Sunday, April 14, 2013

Saturated Fat and Cholesterol DO NOT Cause Heart Disease

On October 5, 2011, The Week reported that Denmark was the first country to create a “fat tax,” which adds a tax to foods that are more than 2.3 percent saturated fat (by weight). Above this point, customers will be charged the equivalent of $1.29 per pound of saturated fat. This tax attempts to increase average life expectancy for Danes by three years over a ten year period by reducing deaths from coronary heart disease (CHD) and cancer. 

I honestly believe that the Danish government has the best of intentions for its citizens with the passage of this law. Unfortunately, they are using the controversial Diet-Heart Hypothesis to guide their decision. This theory tries to argue that dietary saturated fat and cholesterol cause CHD. While this theory has been treated as fact for several decades, (1) it is not very well supported. (2,3)

The Lipid and Diet-Heart Hypotheses
There are actually two different hypotheses that finger cholesterol as causing heart disease: The Lipid Hypothesis and the Diet-Heart Hypothesis. The Lipid Hypothesis posits that high blood cholesterol levels cause heart disease. This theory got its start in 1918, when Nikolai Anitschkow induced human-like arthrosclerosis in rabbits fed massive amounts of cholesterol. (4,5) While Anitschkow linked blood cholesterol levels to heart disease, he didn’t believe that the cholesterol found in a normal human diet would affect blood cholesterol levels enough to produce the same result. (4) He also never linked dietary saturated fats to blood cholesterol levels.

Then, in 1953, Ancel Keys linked the Lipid Hypothesis with his Diet-Heart Hypothesis, which argued that dietary fats (later, specifically saturated fat) and cholesterol would raise blood cholesterol. Keys supported his theory with data gathered from his Seven Countries Study that showed a clear line between fat intake and heart disease in the following countries: US, Canada, Australia, England and Wales, Italy, and Japan.

Slam dunk, right? The United Sates eats the most saturated fat and suffers from the most heart disease, while Japan eats the least saturated fat and suffers from the least heart disease. Not quite. Unfortunately for Keys and his Diet-Heart Hypothesis, his study actually collected data on 22 countries. Because the data from these remaining 15 countries didn’t support his theory very well, he simply threw them out. (6) If you put the data from all 22 countries back together, then the earlier clear line between fat intake and heart disease becomes non-existent.

I won’t get into the debunking of the Diet-Heart Hypothesis very much because the theory has been more competently dismantled hereherehere, and here. But, to quickly show you how shaky the original Heart-Diet Hypothesis data was, look at the two graphs below:

The one on the left is how Keys neatly “proved” that the more fat a person eats, the higher their likelihood of dying from heart disease. However, once you include the data from all the countries that Keys collected (the graph on the right), then you get a much less clear cut cause and effect.

For example, people in Italy (#12), Israel (#11),  Mexico (#14), and Finland (#7) each got roughly 20 percent of their calories from fat. However, Italy had an average of about two deaths from heart disease, while Finland had about seven, Israel had about four, and Mexico had about one. How is that possible? If fat intake is directly connected to heart disease, then Italy, Israel, Mexico, and Finland should suffer from similar heart disease rates.

Does Saturated Fat Cause Heart Disease?
Interestingly, Keys originally believed that all fats caused heart disease, not just saturated fats (notice that the graphs above do not single out saturated fat). (7) This distinction was made official in 1984, when the National Institutes of Health held a consensus conference. (8) The conclusion of the resulting report stated:
“…we are persuaded that the blood cholesterol level of most Americans is undesirably high, in large part because of our high dietary intake of calories, saturated fat, and cholesterol. In countries with diets lower in these constituents, blood cholesterol levels are lower, and coronary heart disease is less common. There is no doubt that appropriate changes in our diet will reduce blood cholesterol levels. Epidemiologic data and over a dozen clinical trials allow us to predict with reasonable assurance that such a measure will afford significant protection against coronary heart disease.”
In this statement, we are told that there is quite a bit of evidence that justifies the reduction of foods that are high in either saturated fat or cholesterol, and that doing so will reduce our odds of getting heart disease. Unfortunately, as far as eating saturated fat and cholesterol are concerned, this statement is just not very well supported. In fact, the Diet-Heart Hypothesis has been controversial ever since its inception and has been recently debunked by several critics (Ravnskov (2), Taubes (6), Colpo (9), Masterjohn (10), Stanton (11, 12), Guyenet (3, 13))

