Lupus is an autoimmune disease that causes the immune system to mistakenly attack healthy tissues throughout the body. When this attack targets the kidneys, it leads to a type of chronic kidney disease called lupus nephritis.

The kidneys act as the body’s filtration system. They regulate electrolytes, remove waste, and maintain protein balance in the blood. Lupus nephritis results from immune system dysfunction. Making certain dietary changes can support kidney function and help manage complications.

The specific dietary guidelines you’ll need to follow depend on the severity of your kidney disease. Learning which foods to include and which to limit may seem overwhelming. With the support of your nephrologist, a registered dietitian nutritionist, or another specialist in kidney health, you can build a diet that meets your needs.

Here are some food basics to get you started.

1. Foods With Healthy Fats

Heart-healthy unsaturated fats are essential for a healthy diet. Specifically, omega-3 fatty acids help protect against heart disease, which is a concern for those with lupus.

Omega-3s can be found in plant-based sources, such as nuts and seeds. Animal sources include sardines, salmon, mackerel, and other fatty fish. You can easily add flaxseed to granola, cereal, yogurt, baked goods, or smoothies. The fiber in flaxseed can be hard to digest, so it’s best to grind it to release the full benefits.

Kidney-friendly combinations like these can boost your intake of healthy fats:

• Canned or smoked salmon in place of tuna salad or cold cuts
• Chia seeds mixed into yogurt or oatmeal
• Guacamole on crackers or sandwiches
• Hemp hearts on salads
• Olive oil and vinegar as salad dressing
• Walnuts in baked goods

2. Low-Potassium Fruits and Vegetables

Fruits and vegetables are essential for good health. Many fruits and vegetables contain potassium, a nutrient that helps keep cell fluid at the right level. However, too much potassium can be dangerous if you have kidney damage.

Choosing lower-potassium fruits and vegetables will provide vitamins, minerals, antioxidants, and dietary fiber while protecting your kidneys. Be sure to pay attention to serving sizes. Big portions can turn a low-potassium food into a large serving of potassium.

Pay attention to serving sizes. Big portions can turn a low-potassium food into a large serving of potassium.

Lower-potassium fruits and fruit-based foods — containing less than 150 milligrams of potassium per half cup — include:

• Applesauce
• Blueberries
• Cranberries
• Eggplant
• Pineapple
• Watermelon

Vegetables that aren’t too high in potassium include:

• Cucumbers
• Endive
• Onions
• Raw cabbage

Talk to your doctor about how much you need to limit your consumption of high-potassium fruits and vegetables (more than 250 milligrams per half cup). High-potassium fruits and vegetables include:

• Avocados
• Bananas
• Cantaloupe
• Dates
• Nectarines
• Oranges
• Prunes
• Beets and beet greens
• Brussels sprouts
• Potatoes
• Spinach
• Sweet potatoes

Cooked vegetables and fruit juices are more concentrated in potassium than fresh produce. For instance, a few slices of fresh tomatoes have much less potassium than canned tomatoes or tomato sauce. Ask your renal dietitian or healthcare team about cooking methods, such as boiling veggies and discarding the cooking water, to remove some potassium.

Spacing smaller portions throughout the day will give your kidneys more time to process potassium from food. This may help avoid spikes in potassium levels.

Healthy fat sources such as avocados and nuts are high in potassium. Ask your doctor about your specific restrictions to determine the right serving sizes for you.

3. Low-Sodium Foods

Sodium (salt) can cause high blood pressure and put added strain on your kidneys. Moderating the amount of sodium you consume is one of the most important dietary changes to protect kidney function.

Here are some ways to cut back on sodium:

• Avoid pickled foods — Pickles, olives, and other preserved foods are typically very high in sodium.
• Cook fresh meats or choose plant-based proteins — Cold cuts, hot dogs, sausage, bacon, and jerky tend to be high in salt that’s added during processing.
• Experiment with salt-free seasonings — Fresh herbs, peppers, lemon juice, onion, or vinegar can enhance flavor and contain little or no sodium.
• Read food labels — When purchasing condiments, frozen meals, or snack foods, always check the label to compare how much sodium is in different brands.

