Milk and Phosphorus
Chronic Kidney Disease (CKD) patients, and especially those on dialysis - referred to as End Stage Renal Disease (ESRD) - are told to limit the intake of milk and dairy products.
The reason for this is the nutritional contents of milk. One cup of whole milk (8 oz.) contains about 10% of the recommended daily intake (RDI - I know, so many initials to remember), 22% of phosphorus, and 23% of saturated fat. That’s very high for a glass of milk. Especially because you will find phosphorus in nearly all of the foods we eat. So getting almost one quarter of your RDI in a small glass of milk could push you over the recommended limit.
So why is this a problem? People with functioning kidneys can process out excess amounts of nutrients through urination. Have you ever heard the joke about certain vitamins and supplements? It just creates expensive urine.
That’s right, if you ingest more nutrients that your body needs, you just pee it out. That’s not to say that there isn’t value to those supplements, it means you should listen to your doctor or dietician about what your body is deficient in, and the appropriate amounts needed to supplement.
For those of us with depleted kidney function, our bodies don’t process out the extra minerals like phosphorus. The result is that those minerals stay in our blood and can do damage to our bodies. The National Kidney Foundation (NKF) website tells us “High phosphorus levels will end up pulling calcium from our bones, making them weak.” This can lead to dangerous calcium deposits in blood vessels and other organs. None of that is good.
Controlling the phosphorus in CKD patients is left up to diet and binders in pill form, that don’t allow for absorption of all the phosphorus into our system. Of course they also have some unpleasant side effects. and some of those pills are hard to swallow, both figuratively and literally - they are fairly large.
So that’s why high phosphorus is a problem, especially in CDK patients.
With all this information it’s easy to see why nutritionists and doctors tell their patients to limit their intake.
But there are some positive sides to these products, especially if you have ESRD and are on dialysis. They have lot’s of protein and other nutrients which we need like vitamin A and B12.
To begin with let’s discuss the contents of milk. One of the big concerns is the fat (we will discuss that issue later and in another section). Let’s look at exactly what we are drinking:
Milk Product Fat Content
Reduced Fat 2%
Low Fat 1%
Milk comes out of the cow as whole milk. Making the lower fat products is done using a “separator”, spinning the milk fat out of the whole milk to the desired level of fat content. But all of these lower fat products contain higher amounts of Phosphorus and Potassium than most nutritionists like to see in a serving for dialysis or CKD patient. In fact, lowering the fat content in milk slightly increases the amount of phosphorus and potassium.
“Wait a minute. Higher you say?” Yes. Not only do I say it, but so do all of the nutrition data experts, and scientists. The reason for this anomaly is that by removing the fat you are increasing the concentration of the other parts that make up milk, and thats where most of the Phosphorus and Potassium live.
Milk is made up of about 87% water, 3.5% proteins, 3.7% fat, 4.9% lactose, and .07 % minerals (This is by weight, hence the slight difference in fat by volume.) Separating the milk fat from the rest of the milk increases the concentration of the products left in the lower fat milk. Since we are removing a lower concentration part from the higher concentration part, what’s left will have more of those nutrients by volume.
In addition, by spinning out the fat molecules, you also remove some of the fat soluble nutrients that milk provides. After the spinning process, Vitamin A and D are usually adding back into the product, making it fortified.
Speaking of labeling on Milk (weren’t we?), pasteurization is a heating and holding process that destroys organisms that can cause disease, without hurting the nutritional content of the milk or other product. Thanks Louis!
Next the milk is homogenized. Why? I’ll tell you why. Remember the old way of making cream - letting the milk sit for a short while and having all the fat rise to top and skimming it off? Of course you do. Well, homogenization is another spinning process that standardizes all the fat molecules to a small size, thus making it more difficult to separate on the stores refrigerator shelf, or anywhere else for that matter.
Why is all this important to CDK patients? Understanding. The more we understand about the food we eat the more we will be able to evaluate all foods to help us with a healthier diet for our disease.
So what about some of those other milk based products? For instance, the cream that in removed from the milk? Good question and I’m glad you asked.
Let’s look at the phosphorus and potassium content in some of these products in one cup of each product. The RDI is in parenthesis:
Product Phosphorus Potassium Calcium
Whole Milk 222 mg (23%) 348 mg (10) 276 mg(28%)
2% milk 245 mg (25%) 397 mg (11%) 314 mg (31%)
1% milk 245 mg (25%) 397 mg (11%) 314 mg (31%)
Skim 276 mg (28%) 448 mg (13%) 352 mg (35%)
1/2 and 1/2 230 mg (23%) 315 mg (9%) 245 mg (25%)
Heavy Cr. 148 mg (15%) 178 mg (5%) 155 mg (15%)
Light Cr. 146 mg (15%) 232 mg (7%) 165 mg (16%)
As you can see, going from whole milk at 3.25% milk fat to skim increases all three minerals in each product. Using heavy cream drops all three of these in half, and diluting the heavy cream to decrease the fat content, starts to bring in back up , but not to levels of of the other milk products.
This chart is a little deceiving. While it is very reasonable to drink or use 8 oz of whole milk or the lesser fat products, you would not be very likely to consume that much heavy cream in a serving. If you are someone who puts milk or cream in your coffee, you are likely to use more of the less fattened up product than with the higher fat products.
In a recipe I always use heavy cream instead of any other milk product. This may sound counterintuitive based on all the mental beatings we have been through concerning low fat diets, and low fat products. But as you see in the chart, it lowers some of the dangerous minerals in the diet of the CKD patient.
As for the fat content, there is plenty of new data from current and more professional studies that are telling us that fat is not the problem we have been led to believe it is. It does not increase the cause of heart disease. It does not increase your bad cholesterol enough to cause problems, unless you are genetically predisposed to high cholesterol.
In fact, it is not even the cause of obesity. The new studies are showing that sugar, more specifically processed sugars, are linked to obesity, high LDL cholesterol (the bad one), diabetes, and other related issues including heart disease. I will go into more detail about fats in another section on this site, but the basic principle in some studies is that when we reduce the good fats in our diet, we end up replacing the calories from those fats with something else. That something else is usually sugar, and more specifically processed sugar. This is where we find ourselves consuming products that cause the above mentioned problems.
This has led me to discount the large concerns about higher saturated fat products concerning my health and diet, for better control over proven risk factors for CKD patients, like phosphorus and potassium.
In essence, I use Heavy cream for my recipes and I avoid most low fat products. The extra fat in the heavy cream will make you fuller, faster. With the calories coming from foods that I know about, rather than snacks and foods I do not know about, I can help control the dangerous levels of phosphorus in my diet.
Links to recipes on this topic:
Pasta and Squash in a Cream Sauce
Here are some links to sources I have used for information above: