Here's a letter I recently wrote trying to explain this to a lovely, healthy young lady in her 30s with a Total Cholesterol of 191 mg/dl (4.9 mmol/l), LDLc of 117 mg/dl (3.0 mmol/l), HDL 66 (1.7 mmol/l), and Triglycerides 87 (0.98 mmol/l). Her doctors response - "if you don't go on a low fat diet to get that Cholesterol down, your going to need to consider taking medicine to lower your Cholesterol". Of course since I am retired from practice I could not give her a direct recommendation on the subject but I wanted to make sure she was aware of factors that might have influenced her doctor to take this position and the controversial nature of the science backing such widespread use of Statins. Here's the letter that I wrote to her.
The Cholesterol lowering medicines called "Statins" are one of my main gripes with mainstream medical practice which I feel has been somewhat corrupted by Pharmaceutical Money. People now spend 29 billion dollars a year on Cholesterol lowering medicines. The way this happened is that some early studies showed a small benefit of the medications in middle aged men with multiple risk factors for heart attack. There has never been a randomized, controlled trial of these medications that has shown any benefit from these medications in preventing a first heart attack or extending the life of a woman. In the US most medical research is funded either by Pharmaceutical Companies (Over 80%) or by the Government where Pharmaceutical Companies by their donations to politicians have great influence. The people who write the guidelines for Statin use are often researchers who depend on Pharmaceutical money to continue their research. The Doctors called "Peer Reviewers" who decide which studies get included in major scientific journals receive handsome salaries and the money that pays those salaries comes primarily from the money received by the journals from Pharmaceutical companies for advertisements. (All major medical journals are full of Pharmaceutical advertising). I think you can begin to see the problem with conflicts of interest here. Most good, kind, hardworking doctors, most likely like yours, don't have time to read all the studies and naively believe these "influencers" (the guideline producers and Journal committees) are giving them an unbiased view. They have always been taught this and really don't have time to look at the medical studies put forth by literally 1000s of doctors opposed to widespread statin use like me. And if they did they could face sanctions, ridicule and financial lose from HMO's, colleagues, credentials committees, state medical boards and their Specialty Certifying agency all of whose ranks often include doctors getting large benefits from the pharmaceutical industry.
Doctors also have carrots for prescribing them. Many HMO's have "Criteria for Quality Care" which when doctors meet these goals they get enhanced payments from these insurance companies. One of these is often how well they are able to control the LDL Cholesterol in their patients.
I had a mixed Military and Civilian career as a Family Medicine physician until I retired in2012. While working in the civilian sector every office I ever worked in had daily free lunches provided by pharmaceutical representatives. A recent survey shows that just a free lunch can influence how likely a physician is to prescribe a medication. (Study Here)
So how do these "influencers" justify their recomendation of widespread statin use without controlled trials to back them up? They use a weak form of scientific evidence called the "Meta-analysis" https://en.wikipedia.org/wiki/Meta-analysis . These are almost always done by researchers who depend on Pharmaceutical money are can be highly influenced by which studies they decide to include in the meta-analysis. Another big influencer on these studies is that there are hundreds of statin studies done by Pharmaceutical manufacturers whose outcome they "didn't like" so the studies were never published and are thus not available to be included in the meta-analysis.
Good luck making your health choice in this matter, Your friend, Paul