Cholesterol and kidney disease

Explore the connection between high cholesterol and kidney disease by learning about the different types and causes of high cholesterol as well as ways to prevent and treat it.

What is cholesterol? 

Cholesterol is a waxy, fat-like substance in your blood. Your body can make cholesterol or get it from eating certain foods, such as meat. Your body needs a very small amount of cholesterol to build healthy cells. However, too much cholesterol can cause health problems, such as kidney disease.

There are two main types of cholesterol:

  • LDL (low-density lipoprotein) cholesterol: This is often called "bad" cholesterol because high levels can build up in your arteries causing them to narrow. When your arteries narrow, it is harder for your blood to flow and can lead to blockages. Arteries are tubes that your heart pumps blood through. Foods that raise LDL cholesterol are:
  • Saturated fats, which are in red meat, full-fat dairy products, butter and certain oils like coconut and palm oil
  • HDL (high-density lipoprotein) cholesterol: This is often called "good" cholesterol because it helps remove LDL "bad" cholesterol from your blood. 

Cholesterol is important for keeping your body healthy because it helps with:

  • Cell structure: cholesterol is like the building blocks for your cells, making them strong and flexible.
  • Making hormones: your body uses cholesterol to make hormones like the ones that help you grow, feel emotions, and even handle stress.
  • Getting vitamin D: cholesterol helps your body make vitamin D when you're out in the sun. Vitamin D is important for keeping your bones strong and helping your body absorb calcium from food.

What causes high cholesterol? 

There are many causes of high cholesterol, such as:  

  • Eating a lot of foods high in LDL "bad" fats such as red meat, processed foods and baked goods  
  • Not being active enough, which can raise your LDL cholesterol and lower your HDL "good" cholesterol
  • Smoking and drinking alcohol, which lowers your HDL cholesterol and can harm your heart
  • Genes inherited from your parents, because high cholesterol can run in families. Genes are a part of your cells that contain DNA and affect how your body processes fats and cholesterol.  

Age and gender also play a role. Women often have lower cholesterol levels than men until menopause when their levels may rise to a similar range.

Diabetes is another factor. If you have diabetes, there is an increased risk of having higher levels of LDL cholesterol and lower levels of HDL cholesterol.  

How does high cholesterol cause kidney disease? 

High cholesterol can cause kidney disease over time. Here is how the process works: 

  1. High cholesterol damages arteries that send blood to your kidneys, which makes your kidneys act as if you are dehydrated (do not have enough water in your body). 
  2. When this happens, your kidneys tell your body to hold on to extra salt and fluid. 
  3. This causes your blood to fill with this extra salt and fluid, which raises your blood pressure.  
  4. Having high blood pressure over a long period of time can lead to kidney failure. 

How will I know if I have high cholesterol? 

High cholesterol usually does not have clear signs or symptoms, so you will need to get tested. A blood test is the best way to know your cholesterol levels. 

Experts recommend people with chronic kidney disease (CKD) get their cholesterol tested at least once a year, but some doctors may suggest testing more often. Ask your doctor how often you should get tested based on your health history.  

Healthy cholesterol levels are: 

  • Total cholesterol: Aim for less than 200 milligrams per deciliter (mg/dL) 
  • LDL "bad" cholesterol: Lower is better, aim for less than 100 mg/dL 
  • HDL "good" cholesterol: Higher is better, aim for 40 mg/dL or more

What can I do to prevent or manage high cholesterol?  

To prevent high cholesterol, doctors recommend the same advice as for treating high cholesterol. To treat high cholesterol, doctors recommend: 

  • Be mindful about what you eat. Your body already makes the cholesterol it needs, so you do not have to get it from food.  
    • Limit foods that are high in saturated fat. These include red and processed meats, cheese, butter and certain oils like palm oil and coconut oil. 
    • Choose foods low in saturated fat such as lean meats, seafood, low-fat dairy products, whole grains, fruits and vegetables. 
    • Eat fiber and unsaturated fats like oatmeal, beans, avocados, olive oil and nuts.  
    • Find more information on following a kidney-friendly eating plan on Kidney Kitchen.  
  • Be active for at least 30 minutes a day most days of the week. Move your body by walking, swimming or dancing. Daily exercise: 
    • Helps get your blood flowing, which can lower the amount of LDL "bad" cholesterol in your arteries 
    • Can raise your level of HDL "good" cholesterol  
    • Helps you keep a healthy weight  
  • Do not smoke or use tobacco products. And try to quit if you do use tobacco. Smoking cigarettes can lower your levels of HDL cholesterol and damage arteries, which makes it easier for LDL cholesterol to stick to your arteries and cause blockages. 
  • Limit the amount of alcohol you drink. Talk to your doctor about a healthy amount for you based on your age and health history. 
  • Some people may be prescribed medicines like statins, which can help lower LDL cholesterol in your blood, and slow down cholesterol build-up in arteries. Statins have benefits beyond lowering LDL, patients with lower LDL can find statins beneficial as well.