Vital Information About Cholesterol!
Cholesterol is a waxy, sticky, fat like substance produced in the liver and is also present in our food.
Most people only know that it causes heart disease, few know that it is an essential constituent of our body and has a vital role to play in our health.
Functions of Cholesterol:
Cholesterol provides structural support to every cell of our body as it is an essential constituent of the cell membrane and plays a significant role in deciding what goes in or out of the cell membrane.
It also helps form the protective myelin sheath of our nerve cells.
It is essential for the synthesis of steroid and sex hormones and for the formation of Vitamin D under the skin when exposed to sunlight.
It is also essential for the formation of bile which is, in turn, essential for digestion of fats.
LDL and HDL Cholesterol:
Cholesterol is insoluble in water. So it has to be transported in blood in complex fat and protein molecules called lipoproteins. Cholesterol moves through our body inside these lipoproteins.
LDL or low density lipoproteins transport most of the cholesterol in the plasma, from the liver to the peripheral tissues where it is used for building the cell membranes of every cell of the body and to the adrenal glands and gonads where it is used for synthesising steroids and sex hormones.
Excess build up of low density lipid cholesterol in the blood can enter the arterial walls causing plaque formation and atherosclerosis, leading to narrowing of the arterial walls causing ischaemia or reduced blood supply to the heart or any tissue of the body and could lead to myocardial infarction or heart attack and strokes.
And if a plaque breaks away, it could block the arteries of the heart or the brain causing heart attacks or stokes.
HDL lipoproteins transport cholesterol from the tissues and the arteries to the liver which excretes it from the body, protecting it from heart disease and strokes.
This is called the reverse cholesterol transport system.
This is why the HDL cholesterol is considered the good and the LDL cholesterol the bad cholesterol.
Our liver is capable of providing us all the cholesterol we need. We don’t need to consume it in food.
Only animal sources of foods such as flesh, eggs, shell fish, whole milk, cream, ghee, butter, cheese and margarine have cholesterol. No food of vegetable source has cholesterol.
Cholesterol And Heart Health
Excess cholesterol in the blood is bad for the heart.
The HDL cholesterol is the healthy cholesterol, while the LDL and the VLDL cholesterol are bad for the health of the heart.
HDL cleanses our arteries by transporting cholesterol from the arteries to liver and cleansing the arteries, thus protecting us from coronary heart disease.
The latter two transport cholesterol from liver to the arteries, where it sticks the walls of the arteries, which become hardened and lose their elasticity, causing atherosclerosis and clogging of the arteries leading to coronary heart disease.
Saturated fats in our food are actually more responsible for raised levels of cholesterol in our body than dietary cholesterol. Animal products including whole milk, eggs and flesh and vegetable fats which are solid at room temperature (e.g. palm oil, coconut oil) are examples of saturated fats.
This means vegetarian people too are going to suffer from raised levels of cholesterol, if they eat fatty and sweet foods in excess.
Genetically too some people are more prone to have high levels of cholesterol as their livers manufacture excess cholesterol.
Trans-fatty acids also are equally to blame for raised levels of cholesterol. In fact they are rated as worse than cholesterol for the health of the heart. Hydrogenated vegetable oils and oils in which food stuffs are fried over and over, again and again, develop trans-fatty acids. Many bakery products and ready to eat snacks are made using hydrogenated vegetable oils as it gives them longer shelf life. Most people who never use hydrogenated oils at home, eat these products without realising that they are consuming hydrogenated oils.
White Meat And Red Meat
The thinking till recently has been that it was red meat that was mainly responsible for raising your blood cholesterol levels and was dangerous to the health of our heart and that it was safe to eat white meats.
But according to study published in the ‘American Journal Of Clinical Nutrition’ the researchers of the ‘University Of California’ have found that white meat can also raise your blood cholesterol and is as bad as red meat for the health of our heart.
So stop eating white meat blissfully imagining that it is heart healthy!
Dietary Fibre and cholesterol:
Soluble fibre dissolves in water, forming a gel like substance that absorbs cholesterol and sugars and clears them out of our bowels, reducing their absorption in our blood stream, thus helping lower blood cholesterol, especially LDL, the bad cholesterol, triglycerides and sugar. Thus it helps lower the risk of diabetes, heart disease and strokes.
Soluble fibre sources are oats, pulses and legumes, apples, citrus fruits, carrots, barley and psyllium (isabgol).
Abdominal obesity and cholesterol:
Abdominal obesity leads to raised levels of blood pressure, blood sugar, total cholesterol, LDL cholesterol and triglycerides and lowers the levels of HDL cholesterol.
This is called the Metabolic Syndrome.
It leads to heart disease and strokes.
Effect Of Smoking On Cholesterol:
Tobacco smoke damages the endothelial lining of the arteries and causes inflammation, making it easier for the white cells and platelets to clump together and stick to the damaged endothelium and cause clot formation.
Burning of tobacco releases fumes which include many toxic substances including acrolein. Acrolein renders the bad cholesterol, the LDL cholesterol more sticky and it sticks more easily to the endothelium of the arteries and white blood cells and other substances stick to it and plaques are formed in the arteries narrowing them. It also interferes with the ability of HDL cholesterol to remove the plaque build up and keep the arteries blockage free.
