The Cholesterol Hypothesis
The cholesterol hypothesis is the prevailing theory on why human beings develop heart disease. It goes something like this; elevated total cholesterol and, especially, elevated LDL cholesterol, is the primary cause of atherosclerosis and cardiovascular disease. Further, replacing saturated fat in the diet with vegetable oils lowers serum cholesterol and, therefore, lowers cardiovascular disease risk. This information is decades old and has become medical dogma. Unfortunately, it’s not true.
Much of this information comes from the Seven Countries Study originating in the 1950s, although data is still analyzed today to glean more knowledge from it. It tied fat consumption to heart disease. The lead author, Ancel Keys, found the more fat a society consumed the higher the rate of heart attacks. It seemed to be very convincing evidence. This observation helped shape health policies for governments and the medical field. In fact, to some degree, it still does today.
Missing or Unpublished Data
There was a problem with it, though. Data showed that there were populations of people who consumed lots of fat but had low heart attack rates. Conversely, there was data showing there were populations of people who consumed very little fat but had high rates of heart attacks. This information was omitted from the study. The study also failed to account for the fact that the people who consumed the most fat were also most likely to consume the most sugar. While nutrition science is notoriously difficult, these seem like variables that shouldn’t have been ignored.
Superimpose the above inconsistencies with interventional studies conducted in the same time period and you’ll quickly see you’ve been misled. Ancel Keys’ study was an observational study. This means he observed a connection between two sets of data. Observational studies cannot prove cause and effect. For example, imagine this headline; “New science has observed a connection between high heel wearing and breast cancer.” Does wearing high heels cause breast cancer? Of course not. It just happens that people who wear high heels (mostly women) also develop the majority of breast cancer. This silly example shows just how easily an observational study can get it wrong.
The gold standard for proving cause and effect is an interventional study where populations are randomized and given either an experimental intervention or are controls, generally receiving a placebo. In dietary trials, placebos are difficult, if not impossible, to give so participants diets are often left unchanged for the control population.
The Sydney Diet Heart Study and the Minnesota Coronary Experiment
Around the same time that Ancel Keys was doing his work, two interventional studies were conducted. One was called the Sydney Diet Heart Study and the other the Minnesota Coronary Experiment. Both of these studies were incompletely published (data was missing) or went completely unpublished for reasons no one really knows. It is likely because they contradicted accepted dogma and scientific journals were hesitant to put their reputations on the line for something they viewed with skepticism. We know about them now because a group of researchers recently uncovered the unpublished data, reanalyzed it with modern methods and found some shocking results. The reanalysis of both studies was published in the British Medical Journal.
In both of these experiments, totaling about 10,000 participants, saturated fat was removed from the diets of the experimental group and replaced with vegetable oils. This is precisely what the American Heart Association says you should do. What did they find? They found that by removing saturated fat, the participants’ cholesterol went down. This is not unexpected. What they didn’t expect to find was that in both studies the low saturated fat group experienced more cardiovascular disease, more coronary heart disease, and an increase in all-cause mortality.
So let’s summarize; Removing saturated fat and replacing it with vegetable oils lowers cholesterol. But lowering cholesterol raised the risk of heart disease? Yes. This puts an enormous, truck-sized hole in the cholesterol hypothesis. In fact, in the Minnesota Coronary Experiment for every 30 points a person’s cholesterol dropped their risk of death increased by 22%.
This information is counter to everything nutrition science says. Three other randomized controlled trials have confirmed the results. Couple this with another very recent study evaluating over 68,000 elderly people which found an inverse relationship in those over 60 between LDL level and mortality, and I think we seriously need to evaluate the cholesterol hypothesis.
The Real Cause of Heart Disease
If cholesterol doesn’t cause heart disease, what does? It’s quite simple actually – endothelial damage. The endothelia are the cells that line your blood vessels. There are things that are known to damage this lining – high blood pressure, inflammation, high blood sugar, smoking, oxidative stress, and aging. These triggers, and pursuant damage, set into motion a cascading set of events that allows your immune system (in the form of white blood cells) to infiltrate the lining of the vessels. Only after they do this do they begin the process of engulfing cholesterol, which eventually leads to arterial plaque formation. Control those triggers and you will never develop heart disease. If you do not control those processes, it doesn’t matter how low your cholesterol is. You will still develop heart disease. I hear you saying, “But how do I control aging?” That is more difficult as we will all age, but living a healthy lifestyle helps with all of those factors, including aging. Plus, aging alone is unlikely to be a significant cause of heart disease.
It’s important to recognize that cholesterol is not your enemy. Sedentary lifestyle, smoking, a diet high in refined food, the excess consumptions of sugar, and poor stress management are much more serious concerns. Lowering cholesterol for the sake of lowering it has no beneficial effect on your heart. As a matter of fact, the research shows it could be downright dangerous for it. So if you’ve been told you have high cholesterol and that lowering it will lower your risk, you might want to consider the information above and seek an alternative.