Study says there's no link between cholesterol and heart disease
Mon, 13 Jun 2016 12:33:00 EST
"Controversial report claims there's no link between 'bad cholesterol' and heart disease," the Daily Mail reports, while The Times states: "Bad cholesterol 'helps you live longer',".
The headlines are based on a new review which aimed to gather evidence from previous observational studies on whether LDL cholesterol (so-called "bad cholesterol") was linked with mortality in older adults aged over 60. The conventional view is that having high LDL cholesterol levels increases your risk of dying of cardiovascular diseases, such as heart disease.
Researchers chose 30 studies in total to analyse. 28 studies looked at the link with death from any cause. Twelve found no link between LDL and mortality, but 16 actually found that lower LDL was linked with higher mortality risk – the opposite to what was expected.
Only nine studies looked at cardiovascular mortality link specifically – seven found no link and two found the opposite link to what was expected.
However, there are many important limitations to this review. This includes the possibility that the search methods may have missed relevant studies, not looking at levels of other blood fats (e.g. total and HDL cholesterol), and the possibility that other health and lifestyle factors are influencing the link.
Most importantly, as the researchers acknowledge, these findings do not take account of statin use, which lowers cholesterol. People found to have high LDL cholesterol at the study's start may have subsequently been started on statins, which could have prevented deaths.
Funding was provided by the Western Vascular Institute. The study was published in the peer-reviewed BMJ Open and, as the journal name suggests, the article is open-access, so can be read for free.
Four of the study authors have previously written book(s) criticising "the cholesterol hypothesis". It should also be noted that nine of the authors are members of THINCS – The International Network of Cholesterol Skeptics. This is described as a group of scientists who "oppose…that animal fat and high cholesterol play a role [in heart disease]".
If you were playing Devil's Advocate, you could argue that this represents a preconceived view of the authors regarding the role of cholesterol, rather than the open, unbiased mind you would hope for in the spirit of scientific enquiry. That said, many important scientific breakthroughs happened due to the efforts of individuals who challenged a prevailing orthodoxy of thinking.
In general, the UK media provided fairly balanced reporting, presenting both sides of the argument – supporting the findings, but with critical views from other experts.
The headlines are based on a new review which aimed to gather evidence from previous observational studies on whether LDL cholesterol (so-called "bad cholesterol") was linked with mortality in older adults aged over 60. The conventional view is that having high LDL cholesterol levels increases your risk of dying of cardiovascular diseases, such as heart disease.
Researchers chose 30 studies in total to analyse. 28 studies looked at the link with death from any cause. Twelve found no link between LDL and mortality, but 16 actually found that lower LDL was linked with higher mortality risk – the opposite to what was expected.
Only nine studies looked at cardiovascular mortality link specifically – seven found no link and two found the opposite link to what was expected.
However, there are many important limitations to this review. This includes the possibility that the search methods may have missed relevant studies, not looking at levels of other blood fats (e.g. total and HDL cholesterol), and the possibility that other health and lifestyle factors are influencing the link.
Most importantly, as the researchers acknowledge, these findings do not take account of statin use, which lowers cholesterol. People found to have high LDL cholesterol at the study's start may have subsequently been started on statins, which could have prevented deaths.
Where did the story come from?
The study was carried out by researchers from the University of South Florida, the Japan Institute of Pharmacovigilance and various other international institutions in Japan, Sweden, UK, Ireland, US and Italy.Funding was provided by the Western Vascular Institute. The study was published in the peer-reviewed BMJ Open and, as the journal name suggests, the article is open-access, so can be read for free.
Four of the study authors have previously written book(s) criticising "the cholesterol hypothesis". It should also be noted that nine of the authors are members of THINCS – The International Network of Cholesterol Skeptics. This is described as a group of scientists who "oppose…that animal fat and high cholesterol play a role [in heart disease]".
If you were playing Devil's Advocate, you could argue that this represents a preconceived view of the authors regarding the role of cholesterol, rather than the open, unbiased mind you would hope for in the spirit of scientific enquiry. That said, many important scientific breakthroughs happened due to the efforts of individuals who challenged a prevailing orthodoxy of thinking.
In general, the UK media provided fairly balanced reporting, presenting both sides of the argument – supporting the findings, but with critical views from other experts.
Read the complete article here.