Cholesterol from your diet or that produced internally by the body is carried in the bloodstream bundled into complexes called ‘lipoproteins’, which means fat-proteins, ‘lipo’ meaning fat. There are diffent types of lipoproteins classified by how dense they are, that is, how much protein they include. These include high density (HDL), low density (LDL), intermediate density (IDL) and very low density (VLDL) lipoproteins. In addition, the actual particle size has a bearing on what sort of risk they carry for heart disease. (The big fluffy particles are better to have than the small, heavy ones apparently.) It’s a complex situation inside your metabolic environment.
The importance of HDL
The high-density lipoproteins (HDL) do a valuable job in scavenging excess cholesterol from circulation and returning it to the liver for excretion. For this reason, HDL is often called the ‘good’ cholesterol. However, more recently, HDL has been found to have additional properties such as anti-inflammatory and antioxidant behaviour. More focus is being placed on increasing HDL, especially in cases where LDL (bad cholesterol) lowering has not been sufficiently effective.
Cholesterol is an essential fat-like substance (sterol) important in the production of sex hormones and for maintenance of cell membranes. The body produces some naturally and then regulates its production based on how much cholesterol we consume. If we have too much cholesterol in the bloodstream, particularly the small, heavy low-density lipoprotein cholesterol (LDL), some gets oxidised, deposited in arteries and causes artery disease which may result in a heart attack eventually. However, if you have sufficient HDL to scavenge the excess, your heart disease risk will decline because LDL does not get a chance to build up in arteries.
Excess saturated fat from animal foods, coconut and palm oil in the diet, and the trans fatty acids, disrupt the way cholesterol receptors work so the body does not regulate cholesterol production and processing as well.
Women, before menopause at least, usually have higher HDL than men — women greater than 50+ mmol/L (1.3 mg/dL) and men greater than 40+ mmol/L (1.05 mg/dL). Below these numbers is entering higher risk territory for coronary artery disease for either sex.
By raising HDL and lowering LDL or at least not raising LDL at the same time, heart disease risk can be reduced. A ratio of total cholesterol to HDL cholesterol of 3.5 is said to be protective, as is a HDL level above 60 mmol/L (1.55 mg/dL). It depends on your other risk factors: family history, blood pressure, blood glucose, hypertension, obesity, inflammation and so on, but total cholesterol below 4.0 mmol/L (155 mg/dL) is considered to infer very low risk for cardiovascular disease if maintained in good health over an extended period.
How to raise HDL with Lifestyle
HDL seems to be affected by the following nutrition and physical activity principles, so it’s worth trying to raise HDL while reducing LDL at the same time. This is not easy because it is somewhat contradictory.
– Regular physical activity, probably at moderate to high intensities and duration
— Low-GI and/or high-fibre diets
— Mono- and polyunsaturated fats when they replace refined carbohydrates and trans fats
— Reduced waistline and body fat; slimmer equals better
— A decrease in blood triglycerides often increases HDL
— Red wine and perhaps other alcoholic drinks ( not in excess, 1-2 glasses/day)
— Stop smoking
— Trans fats (in fast foods, commercial foods)
— Anything that raises triglycerides (blood fats), tends to lower HDL (overeating, excess alcohol, refined carbohydrates, sugars, low physical activity)
— Alcohol in excess
— Refined, high-GI carbohydrates and sugars
— Reduced physical activity
— Increased body fat
You can probably see from the above, that just following a very low-fat diet won’t necessarily do it, even if it helps reduce LDL cholesterol. You need to make sure you include plenty of fibre and some healthy fats and exclude the highly refined carbohydrates such as biscuits, white bread, cakes, fries and added sugars and excess alcohol. Eating these foods tends to induce the body to constantly use the glucose or alcohol pathways for energy in preference to fat as fuel, thus raising the level of fats (triglycerides), which in turn lowers HDL in liver.
This becomes a vicious circle as insulin sensitivity decreases and glucose tends to stay high in the blood and the triglycerides spike and HDL plummets — and that’s what metabolic syndrome is.
Summary of HDL
Except for people who have a genetic predisposition, low HDL is essentially a disorder of fat and glucose metabolism as a result of too much fat and refined carbohydrate eaten in excess of energy requirements. Under these circumstances, the higher the blood sugar and fat load on your system, the lower the HDL and the higher your blood triglycerides will be.
Lose weight, or at least body fat, eat a high-fibre diet — and with exercise quality, quantity and consistency — most people will see an increase in HDL. A small tipple of red wine may also help. If you exercise consistently at moderate to high intensity and you are of normal weight, you can worry less about portions of high-GI and refined carbohydrates.
For healthy fats, nuts, avocados sunflower seeds and fish oils in whole foods are good choices but be aware of excess energy intake. Choose only modest portions of quickly metabolised carbohydrates such as white bread and pastries and go for heavy wholegrain breads and cereals, fibre-rich beans and plenty of coloured vegetables and whole fruits rather than juices.
Consult your doctor first
Even so, some individuals do not respond to lifestyle interventions to raise HDL. Fortunately drugs such as niacin in special formulations can help, for which you need to consult your doctor. You should also consult your doctor before making any radical changes in diet and exercise, particularly in relation to alcohol consumption and particularly if you are diabetic.
© Paul Rogers