Most doctors who check cholesterol levels will order a ‘lipid panel’ – a blood test which measures levels of total cholesterol, low density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C), and triglycerides. Conventional wisdom tells us that, on the whole, cholesterol is a bad thing, particularly LDL-C. While HDL-C is generally regarded as a good thing (associated with a reduced risk of cardiovascular disease).
Most doctors I come across are more moved by total cholesterol levels. Once this goes beyond 5.0 mmol/l (193 mg/dl) alarms bells ring for many doctors. I’ve lost count of the number of patients I’ve seen with cholesterol levels in the high 5’s or around 6 who have been told to ditch the fat and get exercising, and if that doesn’t work to bring cholesterol down, they are told to seriously consider statins.
Even if raised cholesterol is associated with an increased risk of, say, heart disease, the only really important thing is if cholesterol reduction (as we doctors often urge people to undertake) is beneficial. Most doctors, I think, would swear blind that there’s really no doubt about the benefits. Yet, several strategies (including more than one type of drug) that are effective in lowering cholesterol have not brought benefits for cardiovascular health. Some actually make matters worse. The bottom line is that cholesterol reduction per se is not guaranteed to bring health benefits, and may actually hasten cardiovascular disease and even death.
However, even before we get to these crucial issues, we might at least ask if the relationship between cholesterol levels and health is as clear-cut as we are so often lead to believe. I recently came across a study which, like others, casts some doubt on the notion that higher cholesterol levels are inherently bad for our health.
The study was conducted in men with an average age of almost 77. About three-quarters of the men neither had a history of cardiovascular disease nor were taking a statin drug. The rest of the men either had a history of cardiovascular disease or were taking a statin.
Here’s a brief summary of the relationship between total cholesterol, LDL-C and HDL-C levels and risk of death from heart disease in the men:
High HDL-C levels were associated with a reduced risk in the group of men who had a prior history of cardiovascular disease or were taking a statin. When all the men were lumped together, higher HDL-C levels were still associated with a lower risk of death from heart disease.
Higher LDL-C levels were associated with an increased risk of death from heart disease, but only in the men with no history of cardiovascular disease. When all the men were analysed together, higher LDL-C levels were NOT associated with an increased risk.
Total cholesterol was associated with an increased risk of death from heart disease but, again, only in men with no history of cardiovascular disease. When all the men were analysed together, higher total cholesterol levels were NOT associated with an increased risk.
Another parameter assessed by the authors of this study was the ratio of total cholesterol to HDL-C, with higher ratios generally viewed as a bad thing. Here, higher values were associated with an increased risk generally, but this was not true in the group of men with a previous history of cardiovascular disease or taking a statin.
What this study shows is that the standard ways of assessing heart disease risk in this population lack consistency and do not appear at all reliable. The fact that in the population as a whole, neither total cholesterol nor LDL-C was associated with an increased risk of death from heart disease should perhaps cause us to question the basis on which we make recommendations regarding cholesterol management.
Here’s to a healthy heart
Dr John Briffa
for The Cholesterol Truth
Bear in mind we are not addressing anyone’s personal situation and you should rely on this for informational purposes only. Please consult with your own physician before acting on any recommendations contained herein.
1. Clarke R, et al. Cholesterol fractions and apolipoproteins as risk factors for heart disease mortality in older men. Arch Intern Med 2007;147(13):1373-1824
Category: Latest Cholesterol Research