Eating the Right Fats for Health, Part One

[This article, and the two that will follow, originally appeared in Equilibrium, an alternative newspaper that is no longer in business.]

Part One: Introduction to Lipids

Back in the middle 1990s, the woman I was seeing at the time decided to join the corporate gym provided by her employer. Her trainer put her on an ultra low-fat diet, with the ideal being zero fat consumption. Because we were living together, it seemed the best way I could support her was to do the diet with her.

We did the diet for three months. During that time we both lost a considerable amount of weight--some fat, but also a lot of muscle due to insufficient protein. We ended up being fat skinny people, like Jared in the Subway commercials. During those three months, however, we experienced a variety of strange symptoms whose origin we could not identify.

We both suffered from dry skin and hair, brittle nails, mental sluggishness, low energy, sore joints, and a complete loss of sex drive. We had no idea what was happening to us. It took me many years to learn the cause of our strange symptoms: we weren't eating enough fat.

The extremely low-fat diets of the past are no longer seen as useful for general weight loss, and we are beginning to understand in more detail that lipids (fats) are crucial to our health and well-being. In fact, we now know which fats are good for us and which ones can cause diabetes, cancer, arthritis, and arteriosclerosis. We know that certain fats are crucial in the development of the fetus and newborn, while an excess of others can retard intellectual development.

Before we go any further, however, let's dispel one of the most persistent health myths: dietary intake of cholesterol does not result in high blood serum cholesterol. Contrary to what the food industry would have you believe, the amount of cholesterol in the diet has only a very small impact on serum cholesterol levels, in the range of 2 to 3 percent. The primary sources of high blood serum cholesterol are saturated fat (animal fat) and trans-fatty acids (shortening and hydrogenated oils--processed fats that are solid at room temperature). The worst part of the false labeling about no- or low-cholesterol foods being "heart-healthy" is that these are very often the foods that are loaded with trans-fatty acids. Trans-fatty acids pose a serious health risk, especially for heart disease, and I'll talk more about this dangerous form of fat in the next installment in this series.

Structures and Functions of Lipids

Scientists refer to the family of fats as lipids, and this includes cholesterol, even though it isn't technically a fat. Lipids are composed of 12 to 20 carbon molecules. Lipids with no double bonds between the carbons are called saturated because each carbon has as many hydrogen molecules attached as is possible. An unsaturated fat has at least one double-bonded pair of carbons (monounsaturated), or more (polyunsaturated), with as many as six double bonds possible (DHA).

The last carbon in the chain is called the omega carbon. If the first double-bonded carbon pair occurs three carbons from the omega, it is called an omega-3 fatty acid. If the first double bond occurs six carbons from the omega, it is an omega-6 fatty acid, and the same pattern holds for the omega-9 fatty acids.

The human body cannot produce its own alpha-linolenic acid (omega-3) or linoleic acid (omega-6), which is why these are often referred to as essential fatty acids (EFAs). The healthy human body can produce all the other fatty acids it needs from these two essential lipids. Unfortunately, there are a variety of factors that can prevent the necessary conversions.

Types of Fats

Linoleic acid (omega-6): sunflower, sesame, corn, safflower oils.
GLA: Gamma-linolenic acid (omega-6): primrose, borage, black current seed oils.
Arachidonic acid (omega-6): animal fat, milk fat, eggs, squid, fish.
Alpha-linolenic acid (omega-3): flax, canola, pumpkin, hemp seeds, walnuts.
EPA (omega-3): cold water fish.
DHA (omega-3): cold water fish, deep sea algae.
Oleic acid (omega-9): most seeds, nuts, green leafy plants, olive and flax oils.
Saturated Fat (n/a): animal fat, some tropical oils (palm and coconut).
Trans-fatty acids (omega-3 & -6): hydrogenated oils, highly heated oils, some animal fats.

Lipids are crucial in the proper function of every living cell. If you could open every cell in the body, lay each cell's membrane flat, side by side, you could cover 10 football fields. From the air, it would look like an enormous oil slick. The fats we eat determine the health status of these membranes. Trans-fatty acids, for example, make these membranes stiff and rigid, rather than soft and flexible, and this affects the health and function of the cell.

Fatty acids also are vital for the healthy formation and function of myelin, the protective covering of nerve cells. Nearly 75 percent of myelin is composed of fatty acids. Because these fats are acquired from the foods we eat, too little fat, unhealthy fats, or a poor balance of fats can compromise the function of our nerve cells, causing messages to be sluggish, misdirected, or sent in error. Evidence suggests that treatment with fatty acids can alleviate the symptoms of some nerve cell based diseases, such as MS.

Since we are talking about nerve function, did you know that the seat of nerve function, the brain, is 60 percent fat? Doctors used to believe that diet had little impact on brain function, but now we know that dietary lipids have a profound effect on brain function, especially in infants and children. Proper fatty acid consumption, especially from the omega-3 family, is crucial for brain size, brain cell growth, and learning capabilities; deficiencies in the diet can create problems in all three areas.

Prostaglandins

When a cell is activated to transmit information, fatty acids are released that are quickly transformed into hormone-like substances which can produce a variety of profound effects on functions throughout the body and brain. These substances (first discovered in the prostate gland) are called prostaglandins. There are three important prostaglandin series with which we need to be concerned: PGE1, PGE2, and PGE3.

PGE1 is formed from linoleic acid (omega-6). It is anti-inflammatory and immune system enhancing. Research has shown the PGE1 pathway to be important in depression, MS, ADHD (attention deficit hyperactivity disorder), schizophrenia, and PMS-related mood changes. For many of us, this prostaglandin is important because it can reduce the pain and swelling of arthritis.

PGE2 is highly inflammatory and is formed from arachidonic acid. PGE2 can cause swelling, a lower pain threshold, and higher blood viscosity (thicker blood that clots quicker). Arachidonic acid can also produce leukrotrienes, substances that are 1,000 to 10,000 times more inflammatory than histamine, the substance associated with allergies and colds. PGE2 is not desirable in high quantities, but it does serve a variety of purposes that contribute to overall health (for example, PGE2 contributes to blood clotting when we are cut, preventing an extreme loss of blood that could endanger our lives). Too much PGE2 production, a common result of Western diets, causes this bodily messenger to become problematic.

PGE3 is formed from EPA and DHA, omega-3 fatty acids found primarily in cold-water fish, or converted from alpha-linolenic acid. This series of prostaglandin is mildly anti-inflammatory and immune system enhancing. Its greatest benefit seems to be in its ability to counter the effects of the PGE2 series substances. EPA and DHA can also reduce arachidonic acid in the cells, which circumvents the whole problem of its conversion to PGE2.

Conclusion

From this brief introduction to lipids, I hope it is clear that fats are crucial in our diets. Further, it should be apparent that consuming the right fats while reducing the bad fats is very important to physical as well as mental health.

For most of our history as a species, we ate a diet of about 1:1 to 1:3 omega-3 fatty acids to omega-6 fatty acids. These ratios are seen as optimal for our health. The current American diet, however, is in the neighborhood of a 1:30 ratio. Some people have been tested to have a ratio of nearly 1:100. Highly processed foods, animals raised on grain instead of grasses, and depletion of soil nutrients through use of chemical fertilizers have all contributed to this horrible imbalance.

In the next two columns, I will examine the bad fats and how to minimize their consumption or reduce their negative effects on our health, and then the good fats and how to reap the benefits of the most current research into fatty acid nutrition. Proper fatty acid nutrition can alleviate a variety of health issues, from depression to arthritis, from dry, itchy skin to preventing some forms of cancer. It just takes a little knowledge and the discipline to change our diets.