What does your cholesterol tell you about your future health?
Cholesterol is a peculiar molecule. It is often called a lipid or a fat. However, the chemical term for a molecule such as cholesterol is alcohol, although it doesn’t behave like alcohol. Its numerous carbon and hydrogen atoms are put together in an intricate three-dimensional network, impossible to dissolve in water.
All living creatures use this lack of dissolvability cleverly, incorporating cholesterol into their cell walls to make cells waterproof. This means that cells of living creatures can regulate their internal environment undisturbed by changes in their surroundings, a mechanism vital for proper function. The fact that cells are waterproof is especially critical for the normal functioning of nerves and nerve cells. Thus, the highest concentration of cholesterol in the body is found in the brain and other parts of the nervous system where the most protection is needed. Cholesterol is essential to your health.
Because cholesterol is insoluble in water and thus also in blood, it is transported in our blood inside spherical particles composed of fats (lipids) and proteins, the so-called lipoproteins. Lipoproteins are easily dissolved in water because their outside is composed mainly of water-soluble proteins. The inside of the lipoproteins is composed of lipids, and here are room for water-insoluble molecules such as cholesterol. Like submarines, lipoproteins carry cholesterol from one place in the body to another. Think of it as your energy transport system.
The submarines, or lipoproteins, have various names according to their density. The best known are HDL (High Density Lipoprotein), and LDL (Low Density Lipoprotein). The main task of HDL is to carry cholesterol from the peripheral tissues, including the artery walls, to the liver. Here it is excreted with the bile or used for other purposes such as a starting point for the manufacture of important hormones. The LDL submarines mainly transport cholesterol in the opposite direction. They carry it from the liver, where most of our body’s cholesterol is produced, to the peripheral tissues, including the vascular walls. All cells can produce cholesterol, but if they need more than they are able to produce, they call for the LDL submarines, which then deliver cholesterol into the interior of the cells. Most of the cholesterol in the blood, between 60 and 80 per cent, is transported by LDL only 15-20 percent is transported by HDL . A small part of the circulating cholesterol is transported by other lipoproteins.
You may ask why a natural substance in our blood, with important biologic functions, is called ”bad” when it is transported from the liver to the peripheral tissues by LDL, but ”good” when it is transported the other way by HDL. The reason is that a number of follow-up studies have shown that a lower-than-normal level of HDL-cholesterol and a higher than-normal level of LDL-cholesterol are associated with a greater risk of having a heart attack, and conversely, that a higher-than-normal level of HDL-cholesterol and a lower-than normal LDL-cholesterol are associated with a smaller risk. Or, said in another way, a low HDL/LDL ratio is a risk factor for coronary heart disease. LDL in the presence of high HDL is made up of VLDL and mainly IDL. Low HDL is associated with smaller oxidised particles of VLDL. We will generally see high triglycerides with and elevated fasting blood sugar where HDL is low and LDL is high. Simple lifestyle changes correct this ratio.
However, a risk factor is not necessarily the same as the cause. Something may provoke a heart attack and at the same time lower the HDL/LDL ratio. Many factors are known to influence this ratio.
What is good and what is bad?
People who reduce their body weight also reduce their total cholesterol but may increase HDL and even in some cases LDL. In a review of 70 studies Dr. Anne Dattilo and Dr. P.M. Kris-Etherton concluded that, on average, weight reduction lowers cholesterol by about 10 per cent, depending on the degree of the reduction. Interestingly, it is only cholesterol transported by LDL that goes down; the small part transported by HDL goes up. In other words, weight reduction increases the ratio between HDL- and LDL-cholesterol.
An increase of the HDL/LDL ratio is called” favourable” by the diet-heart supporters; cholesterol is changed from” bad” to” good”. But is it the ratio or the weight reduction that is favourable? When we become fat, other harmful things occur to us. One is that our cells become less sensitive to insulin, fasting blood sugar increases and we become more susceptible to metabolic syndrome and diabetes. People with diabetes are much more likely to have a heart attack than people without diabetes. Atherosclerosis and other vascular damage occur very early in diabetics, even in those without lipid abnormalities. In other words, overweight may increase the risk of a heart attack by mechanisms other than an unfavourable lipid pattern.
Exercise decreases triglycerides which in turn reduces inflammation and the effect of oxidised LDL-cholesterol and increases HDL-cholesterol. In well-trained individuals on a well-balanced diet getting sufficient sunlight and rest, the ”good” HDL is increased considerably. In a comparison between distance runners and sedentary individuals, Dr. Paul D. Thompson and his colleagues found that the athletes on average had a 41 per cent higher HDL-cholesterol level. Most population studies have shown that physical exercise is associated with a lower risk of coronary heart disease, and a sedentary life with a higher risk. It also seems plausible that a well-trained heart is better guarded against obstruction of the coronary vessels than a heart always working at low speed. It could however also just be that individuals who train make maker lifestyle and nutritional choices.
Low HDL and high LDL is also associated with metabolic syndrome with conditions that include increased blood pressure, high blood sugar, excess body fat around the waist, and abnormal triglyceride levels.
Univariate and multivariate
A calculation of the risk of high LDL-cholesterol that ignores other risk factors is called a univariate analysis and is, of course, meaningless. To prove that high LDL-cholesterol is an independent risk factor, we should ask if fat, sedentary, smoking, hypertensive and mentally stressed individuals with a high LDL-cholesterol level are at greater risk for coronary disease than fat, sedentary, smoking, hypertensive and mentally stressed individuals with low or normal LDL cholesterol. Using complicated statistical formulas, it is possible to do such comparisons in a population of individuals with varying degrees of the risk factors and varying levels of LDL-cholesterol, a so-called multivariate analysis.
That a high LDL-cholesterol isn´t bad appears from over 19 identified studies, where the authors had followed almost 70,000 individuals under several years after having measured their LDL-cholesterol. At follow-up they noted that those with the highest LDL-values lived the longest; even longer than those on statin-treatment.
Your metabolic risk profile can be generally determined by completing a blood test that measure your fasting blood sugar (hba1c ), serum lipids and Vit D. Observations over many years have shown us that your risk is minimised if your hba1c is less than 5.5 %, triglycerides less than 1ml/mol, HDL at or above 1.8ml/mol and Vit D above 50ng/ml.
Where these values are below the recommendations both lifestyle and nutritional changes are required to correct and avoid the associated risks.
Charles Lubbe is the author of the Big Breakfast Debate and 7 Day Meal plans and a passionate advocate for correcting, weight , health and serum lipids.
Contact 0717287835 or email firstname.lastname@example.org