Understanding cholesterol: The myths and the facts
Cholesterol (a type of fat or lipid) was discovered in 1910 by a German chemist named Adolph Windaus. He was able to show that the atherosclerosis plaque (fat deposits) from human diseased aortas (Main blood channel which comes out of the heart) contained cholesterol in 20 to 26 times the concentrations found in healthy aortas. High cholesterol level affects millions of people worldwide and is a major risk factor for cardiovascular disease which nearly half of all men and a third of women will get at some point in their life.
I’ll spend the majority of this blog on things my patients inquire about most: What does my cholesterol level mean, how cholesterol and heart disease are connected and what they can do to optimize their cholesterol levels. The knowledge of how body makes cholesterol usually forms the basis of all “successful” cholesterol lowering plans.
But hang on, what actually is cholesterol?
Cholesterol is a wax like substance which would flows in our blood combined with certain other fats and proteins in the form of “lipoproteins”. The two most important lipoproteins are Low density lipoproteins (60-70% of total cholesterol) or LDL “the bad cholesterol” and High density lipoproteins or HDL “the good cholesterol”. Triglyceride “the not so important one” is the third most common type of fat in the body and has recently been found causative of plaque buildup in human arteries.
The total cholesterol score (which is reported by the laboratories) is calculated using the following equation: HDL + LDL + 20 percent of your triglyceride level.
I look after my diet pretty well so how does it cholesterol build up in my body?
Cholesterol content in the human body depends upon certain hereditary, behavioral and co-existent disease conditions.
Hereditary (genetic) conditions like “familial hypercholesterolemia” run in families and can be responsible for early or “premature” development of coronary heart disease. Certain genes, obesity and excessive endogenous production of cholesterol in the liver are usually some of the factors responsible for the high levels of cholesterol in these patients.
Coexistent diseases such as diabetes mellitus type 2 (formerly known as adult onset or non insulin dependent diabetes mellitus), obesity, alcoholism, dialysis, anorexia nervosa, underfunctioning thyroid gland and Cushing’s syndrome are some of the commonly encountered medical conditions responsible for high cholesterol levels. In addition, certain medications such as beta blockers, certain (thiazide) diuretics and steroids etc are also responsible for increasing cholesterol concentration in the human body.
If cholesterol is so “bad” do we really need it?
Extensive research has been performed on cholesterol over the course of the last century which has proven it to be “essential to life but deadly in excess” entity.
Despite the bad press it receives, cholesterol is an essential nutrient required by human body to aid in repairing damaged human tissues, manufacturing vitamin D on the skin’s surface, synthesizing steroid based hormones, such as estrogen and testosterone, bile acids that work to digest food and cell connections in the brain essential for learning and memory.
Ok that sounds great, then why is it bad and why does every doctor warns me against it?
Well, its actually the “excess” of “bad cholesterol” or LDL which is harmful and that’s what the doctors usually want you to work on. A diet high in saturated and trans fats raises LDL cholesterol. The “good cholesterol “ or HDL is actually preventive against development of heart disease. Smoking, being overweight, type 2 diabetes, steroids and a sedentary lifestyle lower its concentration in our body. High levels of HDL (above 60 mg/dL) may be nearly as protective for the heart as low levels of LDL (although drugs aimed at increasing HDL to excessively high proportions have failed to show significant preventative benefits).
Triglycerides have traditionally been considered “not so important” but it is safe to say in the light of recent research that a high triglyceride level combined with low HDL cholesterol or high LDL cholesterol is associated with atherosclerosis or plaque buildup on the walls of our body’s blood channels (arteries),that increases the risk for heart attack and stroke “brain attack”.
The American Heart Association (AHA) recommends all adults age 20 or older have their cholesterol, and other traditional risk factors, checked every four to six years.
So what can I do to help it?
As I previously mentioned, a “successful” cholesterol lowering plan starts with understanding the mechanism of cholesterol buildup in our body. Now that we know what causes high levels of bad cholesterol it should be easier to understand the mechanics of the “usually” prescribed plans. Every plan starts with a baseline measurement of fasting lipid profile
Lifestyle changes form the foremost basis of any cholesterol lowering regime. These changes are aimed at both “lowering the bad cholesterol” as well as “increasing the good cholesterol.”
The bad “LDL” cholesterol can be lowered by a diet consistent of low-cholesterol foods, reduced saturated fats and trans fat.
The good “HDL” cholesterol can be increased by smoking cessation, limiting alcohol consumption, increasing physical activity, and maintaining a healthy weight. Eating oatmeal, raw walnuts, oily fish such as salmon, trout etc, green vegetables, avoiding fast foods such as fried burgers and French fries are some of the important dietary modifications we can make to achieve lower cholesterol counts. Smoking cessation ,weight reduction (more importantly keeping the ratio of waist to hip measurement lower than 1.0 in men and less than 0.8 in women) and an exercise program that stresses on brisk walking or aerobic exercise for approximately 20-30 minutes five times a week are some of the lifestyle modifications we can inculcate in our life that can be beneficial.
Some of the above mentioned maneuvers affect both types of cholesterol. All that said, even the most rigorous lifestyle changes usually account for 10-15% reduction in total cholesterol levels.
For people whose cholesterol levels run significantly high or who have suffered a heart attack or a stroke, cholesterol lowering drugs become a necessity. Many drug classes are routinely used including but not limited to fibrates, niacin and most importantly the statins or the “wonder drugs”. Out of all the different classes, statins are by far the most commonly prescribed and the most effective. They work by blocking substances used by your body to create cholesterol and by helping your body to re-absorb cholesterol it makes. They do have their side effects which limit generalization to everyone.
Strict “adherence” to above-mentioned lifestyle and medication therapies along with regular follow ups with your physician underscore a successful long term cholesterol lowering plan.