In the last blog we discussed saturated fats.  We will continue to discuss fatty acids with monounsaturated fats.

II. Monounsaturated Fat

Monounsaturated fatty acids are liquids at room temperature and semisolid or solid when refrigerated.  Foods containing monounsaturated fats reduce low-density lipoprotein (LDL, the “bad”) cholesterol, while possibly increasing high-density lipoprotein (HDL, the “good”) cholesterol.

There are two types of monounsaturated fatty acids.

1. Palmioleic acid (Omega 7) is found mainly in dairy foods.

The good: Recent evidence shows that palmioleic acid reduces the incidence of heart disease since it decreases blood cholesterol.  It also lowers blood glucose levels thereby reducing the risk of type II diabetes.  Milk is also a good source of protein.

The bad: I read over and over “Only calves should drink cow’s milk.”  The negative aspects of dairy consumption are starting to out-number the positive.  Dairy products contain a lot of saturated fat if you don’t choose “fat-free” products.  Allergies and lactose intolerance are increasingly more common.  Because of consumer awareness more people are avoiding mass produced milk and selecting hormone and pesticide-free dairy products. It is proven that sebaceous glands secrete more oil after consumption of all (even fat-free) dairy products.  The response to dairy products mimics the reaction that occurs during puberty when we have increased oil production, which leads to acne.

2. Oleic acid (Omega 9) is what we commonly think of when referring to a monounsaturated fatty acid since olive oil (an omega 9) is becoming more commonly used in American food.

Various foods contain oleic acid.  The richest and most common source of oleic acid is the olive and olive oil. Avocados, canola oil, nuts and seeds all contain oleic acid in varying amounts.

The good: The beneficial health effects of olive oil are due to both its high content of monounsaturated fatty acids and its high content of antioxidative substances.  Studies have shown that olive oil offers protection against heart disease by controlling LDL cholesterol levels while raising HDL levels. Olive oil is the cornerstone of the Mediterranean diet.

The bad: There is nothing really bad about fresh olive oil.  However, olive oil can oxidize easily. Olive oil, as any other product containing antioxidants and/or oil is vulnerable to oxidation when it is exposed to light and oxygen.  It must always be stored in an airtight, dark bottle and kept in a cool environment.  Oxidized oils are dangerous to your health because they oxidize the cholesterol in your body and can also deplete our body’s antioxidant supply.  Oxidation destroys antioxidants.

When I started the omega-3 section of this blog I quickly realized I could not write about why we needed omega-3 oils if I didn’t know details about the other oils we consume.  While researching the subject I found myself wading in the minutiae of fatty acid composition.  I really did not want to learn as much as I did about this subject.  However, like anything else, the more I learned the more interested I became.  I can now say that this is a fascinating subject!

Once again, before we get into the details of omega-3 I think we should organize the fats we consume into their three main categories.

As I mentioned in a previous blog, understanding oils is confusing because there are so many names given to the different oils.  Various literature will make reference to “double bonds” and “saturated with hydrogen.”  Don’t let these descriptions and/or terminology confuse you.

Saturated, monounsaturated and polyunsaturated are three basic categories of fat. I am not including trans fat in the categorization.  As you recall, trans fats are hydrogenated omega-6 oils.  They are not considered a food group since the body cannot use them for energy.  Its only purpose is to provide a cheap source of fat in packaged and fast food.

I. Saturated Fat

Saturated Fatty Acids are chains of fatty molecules packed or saturated with hydrogen atoms.  Saturating, or packing, chains of oils with hydrogen, makes the oil very dense and stiff. They are solid at room temperature and tend to solidify inside our arteries if more than we need for cell function is consumed.

Most of the saturated fat we consume comes from animals and milk which we make into butter and cream.  Egg yolks have nearly been banned from most people’s diets since they represent the epitome of the saturated fat which causes high cholesterol in our blood.  The saturated fat in eggs doesn’t raise our cholesterol  as much as we once thought.  Eggs are also packed with nutrients and a great source of low calorie protein.

Some plant oils, such as palm, coconut, and cottonseed, also contain a large amount of saturated fat.  American companies who used these oils in popcorn and other snack foods have stopped using them since they received such bad press.  However, scientists are taking another look at palm and coconut oil since there is evidence that these plants also have nutritional value that may outweigh the negative effects of the saturated fat they contain.

The good: Saturated fat is necessary for brain function and is an integral part of a well-functioning immune system.  Saturated fat is also an important source of energy.

