Low Cholesterol and Cancer – Is there a Link?
It has been known for decades that cancer patients have low levels of LDL cholesterol. However, we never took it seriously, thinking that the reduction was simply a consequence of already developed preclinical cancers, which are increasing the body’s cholesterol demands, concluding that this association was an effect and not a cause of cancer.
But, now this has all being turned on its head and we need to give it a serious rethink. The American College of Cardiology presented the new data at its recent symposium, showing that low LDL cholesterol levels occur already before and thus predict cancer occurrence. This is valid up to 19 years before clinical manifestation of cancer. So in simple words, you have low cholesterol levels first and then the cancer occurs, not vice versa as previously believed. This new finding adds to a growing body of evidence, suggesting the same thing and thus supports the hypothesis that having lower LDL cholesterol levels could actually be a cause of cancer.
Now we start realising that cholesterol is not just the ‘deadly’ substance we have been led to believe but it also plays an unrecognised vital role in our health. Evidence indicates that cholesterol can bind, isolate and neutralise carcinogenic material (incl. viruses and bacteria), thus preventing them from causing harm in the body. In addition to that, we need adequate cholesterol levels to ensure optimum key hormone formation that are essential for our health.
Statins vs Cancer
Given all this evidence, we cannot help but turn our attention to the extensive use of cholesterol lowering drugs called statins. Hundreds of millions of people worldwide take these drugs. Could it be that we take statins to lessen our risk of heart disease, only to balance it out with increasing our risk of cancer? Indeed, there have been some studies to suggest that statins could increase cancer risk for such types of cancer as lymphoid, skin, prostate, breast and bladder cancer within just a few years. However, when it comes to the overall evidence, a meta-analysis of fifteen randomized controlled trials of statin use found no increase in cancer incidence, putting any previous correlations down to chance.
One of the arguments often mentioned regarding this meta-analysis is that the studies lasted on average only 4.5 years. But with cancer there is a lag time between exposure to the cancer causing element and its clinical manifestation of 10 to 20 years. And the types of cancers that have been suggested to be caused by statins are those quickest to clinically present from initiation. But still the supportive evidence for a cancer link becomes fragile in this light. For example, in one study most commonly quoted to implicate statins in cancer formation about half the increase in cancers observed occurred in the first two years of a five year trial. This appears an implausibly quick period of time for solid cancers to come into full clinical detection. For instance, bronchial cancer will typically take ten years or more of heavy smoking to surface. Even if true, as time passes a trend of an increased rate of cancer occurrence would be the expected consequence, but this was not the case. Hence, it is likely that the findings of this study were simply down to chance. This notion of chance gains even more credibility when we see that at the end of last year a five year study of 20 thousand individuals using statins released a six year follow up (that is eleven years in total) and found no impact on cancer incidence.
Interestingly, although the statin meta-analysis found no association between the use of statins and increased cancer risk, the authors did find an increased cancer risk in those with lower LDL cholesterol levels. It makes little sense though, as if the study finds lower cholesterol increases cancer risk, then lowering the cholesterol further through cholesterol lowering drugs would have to increase this risk even further. We have to ask how this is feasible. Perhaps LDL cholesterol is simply a confounder. In other words, another biochemical process or measurement that predisposes us to cancer also happens to cause low LDL levels, thus the cholesterol lowering action of statins has no effect. Maybe there are different types of LDL particles and those that are cancer protective are not diminished by cholesterol lowering drugs. Or maybe even the 11 years of the last follow up study is not long enough, needing more like 15 to 20 years, though it sounds unlikely.
So, when we get down to the details, we realise that while we cannot blame statins per se, we really do not understand the full role of the LDL cholesterol in the body. And although no one would argue with intervening when cholesterol levels are too high, we must question our obsession with trying to get our levels as low as possible through drugs and diet alike when we do not understand the possible consequences.
Where to Find Related Information: The Truth About Cancer