It’s In The Blood
When it comes to health, a wealth of information can be obtained from having blood work done on a regular basis. Blood is our most vital bodily fluid. It helps transport oxygen and nutrients to cells, while also transporting metabolic waste products away. A little over half our blood is plasma, which is mostly water along with protein, sugar, minerals, hormones, and carbon dioxide for removal. The rest of our blood consists of cells that are suspended in the plasma. There are red and white blood cells, with red blood cells being the most abundant. Red blood cells obtain their color from hemoglobin, which helps them transport oxygen. White blood cells help defend the body against foreign materials and diseases, and are part of the immune system. When looking at blood work, I am most interested in the HDL, LDL, Triglycerides, CRP, fasting blood sugar, and HbA1c. Let’s take a look at the meaning of each one of these bio-markers, and what we can do to improve them.
High total cholesterol used to be considered the most important bio marker for heart disease risk. Cholesterol plays a part in intracellular transport, cell signaling, nerve conduction, and helps maintain membranes. It’s also converted into bile in the liver and stored in the gallbladder. Bile helps aid in the absorption of fat, and fat soluble vitamins A,D,E, and K. It is also a precursor molecule for the synthesis of vitamin D, steroid hormones, and some research indicates that it may be an antioxidant. So as you can tell, even though cholesterol has been demonized in the past, it is actually a very important substance in the human body. A 1994 study out of the International Journal of Clinical and Laboratory Research showed that total cholesterol alone may be a misleading as a bio-marker for cardiovascular disease. The Copenhagen City Heart Study follow-up revealed that increasing cholesterol levels were not associated with total mortality but rising triglycerides levels were. Research published in the American Heart Journal in 2008 announced that 75% of the patients hospitalized for a heart attack in the study had cholesterol levels that were not considered high risk. From a number of past studies, it looks like total cholesterol is no longer a very useful number. Cholesterol is transported by lipoproteins which enable the transportation of fats and cholesterol in extracellular fluid and the blood. It’s important to look at two lipoproteins in particular, High Density (HDL) and Low Density (LDL) Lipoprotein. HDL is often called the “good cholesterol” because it is thought to remove fats and cholesterol from within cells and artery walls, transporting it back to the liver. I have heard it said that you can visualize HDL as tiny scrubbers within your circulation system. Research in the American Journal of Cardiology (AJC) acknowledged that low HDL levels were related to Coronary Heart Disease (CHD). LDL is often called the ‘bad cholesterol”. LDL also enables the transport of fats and cholesterol, just as HDL does, but they deposit this cargo into artery walls. This causes macrophages and white blood cells to accumulate, resulting in a chronic inflammatory response. This is known as atherosclerosis. A 15 year Chinese MultiProvincial Cohort Study uncovered that very low density lipoprotein (VLDL) was found to be significantly associated with CHD. The risk was increased when elevated LDL and/or other CHD risk factors were present. VLDL is made up of a majority of triglycerides. As the triglycerides are removed for storage or energy production, a majority of cholesterol is left, and VLDL is converted into LDL. Interestingly enough, a study out of Japan showed that serum triglyceride levels were comparable to LDL as a CHD predictor in patients with type 2 diabetes. That leads us into the next bio marker of interest which has already been mentioned several times in this post, triglycerides.
- Men: above 40 mg/dl
- Women: above 50 mg/dl
- Heart Disease Protection: 60 mg/dl or greater
- Best: Less than 100 mg/dl
- Near Best: 100-129 mg/dl
- Borderline High: 130-159 mg/dl
- High: 160-189 mg/dl
- Very High: 190 mg/dl or higher
- Normal: 2 to 30 mg/dl
Triglycerides may be one of the most important CHD risk factors to take note of. Triglycerides are involved in metabolism as energy sources and they are considered a type of fat found in the blood. Triglyceride levels appear to rise when there is excess glucose in the liver. The excess sugar in the liver that can not be moved to glycogen or metabolized by mitochondria for energy, is converted to triglycerides. High levels can raise your risk of CHD and could be a sign of metabolic disease. A 2010 study in the AJC that I mentioned earlier affirmed that when LDL is controlled, high triglycerides combined with low HDL contribute strongly and synergistically to CHD. Also, high triglycerides and triglyceride to HDL ratio had a high probability of determining insulin resistance as found by Esteghamati, MD and colleagues. If you eat a high carbohydrate diet and or/ a lot of sugary foods, there is a good chance you will have elevated triglycerides.
