Did you know there is a controversy over whether low-density cholesterol (LDL-cholesterol) actually causes heart disease or is simply a secondary effect of the true cause? I didn’t until I stumbled across an article by researchers at several Japanese universities last winter…
This research article, written by independent university researchers in Japan, examined cholesterol levels and longevity, and reported that increased blood cholesterol was correlated to a longer life span – the opposite to what we would expect if high cholesterol causes cardiovascular disease (heart attacks and strokes). This study, entitled “Towards a Paradigm Shift in Cholesterol Treatment”, is available at www.karger.com/Article/PDF/381654 if you are interested in reading it yourself.
Having studied hormones for many years, I know that our hormones are made from cholesterol. Cholesterol is also used to make bile (a fluid produced by the liver and used to digest and absorb fat), and vitamin D, and it is a component of the walls of our cells. We get cholesterol from our food, and our liver also produces it; when we eat more cholesterol our liver produces less, and when we eat less the liver makes more, attempting to keep the blood level more or less constant. Our bodies do this with many essential nutrients, like calcium, magnesium, iron, sugar, etc. storing away, pulling from storage sites or producing as necessary to maintain the blood levels our bodies need to function. This is known as “homeostasis”. Cholesterol is one of these essential molecules in our body.
As a pharmacist, I have seen many reports of studies over the years that, I believed, proved the cholesterol/heart disease theory without question. Through my professional education, I learned that high cholesterol, especially LDL-cholesterol, in the blood was a major cause of plaques that blocked arteries carrying essential blood to the heart, and that lowering cholesterol would reduce the risk of a heart attack. I counseled patients to reduce their intake of animal fat and increase their consumption of “good” polyunsaturated fats such as the omega-3 oils.
Now that I’m retired and have more time to read, and with my interest piqued by the article I stumbled across in February, I started looking more closely at the research… I was shocked at what I found!
I found articles from researchers in several areas of the world that questioned cholesterol as a cause of heart disease. In particular, a text by Uffe Ravnskov, entitled "The Cholesterol Myths", seemed to cover the controversy well, describing flaws in a number of studies that were interpreted to support the diet/cholesterol/heart disease theory. Dr. Ravnskov is a family physician, now retired, who noted that this new idea didn’t seem to agree with information he had previously read. He examined the original full version of studies used to support this idea, and found what he believed were flaws. He continued reading related research and found a number of other studies that appeared to conflict with the idea that dietary fat and cholesterol cause heart disease. He began writing articles and eventually wrote a book on his findings. The original 1998 version of the book is available free online at www.ravnskov.nu/cm/ and an updated version can be found at Amazon.com or at your local bookstore. It certainly is an interesting read.
Ravsnkov begins with discussing the original study done by Dr. Ancel Keyes in 1953 that started us into the world of low fat diets and cholesterol medications. This study used data from six countries that clearly demonstrated higher fat in the diet resulted in higher rates of heart disease. But, data were available from 22 countries at the time, and when all countries were included, the association was much less clear. Some countries with similar dietary fat to that in US actually had only 1/3 to 1/4 the rate of heart related deaths but these were not included in his assessment. It seems that he cherry-picked his countries to make a graph that best supported his idea.
Ravnskov also describes several studies of populations with high cholesterol and high fat diets that have very low heart disease rates, and populations within the same country, where the affluent are reported to have much higher rates of heart disease than the poor, but where blood cholesterol and genetics would be similar.
According to the “Scientific Method”, the basis of all scientific study, any consistent conflicting study results indicate that the original hypothesis or theory must be re-evaluated. While the “statin” cholesterol medications have been shown to reduce heart disease deaths, they have many actions in the body other than simply lowering LDL cholesterol. It appears that there is enough conflicting evidence that the benefit versus risk of these drugs should be reassessed.
Lack of physical activity, mental stress, smoking and obesity are all considered risk factors for heart disease and stroke. These factors also increase the level of cholesterol in the blood. If the blood cholesterol level is merely secondary to the actual causes of heart disease, then artificially lowering it without changing the underlying sedentary lifestyle, stress, smoking and overweight would have little effect on reducing heart disease risk. If this is the case, we need to reevaluate our focus on LDL-cholesterol, and place more importance on changing lifestyle factors that are associated with increased risk.
I am certainly not advising anyone to stop taking his or her medication, but the question is: Should we be focusing more on the factors that raise cholesterol and less on trying to lower our cholesterol numbers artificially? Statins are known to exert several beneficial mechanisms along with their cholesterol lowering effect, such as reducing inflammation and "thinning" the blood. As one reference suggests: “It may be wiser to search for the lowest effective dose instead of the dose with maximal effect on LDL-cholesterol.”
If you are taking medications for cholesterol, discuss this information with your doctor, encourage him or her to examine the evidence and discuss it with local specialists, and thoroughly review possible adverse effects of your medication to ensure you receive more benefit than risk from what you are taking. And, given the importance of increasing activity, reducing stress and quitting smoking in reducing cardiovascular risk, focus on continuing to improve your lifestyle in these areas.
By constantly questioning the status quo when new evidence comes to light, we can continually improve the quality of our healthcare.
