Does Tuna Raise Potassium? Understanding Tuna's Potassium Content

November 14, 2025 •

4 min read

According to the National Kidney Foundation, tuna is a kidney-friendly protein source for most individuals, and yes, tuna does contain potassium. However, whether it raises your levels significantly depends on factors like portion size, preparation, and your overall health needs, especially kidney function.

Quick Summary

Tuna is a good source of potassium, but the amount varies by type and preparation. Canned tuna, particularly light tuna, contains less potassium than fresh tuna and can be high in sodium, which is also a consideration for certain health conditions. Moderation and preparation methods are key for managing potassium intake from tuna.

Key Points

Tuna contains potassium: Both fresh and canned tuna provide potassium, but the quantity varies significantly depending on the type and preparation.
Fresh tuna is higher in potassium: Fresh tuna, like yellowfin, generally has a higher concentration of potassium than canned tuna.
Canned light tuna is lower in potassium: Canned light tuna, often from skipjack, contains less potassium and mercury than canned albacore.
Drain and rinse canned tuna: For those monitoring potassium, draining and rinsing canned tuna is a simple way to reduce its mineral content.
Consider sodium in canned tuna: Canned tuna can be high in sodium, which is a factor to consider alongside potassium for individuals with high blood pressure or kidney issues.
Moderation is key for kidney health: Individuals with kidney disease need to monitor their intake and consult a dietitian, as high potassium can be dangerous for them.

The Basics of Potassium in Tuna

Potassium is a vital electrolyte that plays a crucial role in maintaining fluid balance, nerve signals, and muscle contractions. Most Americans don't get enough potassium, but for individuals with specific health concerns, such as kidney disease, managing intake is crucial. Tuna is an animal-based source of this mineral, and understanding its content can help you make informed dietary choices.

Potassium Content: Fresh vs. Canned Tuna

The amount of potassium in tuna varies depending on whether it's fresh or canned, and even the type of tuna and canning liquid. A 100g serving (about 3.5 ounces) of cooked fresh yellowfin tuna contains roughly 449 mg of potassium. In contrast, a 100g serving of light canned tuna in water, drained, has a significantly lower amount, around 176 mg.

Fresh Tuna: Often has a higher concentration of potassium per serving, similar to other fresh fish like salmon or mackerel.
Canned Tuna: The canning process can impact the mineral content. Draining the liquid from canned tuna can also affect the final potassium and sodium levels, which is important for people on restricted diets. Some sources of canned tuna, like those packed in oil, may also have different nutritional profiles.

Factors Influencing Your Body's Potassium Levels

While tuna contributes to your daily potassium intake, it's a piece of a much larger puzzle. Your overall dietary pattern and individual health status are far more significant factors in determining your body's potassium levels. For a healthy individual with normal kidney function, consuming a moderate amount of tuna is unlikely to cause a potassium imbalance. The body is very efficient at regulating potassium, excreting excess through the urine.

Comparing Potassium in Tuna and Other Foods

To put tuna's potassium content into perspective, it's helpful to compare it with other common food sources. While fresh tuna is a good source, many fruits, vegetables, and legumes contain even higher concentrations of potassium.


Food (100g Serving)	Potassium (approx. mg)	Comparison to Fresh Tuna
Baked Potato (with skin)	583	Higher
Avocado	485	Higher
Fresh Tuna (Yellowfin)	449	Baseline
Cooked Salmon	439	Similar
Canned Tuna (Light, in water, drained)	176	Lower
Banana	358	Lower (though often perceived as very high)

Tuna and Special Dietary Considerations

For the average person, consuming tuna is a safe and healthy way to get potassium. However, some individuals need to be mindful of their potassium intake. This is especially true for those with chronic kidney disease (CKD), whose kidneys may not be able to effectively filter excess potassium. A buildup of potassium (hyperkalemia) can be dangerous. For these individuals, a renal dietitian or healthcare professional can provide personalized advice.

Kidney Disease: For those in later stages of CKD, monitoring potassium intake from all sources, including fish, is important. Opting for canned light tuna over fresh and controlling portion sizes can help.
Sodium Content: Canned tuna, especially those packed in brine, can be high in sodium, which is another concern for individuals with kidney disease or high blood pressure. Choosing low-sodium varieties or rinsing the tuna can mitigate this.
Other Conditions: People taking certain medications, such as some diuretics or ACE inhibitors, may also need to monitor potassium intake. Consulting a doctor is always recommended.

How to Incorporate Tuna into a Balanced Diet

Including tuna in your diet can be done strategically to manage your potassium intake while still reaping its numerous health benefits, such as high protein and omega-3 fatty acids.

Choose the Right Type: If you are monitoring potassium, choose canned light tuna over fresh or albacore tuna.
Rinse Canned Tuna: Rinsing canned tuna under water can help to further reduce both its sodium and potassium content.
Practice Portion Control: Be mindful of your serving size. While tuna provides potassium, a standard serving size is unlikely to significantly spike levels in a healthy individual.
Balance with Other Foods: Pair tuna with low-potassium vegetables like cucumbers or bell peppers. Avoid pairing it with other high-potassium foods like potatoes or bananas in the same meal if you're on a restricted diet.
Use Low-Sodium Products: When making tuna salad, use low-sodium mayonnaise or yogurt as an alternative to control overall sodium levels.

Conclusion

In summary, tuna does contain potassium, with fresh varieties typically having more than canned light tuna. For healthy individuals, this is a positive contribution to a nutrient-rich diet. For those with kidney disease or other conditions requiring potassium management, tuna consumption needs to be monitored, with a preference for canned light, drained tuna and careful attention to portion size. Always consult with a healthcare provider or renal dietitian for personalized dietary advice to ensure your intake aligns with your health needs.

Visit the National Kidney Foundation for more information on diet and kidney health.

Frequently Asked Questions

While tuna does contain potassium, it is not considered one of the highest sources, especially canned light tuna. Many fruits and vegetables, like potatoes and spinach, contain significantly more potassium per serving.

Yes, people with kidney disease can often eat tuna, but they should do so in moderation and under the guidance of a doctor or renal dietitian. Choosing canned light tuna and rinsing it can help manage potassium and sodium intake.

Yes, draining the liquid from canned tuna can lower its potassium and sodium levels. For those on restricted diets, this simple step can be beneficial.

Fresh tuna generally has a higher potassium content than canned tuna. For example, a 100g serving of fresh yellowfin can have over 400 mg, while the same amount of canned light tuna has less than 200 mg.

Light tuna (often from skipjack) is a better choice for managing potassium, as it typically has lower levels than albacore tuna.

Canned tuna can be high in sodium, which can influence fluid balance and blood pressure, an important consideration for individuals needing to monitor potassium. It's best to choose low-sodium canned tuna to manage both.

If seeking higher potassium sources, alternatives include salmon, mackerel, potatoes, spinach, and beans. For those on a low-potassium diet, low-potassium meats and fish like clams and oysters are options.