The bad: Saturated fat is detrimental to our health when it is the only fat we include in our diet.  The type of fat we consume should be varied since each fat serves a particular purpose.  No fat is 100% bad except trans fat.  Saturated fat can cause plaque inside our arteries, which can lead to a decreased blood flow to our heart, causing a heart attack.  However, this information is a bit misleading since in the past we have confused and interchanged the terms “saturated fat” with “trans fat.”

The inception and evolution of trans fats

In the early part of the 20^th century we started to import soybeans because they were an inexpensive source of protein.  The protein was extracted from the soybean leaving a huge surplus of soybean oil.  Soybean oil gets rancid very quickly so the food industry found a way to stabilize the liquid oil. They chemically altered unsaturated fat by hydrogenating (adding hydrogen to) the oil creating trans fats.

Everyone thought this was a great idea since:

1) We were consuming “unsaturated” fat instead of butter and lard.

2) It was very economical since it can be produced in a lab avoiding all of the time, effort, and money spent on obtaining it from animals.

3) Convenience was an issue also since margarine, made with hydrogenated soybean oil, could be spread on food as soon as it was removed from the refrigerator because it remained soft even while cold. The new fat (e.g. Crisco) became liquid when heated, which made it even better than lard for frying food.

4) The stability of this new oil solved the problem of oils becoming rancid. Inexpensive, stabile oil allowed the food companies to develop a variety of  economical packaged foods.  A lot of hydrogenated vegetable oils are used in packaged foods.

The production and consumption of trans fats steadily rose through the 20^th century.  In 1994, it was estimated that trans fats caused 20,000 deaths annually in the US from heart disease. What started as a “healthy, unsaturated fat alternative” turned out to be much worse than the saturated fat products we were trying to avoid.

In 2002 the National Academy of Science (NAS) stated that:

1)      “dietary trans fatty acids are more deleterious with respect to coronary heart disease than saturated fatty acids”

2)      “trans fatty acids are not essential and provide no known benefit to human health” whether of animal or plant origin.

The NAS goes on to say that while both saturated and trans fat increase the levels of LDL (bad) cholesterol, trans fat also lowers levels of HDL (good) cholesterol, thus increasing the risk of coronary artery disease.

Identifying trans fats on product labels should be pretty easy since the U.S. government, in January 2006, required food manufacturers to list them on the Nutrition Facts panel. Consumers now know how much of all three—saturated fat, trans fat, and cholesterol—are in the foods they choose.

Since food manufacturers had to adhere to the law, they removed most of the trans fat from their products.

Interestingly, trans fats have not disappeared from packaged foods in 2011. A label from a recently purchased box of Saltine Crackers states it has 0 trans fat. However, in the ingredient list there is “partially hydrogenated cottonseed oil,” which is bad fat. Cottonseed oil is inexpensive and naturally high in saturated fats. In this case, it is hydrogenated to further extend its shelf life.

It’s difficult but not impossible to avoid trans fats.  Since we cannot avoid every single gram of bad oil, we can consume omega-3 oil to help reverse the negative effects of bad fats.

After writing the last nutrition blog I decided to elaborate on Omega-3 fatty acids by examining and explaining the various types. What started out as “a few more details” turned into a much more complicated picture on the subject of FATS.  We need to have a general discussion about oil so we can understand why omega-3 oil is so important for our health.

While studying various sources on basic lipid (fat) chemistry and research findings on how various fats affect our tissues and organs, I now understand why so many people are confused about what to eat and what to avoid. There are a lot of different words used interchangeably that describe or label fat.  Most people have made a decision to avoid fat altogether or ignore the subject and eat whatever they choose since “everything is bad for us.”

We don’t always know what kind of fat is good or bad. However, identifying words that tell us how the fat is processed and modified will be very useful in the fat-identifying process.

We cannot avoid fat. We also need fat (saturated fat) for nerve, immune, brain, heart, and lung function. Every part of our body needs various types of fat.

However, our bodies do not need and cannot use trans fat. Trans fat is destructive in every way. Unfortunately, saturated fats (beef, butter, and cheese) have become almost synonymous with trans fat in the minds of most people.

The entire subject of fat horror stories started with the development of hydrogenated oils (trans fats).  A lot of our diseases can be attributed to the excess consumption of processed and inexpensive fast foods, which contain hydrogenated oils almost exclusively.

Trans fats are also linked to an increased incidence of diseases like diabetes, heart disease, and cancer.  As a matter of fact, since trans fats are so destructive, Congress has passed a law forcing food manufacturers to include trans fats on the labels of their products. In 2008 California took it one step further and passed a law that restaurant foods must be free of artificial trans fat.