It’s also important to watch out for canned items. Rinsing canned foods with water will help cut down on the sodium content. You can also look for sodium-free canned goods, such as beans or soups. Frozen vegetables are a sodium-free alternative to some canned vegetables.

Restaurant meals and processed foods usually have more sodium than you’d add when cooking for yourself. Check menus ahead of time to scope out low-sodium options, or ask your server if your food can be prepared with minimal salt.

Restaurant meals may have high sodium levels, so check menus ahead of time to scope out low-sodium options.

4. Plant-Based Protein

Your doctor may advise you to cut back on protein from red meat, chicken, fish, and dairy products to minimize strain on your kidneys. Cow’s milk and processed meats, such as deli ham and turkey, bacon, sausage, and hot dogs, are also high in phosphorus, which can put strain on your kidneys. High phosphorus levels can also weaken bones and cause high blood pressure. However, depending on the status of your kidney function, you may not need to cut out meat, fish, and dairy foods completely.

Plant-based protein generally has less protein and can help you get the nutrients you need while protecting your kidneys. Here are some plant-based proteins and dairy alternatives you can add to your diet:

• Tofu
• Nuts and seeds
• Beans
• Plant-based milks such as soy, almond, or oat milk

Some plant-based milks contain added phosphorus. You can avoid this by not buying products with “phos-” in the ingredients list. It’s also good to be mindful about the phosphorus and potassium content of nuts and seeds when planning your portions.

5. Sparkling Water and Unsweetened Iced Tea

If you’re living with lupus, it may be a good idea to avoid sugary beverages. Sugar may worsen inflammation and raise cardiometabolic risks. Limiting added sugars supports heart and kidney health. Sugary beverages such as soda and fruit juice can also lead to unwanted weight gain.

Dark sodas also contain high levels of phosphorus, which is hard on the kidneys. Fruit juice may sound healthy but is high in sugar because it concentrates the natural sugars in a lot of fruit to make a drink.

Healthier alternatives include sparkling water and unsweetened iced tea. Coffee and sugar-free clear sodas may also be better options. But you should always scan the label for phosphorus additives first.

Restricting Fluid

Normally, drinking plenty of water is helpful for the kidneys. However, if you have lupus nephritis, your body may take longer to filter out water. If your doctor has recommended that you restrict fluids, you can manage dry mouth by chewing gum, sucking on hard candy, or rinsing your mouth with water.

Medications and Supplements To Manage Kidney Problems

If you have kidney issues, your doctor might recommend phosphorus or potassium binders. These medications help reduce the load of phosphorus or potassium your body absorbs from food. You can ask your doctor if binders are a good option for you and how they might affect your diet when living with lupus nephritis.

Some people with lupus or kidney issues may require supplements to meet their nutritional needs. It’s important to take the right dose and form. Always check with your doctor before starting any dietary supplements, which can sometimes cause side effects or interfere with medications you may be taking. Echinacea, in particular, has been shown to increase inflammation in people with lupus.

Your doctor can check your levels of nutrients such as vitamin D or calcium and recommend supplements that are appropriate for you.

Talk to Your Doctor About Your Diet

If you’re confused about what to eat, don’t hesitate to reach out for help from your healthcare team. In addition to helping you understand lupus nephritis treatments, they can help you understand lifestyle behaviors that can support your health. Adjusting to a new way of eating takes time, so be patient with yourself as you focus on progress, not perfection.

Adjusting to a new way of eating takes time, so be patient with yourself as you focus on progress, not perfection.

Join the Conversation

On MyLupusTeam, people share their experiences with lupus, get advice, and find support from others who understand.

Do you follow any specific lupus-focused healthy eating plans? Let others know in the comments below.