The fact is, despite all the hype about "low fat", "no fat", and "bad fat", we need fat in our diets. In fact fat plays a vital role in every cell in your body.
But there are many different kinds of fats available to us. We need to be aware of the different types, which are "good", which are "bad" and how can we tell the difference.
And here is where the controversy around dietary fat starts, because while there was a huge shift away from saturated fat in the latter half of the last century in favor of polyunsaturated fat, some fat researchers are saying that this is, in fact, one of the causes of so many of the our so-called "western diseases"... heart disease, obesity, diabetes, cancer, and others.
First, let's consider the different types of fat: saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs).
Saturated fatty acids are found mainly in animal fats and tropical oils.
In addition, our bodies make them from carbohydrates. Saturated fats are stable, meaning that they do not go rancid, even when heated for cooking.
Monounsaturated fatty acid, in the form of oleic acid, is found in olive oil, almonds, pecans, cashews, peanuts, and avocados. This fatty acid tends to be liquid at room temperature, does not go rancid easily, is quite stable and can be used for cooking.
There are two polyunsaturated fatty acids most commonly found in our food: omega-6 and omega-3. Because our bodies cannot make these, they are referred to as "essential" fatty acids and must be obtained from our food. These oils remain liquid, even when refrigerated, are highly reactive and go rancid easily (especially omega-3). These oils should not be used for cooking.
Any discussion about dietary fat must include trans fats... a man-made fat that was a boon to food processors and adisaster for the consumers of products containing it. See this page for more information about trans fats.
All fatty acids
All fats and oils are made up of a combination of the naturally occurring fatty acids. Generally butter, lard, and tallow contain about 40 - 60 percent saturated fat. Vegetable oils from northern climates contain significant amounts of polyunsaturates while vegetable oils from the tropics are highly saturated (i.e., coconut oil is 92 percent saturated).
According to Nourishing Traditions, "saturated fatty acids constitute at least 50 percent of our cell membranes, giving them necessary stiffness and integrity so they can function properly." We need SFAs for calcium to be effectively incorporated into the skeletal structure... they lower Lp(a), a substance in the blood that indicates proneness to heart disease... they enhance the immune system... the fat around the heart muscle is highly saturated; the heart draws on this reserve in times of stress.
In other words, saturated fat is NOT the evil we’ve been led to believe.
Again according to the authors of this book, saturated fat does not "clog the arteries". In fact, they say that the fat in artery blockages is about 26 percent saturated with the rest being unsaturated, with more than half being polyunsaturated.
Major changes in the last century
In the early 1900s, according to Nourishing Traditions, "...most dietary fat was either saturated or monounsaturated, primarily from butter, lard, tallows, coconut oil and small amounts of olive oil. Today, most of the fats in the diet are polyunsaturated, primarily from vegetable oils derived from soy, as well as from corn, safflower and canola."
When we look at the rise of the Western diseases in the latter part of the last century one has to question the wisdom of these major changes to our collective diet.
Did the dramatic reduction in our consumption of red meats, eggs, butter and other sources of saturated fat and the corresponding increase in the consumption of polyunsaturated fats make us healthier?
Let's look at some numbers
Between the end of World War II and the late 1960s butter consumption declined dramatically and there was a corresponding rise in margarine use. Butter consumption dropped from 8.5 pounds per person to 4 pounds during this period, while margarine increased from 4.5 pounds to 9 pounds.
Other dietary fats showed similar trends. Lard went from 13 pounds to 7, cream use was cut in half and whole milk consumption dropped dramatically.
Meanwhile, vegetable shortening increased from 9.5 pounds to 17 pounds, and salad and cooking oils from 7 pounds to 18 pounds.
What’s significant about these numbers is that it was during this period... what was deemed to be the worst decades of the heart disease "epidemic", vegetable fat consumption per capita in America doubled from 28 pounds between 1947-49 to 55 pounds in 1976, while the average consumption of all animal fat (including the fat in meat, eggs, and dairy) dropped from 84 pounds to 71.
These numbers were obtained directly from Gary Taube’s book Good Calories, Bad Calories: Fats, Carbs, and the Controversial Science of Diet and Health. Gary’s book is a fascinating read... we highly recommend it.
So we have a situation where the so-called "epidemic" of heart disease, supposedly brought on by excess consumption of saturated fats, corresponds to the dramatic increase in the so-called healthy fats found in vegetables and a significant reduction in consumption of animal fats... the"evil" saturated fats.
Is it any wonder that more and more people are confused about the whole issue of dietary fat and are looking for answers beyond the "official" policies pushed on us by governments?