C-reactive protein (CRP) is a substance produced by the liver that increases in the presence of inflammation in the body. An elevated C-reactive protein level is identified with blood tests and is considered a non-specific “marker” for disease. It can signal flare-ups of inflammatory diseases such as rheumatoid arthritis, lupus, and vasculitis. Data from a large number of studies also suggest that over time, chronic low-level internal inflammation can lead to many serious, age-related diseases including heart disease, some forms of cancer, and neurodegenerative conditions such as Alzheimer’s and Parkinson’s disease.
What are the symptoms of elevated C-reactive protein?
Elevated CRP levels have no outward, noticeable symptoms.
What are the causes of elevated C-reactive protein?
Elevated CRP can signal many different conditions, including cancer, cardiovascular disease, infection, and autoimmune conditions such as rheumatoid arthritis, lupus, and inflammatory bowel disease. The chronic inflammation behind an elevated CRP level may also be influenced by genetics, a sedentary lifestyle, too much stress, and exposure to environmental toxins such as secondhand tobacco smoke. Diet has a huge impact, particularly one that contains a lot of refined, processed and manufactured foods.
How is elevated C-reactive protein diagnosed?
C-reactive protein levels are measured via a blood test. There are two tests for elevated CRP. One can show a non-specific elevation of CRP that occurs with general inflammatory changes in the body. The other test, hs-CRP, is a measure of inflammation in blood vessels. This is the test needed to help establish heart disease risk.
In evaluating cardiac risk, physicians look at a very narrow range of C-reactive protein levels, from zero to 3.0 and above. This requires a special test called high-sensitivity C-reactive protein (hs-CRP), which may be able to reveal inflammation at the micro-vascular level. If this test shows that CRP is less than 1.0 mg per liter of blood, the risk of heart disease is considered low; if it is between 1.0 and 3.0, the risk is average; and if it is above 3.0, the risk is deemed high.
The American Heart Association (AHA) recommends hs-CRP testing for evaluating patients with an intermediate risk of heart disease, such as a 10-20 percent risk of having a heart attack in the next 10 years. However, the AHA doesn’t advise routine hs-CRP testing in patients who aren’t at high risk for heart disease. But some physicians, including Dr. Weil, believe that all adults should have an hs-CRP test whenever their cholesterol is tested.
People who have certain arthritic or autoimmune conditions tend to have elevated C-reactive protein levels because inflammation underlies these disorders. Arthritis may push test results far beyond the range used to assess heart disease risk. In most of these people, CRP levels tend to be above 100 mg/L. The hs-CRP test isn’t used for patients with rheumatoid arthritis, inflammatory bowel disease, or other autoimmune conditions. Instead, doctors evaluate inflammation with a test that measures levels in excess of 10 mg/L. When checking CRP for arthritic and autoimmune disorders, a level of 10 mg/L or lower is considered “normal.”
Because an hs-CRP test isn’t useful to assess cardiovascular risk among people with inflammatory diseases, these patients have to rely on such well-recognized risk factors as high blood pressure or high cholesterol, whether or not they smoke, their weight, and their risk of diabetes. In addition to such standard measures for reducing the risk of cardiovascular disease as exercise, keeping weight under control, practicing stress reduction techniques, and getting adequate sleep, Dr. Weil recommends that people with these disorders make an effort to reduce inflammation and their risk of heart disease by following an anti-inflammatory diet.
What is the conventional treatment of elevated C-reactive protein?
Conventional physicians may prescribe the same (statin) drugs used to lower LDL cholesterol to also lower levels of CRP. In addition, they will typically recommend exercise and weight loss where appropriate, since both can help lower CRP levels. In general, conventional physicians recommend the same lifestyle changes shown to reduce heart disease – diet, exercise, not smoking, drinking less alcohol, following a heart-healthy diet – to lower elevated C-reactive protein levels.
What therapies does Dr. Weil recommend for elevated C-reactive protein?
Dr. Weil recommends an anti-inflammatory diet that includes two to three servings of fish such as salmon or sardines per week. If you don’t eat fish, he suggests taking fish oil supplements. He also recommends taking anti-inflammatory herbs including ginger and turmeric and following your doctor’s recommendations for heart health. That means quitting smoking, watching your diet (particularly avoid foods that predominantly consist of flour and/or sugar), and getting regular exercise: research indicates that as fitness levels decline, C-reactive protein levels go up.
Reviewed by Benjamin S. Gonzalez, M.D., May, 2016.