A large-scale review study reports that HDL cholesterol (HDL-C), which has been associated with good heart health for some time, may also be linked to a significantly reduced cancer risk. The study comes from researchers at the Tufts Medical Center Molecular Cardiology Research Institute in Massachusetts.
The new research, led by Richard Karas, analyzed data from 24 earlier studies that looked at how using statin drugs to lower cholesterol affects risk of heart disease. There were over 145,000 participants included in total, some of whom had taken statins to reduce LDL (aka “bad”) cholesterol, and some of whom had not (serving as controls). The studies also tracked the occurrence of cancer, which allowed Karas and his team to correlate HDL-C with cancer risk.
The team found that for every 10 mg/dl rise in HDL cholesterol, there was a 36% reduced risk of cancer. These impressive results held true even when other variables related to cancer risk were controlled for, like smoking, age, body mass index, and LDL cholesterol levels. The authors do caution that “[a]s with all association studies, the present study should not be interpreted as implying a causal relationship between low HDL-C levels and cancer risk.” In other words, there may be other variables besides HDL-C that are responsible for the reduced risk of cancer.
In an editorial that accompanied the article, Jennifer Robinson suggests one possible explanation for the link between HDL and reduced cancer risk is that “HDL may have other antiatherosclerotic, as well as anticancer, effects attributable to its antioxidant and anti-inflammatory properties.” In other words, it may act as an antioxidant or anti-inflammatory agent, thereby reducing the risk for cancer: and, as Karas and colleagues write, “[c]ancer is well-known to be a proinflammatory state.”
What’s clear is that there is a robust relationship between higher HDL-C and lowered cancer risk. Now it will be a matter of figuring out just why the relationship exists – and this may be easier said than done.
