Which vegetable is the lowest in potassium?

October 28, 2025 •

3 min read

For those managing conditions like kidney disease, controlling dietary potassium is crucial, with the typical goal being between 1,500 and 2,000 milligrams per day. This guide reveals which vegetable is the lowest in potassium and offers practical tips for managing intake.

Quick Summary

This article explores and identifies the vegetables with the lowest potassium content, crucial for individuals on a restricted diet. It examines comparative data, discusses cooking methods to further reduce potassium levels, and provides lists of low-potassium vegetables to incorporate into meals for better health management.

Key Points

Radishes have exceptionally low potassium: A single medium radish contains only about 10 mg of potassium, making it a leading choice for a very low-potassium diet.
Iceberg lettuce and cucumbers are also top contenders: Iceberg lettuce offers a low-potassium base for salads, and cucumbers, mostly water, are naturally low in the mineral.
Preparation methods affect potassium content: Boiling and soaking vegetables can significantly reduce their potassium levels, a process known as leaching.
Beware of high-potassium vegetables: Foods like potatoes, tomatoes, and cooked spinach are high in potassium and should be consumed in moderation or prepared carefully on a restricted diet.
Consult a healthcare professional: For a personalized diet plan tailored to specific health conditions, it is always recommended to consult with a doctor or registered dietitian.

Understanding Potassium and Dietary Needs

Potassium is an essential mineral and electrolyte that plays a vital role in maintaining the body's fluid balance, nerve signals, and muscle contractions. For most healthy individuals, regulating potassium levels is not a concern, as the kidneys effectively manage the excess. However, for people with chronic kidney disease (CKD) or those on certain medications, excess potassium can build up in the blood, a potentially dangerous condition known as hyperkalemia. Knowing which vegetables are naturally low in this mineral is a cornerstone of managing such dietary requirements.

The Top Contenders: Which Vegetables Have the Least Potassium?

Determining the absolute lowest potassium vegetable can depend on serving size and preparation. However, several vegetables consistently rank at the bottom of the list for potassium content, making them excellent choices for a low-potassium diet.

Radishes and Iceberg Lettuce

Raw radishes are exceptionally low in potassium, with just about 10 mg per medium radish. Their minimal potassium count, combined with their crunchy texture, makes them a perfect, guilt-free addition to salads. Similarly, iceberg lettuce is famously low in nutrients, including potassium, containing only about 77.55 mg per cup, shredded. While it may not be the most nutrient-dense green, it provides a safe, crisp base for salads and wraps on a restricted diet.

Cucumbers and Other Low-Potassium Favorites

Cucumbers, composed mostly of water, are another excellent low-potassium choice. A cup of peeled, chopped cucumber contains approximately 181 mg of potassium, with one cup of slices containing just 76 mg. The discrepancy comes from preparation, as peeling and slicing removes some mineral content. Other reliable options include raw white mushrooms, yellow squash, and canned water chestnuts, all with very low potassium counts per half-cup serving.

Low-Potassium Vegetable Comparison

To help visualize the best choices, here is a comparison table of several low-potassium vegetables and their content per standard serving.


Vegetable (Serving)	Preparation	Potassium Content (mg)	Source
Radish (1 medium)	Raw	10	DaVita
Iceberg Lettuce (1 cup shredded)	Raw	77.55	University of Rochester
Cucumber (1/2 cup slices)	Raw	76	Food Network
Cauliflower (1/2 cup)	Cooked, boiled	88.04	University of Rochester
Green Beans (1/2 cup)	Cooked, boiled	115	DaVita
Cabbage (1 cup shredded)	Raw	172.2	University of Rochester
Onions (1/2 cup)	Raw or boiled	175	Western Health

Strategic Preparation to Minimize Potassium

For those who enjoy vegetables with slightly higher potassium, like potatoes or spinach, specific preparation methods can significantly reduce their mineral content. A process known as "leaching" involves soaking or boiling vegetables to draw out the water-soluble potassium.

To effectively leach vegetables:

Peel and cut vegetables into thin pieces.
Soak the pieces in a large volume of warm water for at least two hours, or even overnight.
Drain the soaking water, rinse thoroughly, and cook in fresh, potassium-free water.

Studies have shown that this method can remove a significant portion of the potassium, making these foods safer for a restricted diet. For canned vegetables, simply draining and rinsing is effective for removing some excess minerals.

High-Potassium Vegetables to Limit or Avoid

For context, it is also useful to know which vegetables are typically high in potassium and should be limited. These include:

Potatoes (especially baked with skin)
Sweet potatoes
Spinach (cooked)
Tomatoes and tomato products (juice, sauce)
Acorn and butternut squash
Artichokes
Beets

Planning a Balanced Low-Potassium Diet

While focusing on low-potassium vegetables is important, a balanced diet is still the goal. Low-potassium fruits (like berries, apples, and grapes), lean proteins, and grains can round out your meals. Incorporating a variety of the lowest-potassium vegetables ensures you receive essential vitamins and fiber without compromising dietary restrictions. Always consult with a healthcare provider or a registered dietitian to create a personalized meal plan that meets your specific health needs.

Conclusion

While a definitive single vegetable may vary depending on the specific serving and preparation, raw radishes and iceberg lettuce are consistently among the lowest in potassium, with cucumbers also being a strong contender. By making informed choices and utilizing proper cooking techniques like leaching, individuals on a low-potassium diet can enjoy a wide array of nutritious vegetables. For comprehensive guidance on managing a low-potassium diet, the National Kidney Foundation is an excellent resource.

Frequently Asked Questions

Yes, raw spinach is considered a low-potassium vegetable, with about 156 mg per half-cup. However, cooked spinach is high in potassium, so it is best to consume it raw or in very limited quantities if following a restricted diet.

Yes, cooking methods like boiling can reduce the potassium content of vegetables. Water-soluble minerals like potassium leach out into the cooking water, especially when the vegetable is cut into smaller pieces.

While potatoes are naturally high in potassium, they can be included in a restricted diet by using the leaching method. Peeling, dicing, and soaking potatoes in a large volume of water before cooking can significantly reduce their potassium content.

The lowest-potassium option for a salad base is iceberg lettuce due to its high water content and low mineral levels. Mixed green salads using a combination of low-potassium vegetables like cucumbers and radishes also work well.

The canning liquid in canned vegetables can contain excess minerals. To reduce potassium, drain and rinse the canned vegetables before eating or cooking.

It is best to limit or avoid vegetables known for high potassium content, such as baked potatoes, sweet potatoes, cooked spinach, and tomato juice. These foods can significantly impact your daily potassium intake.

A low-potassium diet is often prescribed for individuals with chronic kidney disease (CKD) or those on certain medications that can cause potassium to build up in the blood. Healthy kidneys typically filter out excess potassium, but this function is compromised in CKD.