By Pamela Lee, from the February 1999 Newsletter
Fat. It's a small word with large significance. For thousands of years, fats were relatively scarce, therefore, valuable. But in our current culture of abundance, "fat" is a word we might apply to ourselves in derogatory terms. "Fat" is also that tasty, rich, oh-so-satisfying foodstuff which we hear, again and again that we should avoid, or at least limit. We've heard and read so many times how our fat intake should only be 20-30% of total caloric intake, that we might think that fat is simply bad. But it's not all bad.

Fat is a concentrated source of energy and can provide twice the caloric energy of either protein or carbohydrates. Essential fatty acids are necessary for a healthy metabolism. Fats are important transporters of fat-soluble vitamins, such as A, D, E, and K; fats are an essential component of our cell membranes. Stored body fat holds our vital organs in place and protects them from bumping around during normal activity and movement. Fatty tissue insulates our organs from external temperature variations, and even helps regulate body temperature.

Fat, used in cooking, is responsible for imparting so many delicious qualities to the food we eat—like flavor, smoothness, crisp flaky texture, or moistness.

What's so bad about fat? The most obvious answer is: too much. Too much fat leads to obesity. Americans still average closer to a 40% fat intake than the recommended 30%. But more importantly, it is becoming clear that all fat is not created equal. And the really bad fat is hydrogenated fat, often referred to as trans-fat.

Hydrogenated fat was first developed in 1905 as a cheap alternative to lard. Hydrogenation is a chemical process that transforms liquid vegetable oils into spreads that remain solid (or semi-solid) at room temperature. Hydrogenation extends the shelf life of vegetable oil and the processed products that contain it, which might, on the surface, seem like a good thing. The problem is with the way our bodies metabolize these artificially-generated trans-fats. With hydrogenation, vegetable oils are combined with hydrogen gas under pressure at high heat. Metal catalysts like nickel, zinc, or copper are used to help break some of the oils' naturally occurring carbon bonds, ending up with an artificially-created, partially-saturated fat.

Research has been repeated, and has born out, that our bodies cannot metabolize trans-fats in the same way as natural vegetable or animal fats. Though the Institute of Shortening and Edible Oils continues to balk, many serious researchers have now reached the conclusion that hydrogenated oils (trans fatty acids) can be seriously detrimental to our health.

Remember when nutritionists pushed margarine over butter? It turns out that this is one of the biggest nutritional hoaxes of our time. The most widely cited evidence has been the ongoing Harvard Nurses Study, chronicling the habits and health of 85,000 nurses. Harvard's Dr. Walter Willett's published results of this ongoing study found that women who frequently ate products containing hydrogenated fats have more than 50% higher risk of heart disease than those who rarely consume them. The more trans-fatty acid (TFA) products the nurses consumed, the higher their risk. Dr. Willett's group also has preliminary, as yet unpublished, data that the nurses who developed breast and prostrate cancer had higher intakes of TFA's.

There have been a number of other research projects that have published more findings on the effects of transfatty acids. For instance, not only do TFA's raise the "bad" type of cholesterol, Low-Density Lipoprotein (LDL), but they also lowers the "good" cholesterol, High-Density Lipoprotein (HDL), thereby increasing the risk of cardiovascular disease. Other research has shown that TFA's have detrimental effects on brain serotonin, digitalis receptors, cell membrane structure, and even bone development. So not only do TFA's contribute to heart disease, but they may also increase cancer risks, promote inflammation and accelerate tissue degeneration.

Transfats appear so harmful that their consumption should not be rationalized. Damage to one's arteries, cellular structure, and metabolism are tolls that can not reasonably be compensated by taking supplements or by merely juggling to keep one's total fat consumption below the recommended 30%.

TFA's are widespread, excuse the pun. Americans use four times as much margarine (and shortening) as butter. Supermarket shelves are stocked high with foods made with hydrogenated oils: baked goods, cookies, crackers, chips, and other salty snacks, puddings, frozen fish sticks, imitation and low-fat cheeses, chicken nuggets, Hamburger Helper and other food extenders, ready-made frostings, cake and pie crust mixtures, Bisquick, and a whole host of processed foods. Typical French-fried potatoes are around 40% TFA's. Many popular cookies and crackers range from 30-50% TFA's; donuts have 35-40% TFA's.