Thus smoking causes damage and inflammation to the endothelium of the arteries leading to atherosclerosis and also damages the LDL and HDL cholesterols preventing them from functioning properly and leads to heart disease and strokes.
Effect Of Alcohol On Cholesterol:
Drinking alcohol raises the levels of the triglycerides in your blood and build up of triglycerides in liver leads to fat build up in the liver and leads to fatty liver disease. Damaged liver cannot remove the cholesterol from your blood efficiently and this leads to raised blood levels of cholesterol and eventually to heart disease and strokes.
Normal Levels Of Cholesterol
Ideal levels of cholesterol and it’s components are:
Cholesterol below 200 mg/dL
HDL cholesterol above 60 mg/dL
LDL Cholesterol below 100mg/dL. Some physicians want it below 70mg/dL
VLDL Cholesterol below 30 mg/ dL
Triglycerides below 150 mg/dL
Normal range is always provided by every laboratory in its report.
Dietary Cholesterol Guidelines
Until 2013 it was generally accepted that dietary consumption of cholesterol should not exceed 300 mg daily for people who are not at a risk of developing coronary heart disease and 200 mg daily for people who are at a risk of developing coronary heart disease.
But research across the world could not establish a direct link between dietary cholesterol and raised blood cholesterol and LDL cholesterol and cardiovascular disease risk and hence the contemporary guidelines for coronary heart disease risk reduction from the American Heart Association (AHA) and American College of Cardiology (ACC) and the 2015–2020 Dietary Guidelines for Americans (DGA) have not issued explicit guidelines for consumption of dietary cholesterol.
But most of the high cholesterol foods, viz. full cream milk and animal flesh are also high in saturated fats.
So eating these high cholesterol foods also adds excess saturated fats to your diet.
Also the two diets highly recommended for prevention of heart disease, the Mediterranean Diet and the DASH Diet are both low cholesterol diets.
So even if there is insufficient evidence that dietary cholesterol raises blood cholesterol significantly, it is prudent to keep your dietary cholesterol consumption low.
A whole egg provides 210 mg cholesterol, goat meat provides 75 mg per 100 gm, chicken 85 mg, lamb, pork and beef between 85 to 105 mg, sea food provides between 50 to 100 mg cholesterol per 100 gm. Liver of the above animals provides the highest levels, between 350 to 650 mg per 100gm!
Prawns and other shell fish may contain upto 190 mg cholesterol per 100 gm, but it helps lower LDL cholesterol and increase HDL cholesterol and thus is heart healthy according to American Journal Of Clinical Nutrition.
Sea fish including shell fish are low in saturated fatty acids and high in sea source omega 3 polyunsaturated fatty acids. Prawns are low calorie and high in the potent antioxidant astaxanthin, a carotenoid. Hence eating fish and prawns in moderation is healthy.
Keeping Your Cholesterol Levels Healthy:
Lead a healthy lifestyle.
Eat healthy, focussing on skimmed milk and dairy products, whole grain cereals and pulses, ample vegetables and fresh fruits on daily basis and have fatty fish rich in omega-3 fatty acids twice a week.
Most Indians have no problems consuming whole grain cereals, pulses and vegetables as that is what our food basically consists of. What we most often may not consume adequately are skim milk and fruits. Ideally we should have three helpings of both!
Keep consumption of saturated fats to the minimum and trans-fats out of your food. Eat only lean meat, that too in moderate amounts and frequency. Have a whole egg no more than four days week, even if your cholesterol is fully normal.
Make sure to include oats, pulses and legumes, apples, citrus fruits, carrots in your regular diet to consume adequate soluble fibre.
Exercise regularly and be physically active. Even a half hour brisk walk, spread over the whole day, will be invaluable, half an hour twice a day will be wonderful even for losing weight!
Lose weight and get rid of your paunch.
Stop smoking.
Drink alcohol minimally or better quit drinking.
Be mentally happy and peaceful.
In short to keep your cholesterol levels healthy, you do exactly what is needed to be done to be slim and heart healthy!
Read the article ‘Basics Of Nutrition’ on this website for more information.
Boosting Your HDL Cholesterol
Many people have normal total cholesterol but low HDL cholesterol, the cholesterol that cleanses your arteries by removing cholesterol build up within them and prevents coronary artery disease.
The following six steps will help boost your HDL cholesterol levels.
1. Get regular exercise. Regular walks, even half an hour every day, can give you much better heart health than being couch potato!
2. Lose weight. Even four kg loss can dramatically lower your bad cholesterol (total cholesterol and LDL cholesterol) and boost your HDL cholesterol.
3. Eat healthy fats viz. omega 3 rich sea fish, cold pressed cooking oils like groundnut oil, sesame oil and olive oil and walnuts and flaxseeds. Reduce unhealthy fats viz. saturated fats coming from milk viz. cream, butter, ghee, cheese, full cream paneer and fatty meats. Stop consuming foods made from hydrogenated oils, they are loaded with trans fatty acids which can cause more damage to your coronary arteries than cholesterol.
4. Stop smoking.
5. Reduce your alcohol consumption.
6. Consult your physician.
Also read the articles ‘Basics Of Nutrition‘ and ‘The Good And The Bad Fats‘ on this website.