Healthy number: Lower than 1.0 mg/L.
The amount of C-reactive protein (CRP) found in the blood, measured in milligrams per liter (mg/L), is a marker of chronic, low-grade inflammation that has been linked to heart disease, stroke, diabetes, and some forms of cancer.
Have yours checked: When you don’t know your risk for heart disease. CRP levels aren’t routinely measured, “but it’s useful information, especially if you don’t know your risk or family history for heart disease,” says David Katz, M.D., director of the Yale University School of Medicine Prevention Research Center. “Doctors typically test CRP levels if they’re undecided about how aggressively to treat someone with borderline-high cholesterol or symptoms of angina but no other risk factors.” They may also order the test if a patient lacks these risk factors but has a strong family history of heart disease. In such cases, a high CRP level may lead a doctor to prescribe drug therapy, such as statins, earlier, or to suggest that the patient make more aggressive lifestyle changes (a healthy diet, more exercise) sooner rather than later. If you have high CRP levels, your doctor should recommend lifestyle changes and eating foods rich in omega-3 fatty acids (such as salmon, walnuts, canola oil, and ground flaxseed) to help reduce inflammation in the body.