoring your blood pressure.
Check for BPA-free cans: Some consumers prefer to choose brands that use BPA-free can linings to avoid potential chemical exposure, although more research is needed on its long-term effects.
Incorporate healthy ingredients: Pair your canned tuna in water with fiber-rich foods like whole grains, vegetables, and beans to create a well-rounded, balanced meal.

Conclusion: A Healthy Addition in Moderation

So, is it healthy to eat canned tuna in water? Yes, absolutely. Canned tuna packed in water is a highly nutritious and convenient food, offering a powerful dose of lean protein, essential vitamins, and heart-healthy omega-3s. For those focused on weight management, its lower calorie and fat content compared to oil-packed varieties makes it a superior choice. The key to healthy consumption, however, lies in moderation and making informed decisions about the type of tuna you purchase.

By opting for lower-mercury varieties like canned light (skipjack) tuna and diversifying your protein sources, you can enjoy all the benefits with minimal risk. When consumed mindfully and as part of a balanced diet, canned tuna in water can be a valuable and delicious component of a healthy lifestyle. For further information on FDA guidelines for mercury levels in fish, visit their official website.

Frequently Asked Questions

Tuna packed in water is generally considered healthier for weight management as it is lower in calories and fat compared to oil-packed tuna. However, both are good sources of protein and omega-3s, and the choice depends on your specific dietary needs.

For most healthy adults, consuming one to three servings (about 4 ounces each) of canned light (skipjack) tuna per week is generally safe. For canned albacore, which has higher mercury, limits are stricter.

While canned tuna contains methylmercury, the levels in canned light (skipjack) tuna are low enough that moderate consumption is considered safe for most people. Large, predatory fish like albacore contain more mercury and should be consumed less frequently.

Yes, but they should be mindful of the type and amount. The FDA advises that pregnant or breastfeeding individuals can enjoy two to three servings per week of low-mercury options, such as canned light tuna. They should limit or avoid higher-mercury albacore.

Yes. With its high protein and low-calorie count, canned tuna in water promotes satiety and is a valuable component of a weight loss diet. The protein helps you feel full for longer, which can reduce overall calorie intake.

Draining canned tuna packed in oil can remove some omega-3 fatty acids that have leached into the oil. When draining water-packed tuna, the natural fish fats (including omega-3s) are better retained.

For the lowest mercury content, choose canned light or skipjack tuna. Look for brands that are certified for sustainability, and consider 'no salt added' varieties if you are monitoring sodium intake.

Yes, canned tuna in water is a source of omega-3 fatty acids like EPA and DHA. While the amount can vary, it is still a beneficial contributor to your omega-3 intake.