Medical Diagnosis and Low Fat Diets
How did corn oil, the wiping out of infectious disease and medical diagnosis categories contribute to the “low fat diet prevents heart disease” hypothesis? Read on to find out.
The idea that a low fat diet could lower the risk of coronary heart disease came into being in the early 1900s. (Coronary heart disease (CHD) describes heart disorders in which there are blockages in the arteries leading to the heart.)
Throughout the 1920s, 30s and 40s, America had begun developing a national health policy, and new health agencies like the American Heart Association and the National Heart Institute were founded. Medicine was growing into an organized industry, and more detailed medical diagnosis classifications were being established as diagnostic equipment like the electrocardiogram (ECG) became more sophisticated.
In 1929, the International Classification of Diseases (ICD) added a new diagnosis category for heart disease and called it “Diseases of the coronary arteries, Angina pectoris” (or coronary heart disease with chest pain).
As doctors learned more about this new classification, they began using it to describe their cases involving heart disease and chest pain. The recorded cases of CHD suddenly shot up.
In 1948, the ICD added an even more detailed diagnosis category called “Arteriosclerotic Heart Disease, including coronary heart disease”, and in 1968, another classification of “acute myocardial infarction” (heart attack) was added.
Again, as doctors learned of these new classifications, they began using them almost exclusively.
In fact, between 1949 and 1968, the percentage of cases diagnosed as CHD went from 22% to 90%, while the diagnoses of other types of heart disease dropped from 78% to 10%. Again, the recorded cases of CHD shot up.
Hospitals had begun using these new diagnosis classifications as well. Between 1920 and 1930, the diagnosis of coronary heart disease at New York’s Presbyterian Hospital increased 400%. Since it is very unlikely that the actual rate of heart disease increased 400% in a single New York neighborhood, it is logical to assume the actual number of cases didn’t increase, just the diagnosis terminology that the hospital used.
Since researchers looked to the disease rate data from the ICD to determine research trends, they saw these sharp increases in the recorded cases of CHD related deaths, and became alarmed.
Corn Oil Consumption Rises
Meanwhile, in addition to better diagnosis standards, the American diet was changing. Refined corn oil and margarine consumption was on the rise. The Weston A. Price Foundation notes that
"Butter consumption was declining while the use of vegetable oils, especially oils that had been hardened to resemble butter by a process called hydrogenation, was increasing—dramatically increasing. By 1950, butter consumption had dropped from eighteen pounds per person per year to just over ten. Margarine filled in the gap, rising from about two pounds per person at the turn of the century to about eight... vegetable oil consumption had more than tripled—from just under three pounds per person per year to more than ten. Many studies today link refined vegetable oils and hydrogenated fats to heart disease."
One more factor contributed to rise of coronary death rates during this time.
Infectious Disease Victories
By 1950, infectious diseases has been almost wiped out. The average life expectancy of Americans went from 48 years in 1900 to 67 years in 1950. People were living longer, and since 95% of coronary heart disease deaths occur after the age of 55, people were now living long enough to die of CHD, and this added to the perception of a surge in CHD deaths.
These three factors converged to make it seem that a heart disease "epidemic" had been born.
Then in 1950, a scientist named Ancel Keys proposed a hypothesis that saturated fat and cholesterol caused heart disease. He based his hypothesis on a study in which he gathered data from 22 countries on what people ate and the rates of heart disease in those regions. His results showed that as saturated fat consumption rose, so did heart disease.
But he cherry picked his data. He left out data from countries in which saturated fat consumption was high but heart disease rates were low, and ignored data from other countries where fat consumption was low, but heart disease rates were high.
He wrote a book explaining his unproven "lipid hypothesis" and Time magazine put him and his book on the cover in 1961. The false idea that saturated fat caused heart disease was picked up by other media channels, and soon, war was declared on cholesterol and saturated fat and the medical community went into overdrive to get the word out about the benefits of a low fat diet.
Agencies such as the American Heart Association and the National Institutes of Health began to collect and allocate huge sums of money to combat this "epidemic" of heart disease mortality. They built multimillion dollar budgets and their reputations on the hypothesis that a low fat diet was best since "heart disease was caused by saturated fat intake and high cholesterol levels."
Repetition Makes a Lie Seem Real
There was no scientific research to prove the idea that saturated fat caused heart disease. Ancel Key's study was fatally flawed, and no other study supported the idea.
But that didn't stop the US Senate. In 1977, even without the support of sound scientific evidence, the Senate Select Committee on Nutrition and Human Needs, chaired by George McGovern published the "Dietary Goals for the United States". The report actively supported the consumption of vegetable oils and lower fat foods. Citing USDA data on fat consumption, it stated that "the overconsumption of fat, generally, and saturated fat in particular. . . have been related to six of the ten leading causes of death. . ." in the United States.
Worse, the report was written, not by a team of scientists using evidence from controlled studies, but by a young labor reporter who took his data from only one scientist, a nutritionist who believed fervently in the unproven "saturated fat causes heart disease" hypothesis.
The low fat diet is healthy idea took hold in the media and through repetition and deep financial dependence, it became fixed in the American psyche.
Get All the Facts
So listen closely the the advice you get about healthy eating and any diagnosis to lower your fat consumption and cholesterol levels. Remember that this advice is based NOT on scientific evidence, but on a rise in diagnosis categories, corn oil consumption, a report researched and written by a young labor reporter, and a illogical leap of faith.
Resources for Further Reading: