C-reactive protein (CRP) is a protein produced by the liver in response to a broad range of causes, such as infection from hepatitis or cancer, and is a general marker of inflammation.

High CRP levels are often seen in acute inflammation and have been correlated with high cardiovascular disease risk, while smaller elevations are often indicative of chronic inflammation and chronic diseases, such as metabolic syndrome and diabetes.

Low-level inflammation can go unnoticed and can be very damaging long-term, leading to the development of many chronic diseases. Sometimes an individual will experience symptoms such as pain or fatigue due to such inflammation, but often there will be no symptoms until disease occurs. An increase in CRP levels can indicate a hidden disease that has not yet been diagnosed; in fact, some research suggests that the level of CRP can predict heart disease even ten years before diagnosis.

The CRP blood spot test offered by GrassrootsHealth uses a high sensitivity assay, hs-CRP where “hs” means high sensitivity, to detect small elevations in CRP.

How to read your results

You can access your hs-CRP results by clicking on the “hs-CRP” tab at the top of your “my Test Results” page.

The results will look as follows, with your current value indicated in the graph on the left, and all results plotted by time in the chart on the right.

NOTE: The image below is for demonstration only and does not reflect your personal results.

Below this you will find a table of your latest and past hs-CRP results. The latest results will be at the top.

What hs-CRP level do you want to aim for?

A normal hs-CRP level is below 3.0 mg/L. A level between 3.1-10 mg/L is considered elevated, usually seen in chronic inflammation such as that involved with cardiovascular disease risk. An hs-CRP level above 10 mg/ L is very high, more likely indicating an acute inflammatory event due to infection or trauma.

What does a high hs-CRP level mean, and when might it be cause for concern?

An hs-CRP level at the very high range (above 10 mg/L) is most often seen after acute injury, infection, or surgery (including dental work). Known as an ‘acute-phase’ marker of inflammation, CRP is produced in response to inflammation and tissue damage, and levels can increase drastically within hours following the infection or injury.

High levels can also be seen during a flare-up of a known chronic condition (e.g. sickle cell disease, thalassemia, diabetes, cancer, heart disease, or rheumatology/autoimmune disease), or can be associated with smoking, overweight/obesity, high triglycerides, insulin resistance, diabetes, and renal dysfunction.

An hs-CRP level that is consistently in the elevated range (between 3.1-10 mg/L) may be due to an underlying chronic disease, and re-testing is highly recommended. If your hsCRP result is consistently high without a known cause or reason, it is recommended that you discuss your results with your health care provider, who may recommend additional testing.

What types of diseases are associated with chronic, low-level inflammation?

Chronic, low-level inflammation has been linked to a number of chronic diseases, ranging from cardiovascular disease to diabetes, cancer, dementia, autoimmune disease, mental health disorders, and more. The higher the inflammation levels over the long-term, the higher the risk of developing these diseases.

What can you do if your hs-CRP result is too high?

In some cases, such as following an injury or recovering from an illness or infection, a high hs-CRP level will decrease on its own over time. Lowering CRP levels in the long term can be addressed with specific lifestyle changes such as increasing exercise, losing weight, and quitting smoking. Doing so can also help decrease the risk of many chronic diseases associated with chronic inflammation and higher CRP levels.

The following links offer more specific information and research on reducing hs-CRP levels and inflammation.

CRP, an Indicator of Current and Future Health, is Greatly Influenced by Several Nutrients
Studies have associated CRP levels with the intake and status of specific nutrients, including vitamin D, omega-3s, and magnesium. This post reviews several such studies and also discusses specific disease associated with high CRP levels and chronic inflammation.

Reducing Inflammation through Diet
Several different nutrients and compounds, such as polyphenols, omega-3 fatty acids, and antioxidant vitamins, have been shown to have anti-inflammatory effects, while others, such as some saturated fats, trans-fatty acids, and sugars, have pro-inflammatory effects. This post reviews specific foods and diets that have been associated with lowering inflammation and CRP levels.

DHA Supplementation Decreases C-Reactive Protein and other Markers of Inflammation
DHA supplementation may improve heart health in several ways including a significant anti-inflammatory effect. This post summarizes a study on the effects of supplementation with an omega-3 fatty acid, docosahexaenoic acid (DHA), on inflammation in men who were at high risk of developing heart disease. Of note, the reduction in CRP concentrations found in this study is comparable to the 15-25% reduction in CRP caused by statins (the frontline pharmaceuticals used to prevent heart attacks and stroke) without any of the adverse effects.

Vitamin D Shown to Improve Markers of Liver and Cardiovascular Health
This post reviews a study that evaluated whether improving vitamin D serum levels had a beneficial effect on liver function, as well as markers of inflammation (including CRP), kidney function, and cardiovascular health. The study found a 41% decrease in CRP levels among women who were treated with vitamin D for two months.

Is there a relationship between vitamin D status and hs-CRP level?

A study by Yang et al. highlighted the relationship between CRP and vitamin D levels in 24 different diseases. Data from 9,809 adult subjects who had participated in the U.S. National Health and Nutrition Examination Survey (NHANES) between in 2007 and 2010 was collected and analyzed. Upon analysis, they discovered a negative association between CRP and vitamin D levels overall, with higher levels of vitamin D associated with lower levels of CRP. The strength of associations varied among diseases. The following were seen:

• CRP and vitamin D associations were generally linear among respiratory, gastrointestinal, and mental diseases, meaning that as vitamin D levels increased, there was a steady and continuous decrease in CRP levels- CRP and vitamin D associations were stronger in mental diseases

• CRP and vitamin D showed a non-linear association among metabolic diseases such as diabetes and cancer, meaning the effect of vitamin D on CRP levels was greater at lower levels but slowed at higher levels of vitamin D, with an eventual plateau
  
• Cancer had a higher cut-off value of vitamin D than other diseases, meaning that after other diseases reached a plateau with vitamin D cancer still showed a reduced risk from higher levels
  CRP and vitamin D also demonstrated a negative relationship in cardiovascular and cerebrovascular diseases
  
• The relationship between CRP and vitamin D levels were statistically significant for the majority of diseases; the authors concluded that nonsignificant associations may have been due to too few people with those diseases

The table below further outlines the association between CRP and Vitamin D among the 24 different diseases. Diseases in bold are those that had a statistically significant relationship between vitamin D and CRP levels.

What other nutrients could affect hs-CRP levels?

Studies have shown that, in addition to getting enough vitamin D, getting enough

• omega-3 fatty acids

• magnesium and zinc

• and probiotics

have also been associated with lower CRP levels.

What are the hs-CRP levels of other participants?

Among the 366 participants who had tested their hs-CRP levels at the time of analysis, the average level was 0.4 mg/L. Almost three fourths (74%) of participants had hs-CRP levels <1.0 mg/L (low risk), 19% had levels between 1.0 and 3.0 mg/L (average risk), and 8% had levels between 3.1 and 10.0 mg/L (increased risk).

Additionally, among those who completed two or more tests, 40% of those with average risk (1.0 to 3.0 mg/L) and 86% of those with increased risk (3.1 to 10.0 mg/L) lowered their CRP levels after their first test.

Questions?

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