Sodium and Kidney Health

What is sodium?

Sodium is a mineral found in foods. It is found naturally in foods like beets, celery and milk. But the added sodium is what you need to watch out for. It is added to foods primarily for flavor but can also act as a preservative and enhance color and texture. Sodium is also found in the body– it is required for normal muscle and nerve function and maintaining fluid balance. Although sodium serves important functions – too much is not a good thing!

The typically American diet provides about 3,400 milligrams (mg) of sodium a day, well above the recommended daily intake of 2,300 mg. You may be thinking “I never use a salt shaker so there is no way I’m getting too much sodium in my diet”. Well, on average, only 10% of sodium intake comes from added salt. The majority of sodium comes from packaged foods and restaurant/pre-prepared foods. Here are the top 6 foods American’s get their sodium from:

1. Breads and rolls

2. Pizza

3. Sandwiches

4. Cold cuts and cured meats

5. Soup

6. Burritos and tacos

Why should I worry about too much sodium?

Long term excess sodium intake has been shown to negatively impact blood vessels, heart, kidneys and studies show it is also linked to obesity.

Limiting sodium is an important part of a kidney healthy diet. Diet’s low in sodium help blood pressure medications work more effectively – that means less dose increases. Some people are even able to get off their blood pressure pills with proper diet modification. A low sodium diet also helps reduce proteinuria (presence of protein in the urine). Proteinuria is strongly associated with progression of kidney disease.

So how much sodium should I consume if I have kidney disease?

It’s recommended to take in less than 2,300 mg sodium per day. Many studies saw benefits to limiting sodium to about 2,000 mg per day. Restriction below 1,500 mg is not recommended and would be extremely difficult to achieve.

How can I cut down on my sodium intake?

Start out by learning how to read food labels properly. Food companies may put phases on the labels that state “reduced sodium”, “light in sodium” – don’t be fooled by their sneaky marketing strategies-that doesn’t mean the food is low in sodium or a healthy choice. Cola has "low sodium" listed on the food label and I would not call it a health food. Go to the back of the package and read the nutrition facts.

You can look at the total sodium two ways- the amount listed in milligrams, or the percent daily value. The percent daily value is calculated by dividing the total mg of sodium by the daily recommended intake, which is 2,300 mg and multiplying by 100.

Example for the label above: 430 mg of sodium / 2,300 mg sodium = 0.186 x 100 = 18.6% or 19%

In general, consider foods with 10% daily value of sodium to be good choices for sodium.

Another thing to check on the nutrition facts label is the serving size. This tells you the amount of food in the package that the nutrition facts are based on. If there are multiple servings in the package of food, make sure you take the into account if you end up eating the whole package of food!

Cooking at home is another great way to take control of your sodium intake. All restaurants add salt to their food. As mentioned above, salt provides flavor, and if a restaurant isn’t serving flavorful food they won’t be in business for long! Chain restaurants provide nutrition facts on their websites so you can find the sodium content by looking online but the actual sodium content will vary based on who does the cooking. It’s shocking to see sodium content of some of these foods, especially the seemingly healthy dishes. Here are some examples of sodium content of entrees from a popular chain restaurant:

Veggie burger: 2,440 mg sodium (exceeds the total recommended daily intake)

Grilled fish tacos: 1,730 mg sodium (75% of the recommended daily intake)

Almond-crusted Salmon Salad: 1,180 mg (51% of the recommended daily intake)

By cooking more at home, you are in charge of the quality of your ingredients and how much sodium ends up of your plate. If you cook with fresh ingredients – think raw produce, grains such as rice, quinoa, legumes, lentils - it’s okay to add a pinch of salt (which equals ~300 mg sodium) – it still won’t add up to as much sodium as a restaurant meal. There are also lots of frozen and canned beans and vegetables that do not have any added salt so these work too!

To sum things up….

Less than 2,300 mg sodium is recommended for people with kidney disease to help control blood pressure and reduce proteinuria. This will help preserve your kidney function. The salt shaker is typically not biggest culprit when it comes to excess sodium intake. Get in the habit of reading food labels. Compare different brands of products – bread for example – when grocery shopping and aim for products with 10% daily value of sodium or less. Restaurants can be enjoyed as a treat – we all deserve to have a night out to celebrate a birthday, anniversary of just take a break from cooking. Reducing the frequency of eating out is key. Both your wallet and kidneys will thank you!