But the most damning evidence against the Diet-Heart Hypothesis is that it has NEVER actually been confirmed by clinical trials. (9) This is an interesting observation considering that the idea that dietary saturated fat and elevated blood levels of "bad" cholesterol are the primary cause of heart disease is generally accepted as a fact by most health advocates for the last 30 years. (14,15,16)

Real World Examples of Healthy People Who are Free of Heart Disease and Eat Saturated Fat
In the 1920s, Weston A. Price, a dentist and dental researcher, searched the world looking for healthy humans. His plan was to go to several different countries and compare the “primitive,” non-industrial cultures from each location to their industrial (Westernized) counterparts. Everywhere he went (SwitzerlandScotlandCanadaNorth Americathe Pacific IslandsPolynesiaAfricaAustraliaNew Zealand, and Peru) he found that the non-industrial cultures—who only ate their traditional foods, which often included high saturated fat intake—had perfect dental arches, minimal tooth decay, good immunity to infectious diseases, no incidence of heart disease, and were found to be in excellent overall health. These cultures ate varying degrees of naturally-raised meat, wild-caught seafood, pastured raw dairy, and fresh fruits and vegetables.

Cultures introduced to modernized foods (e.g., white flour, sugar, refined vegetable oils, canned goods) had signs of physical degeneration that included tooth decay, deformed jaw structures, crooked teeth, arthritis, and improper immune function.

Price chronicled his findings in exceptional detail in his book Nutrition and Physical Degeneration (which is available for free online). There are quite a few pictures in this book that quickly draw the reader’s attention to how destructive the Western diet can be. Below is a picture of two brothers (you can read about them here). The younger brother (left) “insisted on having white bread, jam, highly sweetened coffee and also sweet chocolates,” while the older brother (right) enjoyed “primitive food of oatmeal and oatcake and sea foods with some limited [raw] dairy products.” (17) Which brother do you think enjoyed better health?

More recently, Staffan Lindeberg studied the Kitavans, a non-industrial culture in Papua New Guinea. (18) On his web site, he says:
“During an inventory in 1989, we found what appears to be one of the last populations on Earth with dietary habits matching what would have been the case for the population of Homo sapiens in their original habitats on the island of Kitava, one of the Trobriand Islands in Papua New Guinea's archipelago.”
It was observed that the Kitavans lived exclusively on root vegetables (yam, sweet potato, taro, tapioca), fruit (banana, papaya, pineapple, mango, guava, water melon, pumpkin), vegetables, fish, and coconuts. Western foods (e.g., edible fats, dairy products, sugar, cereals, and alcohol) contributed to less than 0.2 percent of their calorie intake. Also, because of their coconut consumption, saturated fat equaled almost 90 percent of their total daily fat intake (and their total fat intake was 21% of total calories). (19)

Here is a 100-year-old man from Kitiva.
After being thoroughly studied, the Kitivans were observed to have no indications of stroke, diabetes, dementia, high blood pressure, or congestive heart failure; no problems with body weight (actually, their BMI is pretty low); and no acne. And this is in spite of a nearly universal love of cigarettes.

Will this Law Extend the Life Expectancy of Danes?
So what have we learned? Since scientists have never been able to connect saturated fat consumption or healthy blood cholesterol levels to heart disease, and we have evidence of heart disease-free, non-industrial humans who consume a diet high in saturated fat, it seems very unlikely that a reduction of dietary saturated fat consumption will increase longevity for Danes.

And what does all this mean for you? It means that you can relax about the saturated fat that you are eating every day. Enjoy your animal meats, butter, and coconut oil. These foods are delicious, healthy, and will not give you a heart attack (actually, it will likely prevent it).

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