Friday, August 8, 2008

Cholesterol Conundrum: A reality check.

Most people think that Cholesterol is a fat, which; strictly speaking; it is not. This myth took root because Cholesterol, being a highly fat-soluble substance and being insoluble in water, is found in fatty tissues of animals. The fact however, is that cholesterol is a form of alcohol. There are many types of alcohols and cholesterol is a very large and complex alcohol molecule, modified and tampered in certain ways. As you know, all alcohols are made from sugars and starch-rich substrates, so is cholesterol. It is made in liver, from Acetyl Co-enzyme A, which ultimately uses glucose, amongst others, as a substrate. Glucose is the simplest carbohydrate. All other forms of carbohydrates ultimately get broken down to glucose in the digestive system. Therefore, the real culprit in causing excess cholesterol build up in our system is carbohydrate overload through excessive consumption of sweet and starchy foodstuffs and NOT excessive fat intake. Fats derived from animal sources do contain certain amount of cholesterol, but the quantities involved are so small that overall, it does not matter. Further, due to a process called “Feed Back Inhibition”, the cholesterol content of foodstuffs by-and-large becomes irrelevant. Paradoxically, approximately 100 grams of fat intake per day; in the form of butter or ghee; leads to lowering of cholesterol level. This runs contrary to the oft-repeated medical advice that fats are not heart friendly due to their cholesterol content. Well, this is what we all thought initially, but in the light of new research based facts emerging, this concept has been discarded. Only noteworthy caution in this matter however is that fried fats still are considered unhealthy, because the process of deep frying causes changes in molecular structure of fats, leading to formation of Trans-Fatty Acids, which are harmful.
Vegetable oils and Vanaspati ghee do not contain cholesterol at all, for the simple reason that cholesterol is found only in the animal world. In the plant world, it is non-existent. Therefore, only eggs, meats, milk & milk products and all such foods coming from animals only can contain cholesterol. Any food; including fats; sourced from plants is free from cholesterol. Based upon this concept vegetable oils and vanapati ghee were considered safer compared to butter & butter oil (ghee). But new research findings have turned this belief upside down. Now, as we know that cholesterol content of natural ghee is just a bogey, and we know that vanaspati ghee contains Trans Fatty Acids (even in un-fried form), therefore natural ghee is safer; inspite of it’s cholesterol content; than vanaspati ghee, despite it being free of cholesterol.
Do you know that cholesterol-free polyunsaturated fats such as in sunflower oil are actually more harmful than natural ghee, because of their exceedingly low content of Omega-3-fats and exceedingly high content of Omega-6-fats? The ratio between these two special types of fats in healthy diet (fat component of diet) should be 1:4. In sunflower oil it is 1:50. But in natural ghee, it is a healthy 1:6. An unhealthy ratio increases the clotting tendency in blood, which, in turn, is one causative factor amongst many (yes! There are many, cholesterol is not the only one) for heart disease and heart attack.
The other day, a patient promised to me; upon my advice; that he will exercise regularly; then onwards. Then he added, “I realize that exercise will not only keep me fit, it will also burn my cholesterol away”. No, exercise does not burn cholesterol. But it helps in bringing cholesterol level down through reducing carbohydrate load in the body. This leads to reduced levels of free glucose intracellularly (within body cells, esp. liver cells), and it also increases Insulin sensitivity, leading to lower level of Insulin hormone in circulation. It has been known to medical scientists for a couple of decades that high blood levels of Insulin hormone somehow increase cholesterol formation and low levels of the same have the opposite effect. How exactly this happens is still under investigation and is not clearly known. Point to be stressed here is that cholesterol reduction as a result of exercise is neither due to burning of cholesterol, nor due to burning of fat, but it is due to burning of glucose. Principal fuel utilized by our muscles during exercise, is glucose, because it yields energy very quickly. The process, through which fats yield their energy inside our bodies, is very slow. Therefore, through evolution, our metabolic processes have been designed in such a way that during resting state, the principal fuel for energy requirements is fat and glucose is conserved to provide a source of instant energy during physical activity/ exercise. Therefore, even as mild an exercise as simply walking does wonders for cholesterol reduction, as each step you take burns between five and ten milligrams of glucose.
It will not be out of place here to mention that the pattern of diet which we were recommending till now (Carbohydrates 80%, Fats 10% and Proteins 10%) has turned out to be disastrous, as shown by experience and scientific scrutiny. Actually it is suited for people who undertake hard labour as a way of life, burning 4000 or more Calories per day, wherein fat intake will work out to be between 100 and 150 grams per day. But the lifestyle for the past few decades has been such that even farm labour is no more hard labour, due to mechanization, and average daily Calorie requirement has come down to less than 2000 Calories per day. Here the point to remember is that the reduction in Calorie requirement; between the old and the new order; has been in the realm of glucose burning Calories (muscular activity). The proportion of fat burning Calories (resting state energy requirement), if at all, has increased. Therefore, mindlessly applying the old formula for today’s sedentary population and cutting down the fat intake to no more than 20 grams per day; for misplaced fear of cholesterol, was a big mistake, resulting in the epidemic of Diabetes and Heart Disease today. The recommended proportion of Calorie content of diet for today’s lifestyle is Fats: 60%, Carbohydrates: 30% and Proteins: 10%, which is a slight modification of famous and popular “Atkins’ Diet”. This will translate to between 100 and 150 grams of visible (added from outside as free fat, as opposed to invisible fat, which is incorporated in all foodstuffs) fat intake per day. As a ready reckoner, add 25 to 30 grams of butter or ghee to each of your three meals, use soybean, mustard, groundnut or olive oil (no sunflower oil) for cooking; avoid fried foods and knockout sugar, rice and white bread (and all other preparations containing maida) from your diet, take as many chapattis as you feel like (you’ll not feel like having many with so much visible fat added because satiety value of fat is four times that of Carbohydrates, though the calorie content is a little more than double. Therefore, fat intake makes you feel full with small quantities). With this kind of a diet; which is rather fat rich and more palatable; you’ll be keeping your cholesterol levels surprisingly low. But even a bigger and pleasant surprise will be the weight loss contrary to your apprehensions of weight gain, believe me.

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