A new review of previous studies has found that higher levels of 'bad' LDL cholesterol are not associated with increased mortality risk in people over 60 years old. In fact, some studies found that higher LDL levels were linked to lower mortality rates in this age group.
LDL cholesterol, which stands for low-density lipoprotein cholesterol, is often referred to as 'bad' cholesterol. It's one component of total cholesterol in our blood. While total cholesterol includes several types of lipoproteins, LDL cholesterol has been the focus of much research and treatment because it's traditionally been thought to contribute to the build-up of plaque in arteries, potentially leading to heart disease and strokes.
The review examined 19 studies involving over 68,000 people aged 60 and older. In 16 out of 28 studies examining all-cause mortality, higher LDL was associated with lower death rates. Notably, no studies found a link between higher LDL and increased mortality risk. For cardiovascular mortality specifically, seven out of nine studies found no association with LDL levels.
The researchers say these results contradict the common belief that high LDL cholesterol increases heart disease and mortality risk. This is particularly surprising because, as the study authors note, atherosclerosis and cardiovascular disease are mainly diseases of the elderly. If LDL cholesterol were truly a primary cause of these conditions, one would expect to see a strong association between LDL levels and mortality in older adults.
The researchers suggest several possible explanations for why higher LDL may be protective in older adults. LDL may help fight infections and neutralise toxins, higher cholesterol may protect against cancer, and low cholesterol could increase susceptibility to certain diseases. They also note that LDL has been shown to bind to and inactivate a range of microorganisms and their toxic products, which could explain why lower LDL levels might be associated with higher mortality from certain causes.
However, the authors emphasise that more research is needed to understand the relationship between cholesterol and health outcomes in the elderly. They suggest current guidelines on cholesterol treatment for older adults may need to be re-evaluated.
Patients should discuss their individual cardiovascular risk factors and treatment options with their doctor. This study does not prove that high cholesterol is beneficial, but raises questions about how it affects health in later life.