- Normal: less than 150 mg/dl
- Borderline High: 150-199 mg/dl
- High: 200-499 mg/dl
- Very High: 500 mg/dl and above
C-Reactive Protein (CRP) is a protein found in the blood that rises when inflammation is present. High CRP levels can be caused by diseases and infection. CRP is believed to help bind to foreign and damaged cells, assisting macrophages in phagocytosis, and as part of the early defense system of the immune system. A study out of the Atherosclerosis journal proclaimed that high sensitive CRP was a predictor of strokes in middle aged Japanese men and women. More research out of the American Heart Association indicated that modest elevations in CRP significantly predict coronary events in initially healthy middle aged men.
C-Reactive Protein Levels
- Low Risk of CHD: Less than 1.0 mg/L
- Average: 1.0 to 3.0 mg/L
- High Risk: Greater than 3.0 mg/L
Fasting blood glucose is the amount of sugar present in the blood, usually after a 12 hour fast. Glucose is a source of energy for the cells, available for cell absorption with the help of insulin. Chronically high blood sugar can cause heart disease, organ and nerve damage. It also leads to type 2 diabetes. A study out of the American Diabetes Association showed that lowering blood glucose can reduce mortality. HbA1c is a form of hemoglobin that can be used to infer the average plasma glucose concentration over the previous 2 to 3 months. Research out of the European Journal of Preventive Cardiology brought to light that high levels of HbA1c are associated with future risk of non-fatal CVD in Caucasian men and women ages 50 to 75 years old. And Finally, subjects with high-normal levels of HbA1c have a strong risk of developing diabetes according to information in the Journal of Diabetes.
Fasting Blood Glucose Levels
- Normal: 70 to 100 mg/dL
- Pre-diabetes: 100 to 125 mg/dL
- Diabetes: 126 mg/dL or higher
- Normal: Less than 5.7%
- Pre-diabetes: 5.7% to 6.4%
- Diabetes: 6.5% or Higher
If we find that these numbers are less than ideal in our own blood, then what can we do about it? It really comes down to nutrition and exercise. From the research I have seen, the best nutrition strategy appears to be a reduction in carbohydrate intake. Most people would think a reduction in fat would be the optimal strategy, but that is the strategy that has been used in the United States for several decades with heart disease, type 2 diabetes, and obesity all becoming more prevalent. A study in the American Journal of Clinical Nutrition looked at saturated fat, carbohydrate, and cardiovascular disease. They concluded that a reduction in refined carbohydrate was the best option for reducing Cardiovascular Disease (CVD) risk. Research in the Metabolism Journal informed that a high fat low carbohydrate diet had greater improvements in blood lipids (lower triglycerides and higher HDL) and reduction in systemic inflammation (lower CRP) than a low fat high carbohydrate diet with similar reductions in body weight and composition. Another study in Nutrition and Metabolism advised obese patients with type 2 diabetes to follow a 20% carbohydrate diet with some caloric restriction for long term effects on body weight and glycemic control. And finally, the New England Journal of Medicine contained research that showed that Mediterranean and low carb diets were effective alternatives to a low fat diet. The most favorable effects on lipids were with the low carb diet and the Mediterranean diet was best for glycemic control. Exercise can be just as important. High intensity endurance training was found to be more effective than moderate intensity for lowering post meal triglyceride elevation. Another study showed that 9 months of endurance training helped decrease CRP and had a systemic anti-inflammatory effect. Resistance training resulted in a greater decrease of CRP concentration in comparison to aerobic training group as written in the journal of Medicine and Science in Sport and Exercise. And in conclusion, a study in JAMA verified that a structured exercise program that combined aerobic and resistance training provided the best glycemic control and reduced HbA1c levels in patients with type 2 diabetes. Probably the best approach is a balanced one for exercise, focusing on both strength and conditioning. As we can see, nutrition and exercise can have positive effects on all these important bio markers.
Blood work can give us a window into how the body is reacting to our current nutrition and exercise plans. If you have had blood work recently and have a copy of it, you can see how it compares to levels mentioned in this post. If you haven’t had blood work done in a long time, you may want to ask your physician if you can get it done and make sure to include the bio markers mentioned. I wish I could have all my clients get blood work done, and on a regular basis to track how the body is reacting to any changes in diet and workouts. Unfortunately, it can be expensive to have your blood tested, but I think it is worth a lot to know the vital information hidden in it. I have heard there are now companies online that allow a person to order their own blood test and have their blood drawn at a participating laboratory. It could be something to look into if you don’t currently have a physician. We are often focused on the external changes as we make a transition to a healthier lifestyle, but don’t underestimate the wealth of knowledge to be found in the blood.