Some good news is that the Co-op carries two non-dairy spreads that have absolutely NO hydrogenated fat. Both are Spectrum brand; one lists canola oil as the primary ingredient, the other contains mostly soy oil. I bought the canola oil spread, to taste-test it. It seemed fine to me. The next time I make muffins or a quick bread, I'll pull the Spectrum Spread out of the freezer. If I want oil on a savory bread, or a fat to dress a baked potato, I use olive oil.

Part II:
Fats: Polyunsaturated Oils and Essential Fatty Acids
From the March 1998 Newsletter

Polyunsaturated versus Monounsaturated Oil

All natural fats are blends of monounsaturated, polyunsaturated, and saturated fats. Safflower oil is made up of about 75% polyunsaturated, 12% monounsaturated, and 9% saturated fat. Corn oil is 59 % polyunsaturated, 25% monounsaturated, and 13% saturated fat. Both are referred to as polyunsaturated fats. A few decades ago, when nutritionists first warned us to avoid or minimize our consumption of saturated fats, many Americans switched to cooking with polyunsaturated oils. But now, food experts are expressing their doubts about oils that are (mostly) polyunsaturated, such as corn, soybean, safflower, and sunflower oils.

One problem is that polyunsaturated oil becomes rancid very quickly. This can be offset, to some degree, by adding a few drops of vitamin E to the bottle when you first open it, and by storing your oil away from heat and light. Many of us switched to cooking with polyunsaturated oil because we read that it lowers total blood cholesterol. While true, this is only half the story. The problem is that polyunsaturated fats lower both bad (LDL) and good (HDL) cholesterol. There is growing consensus that lowering the good cholesterol (HDL) may actually increase the risk of heart disease.

Now, food experts are touting monounsaturated fats. Monounsaturated oils do not deplete HDL, the "good" cholesterol, and they actually reduce LDL, which causes cholesterol to be deposited in the arteries.

Monounsaturated oils also appear to be a better choice in terms of cancer risk. For years studies on animals have shown a link between polyunsaturated fats and cancer. Last year, a four-year study of 61,000 women at the Karolinska Institute in Sweden found that women who ate the most polyunsaturated fats were 20 percent more likely to develop breast cancer than those who ate the least. Experts emphasize that the fats don't cause the breast cancer, but "that they may increase the likelihood that it will spread once it's occurred. That's because they seem to spur the production of hormonelike chemicals involved in the growth and spread of cancer cells."

Monounsaturated fats now seem to be the healthiest choice amongst cooking oil. They do not cause cholesterol to accumulate and they do not easily become rancid, as do polyunsaturated oils. Though I sometimes use canola oil for baking and for making skin lotions, I use olive more than any other oil. Approximately 74% of olive oil's fatty acids are monounsaturated fats, about 10% polyunsaturated and 14% saturated. (The fatty acid percentages come from the USDA Agriculture Handbook No. 8-4, 1979.)

Populations that consume olive oil as their primary dietary fat have significantly lower rates of both heart disease and cancer than cultures that don't. Mediterranean populations consume an abundance of olive oil, yet even with an unusually high-fat diet, they have a low incidence of heart disease. A recently published analysis of the Harvard nurses study indicates that when olive oil is the primary dietary fat, even when consumed in amounts that exceed the 30% recommendation, olive oil appears to reduce the risk of breast cancer. A study at the Athens School of Public Health found that women who ate olive oil more than once a day had a 25% lower risk of breast cancer than women who ate it only once a day. Spanish researchers at the Escuela Nacional de Sanidad found that women who consumed the most olive oil were 40% less likely to develop breast cancer than those who ate the least.

Olive oil not only has a high monounsaturated fat profile, but it is also rich in antioxidants called polyphenols that seem to protect against heart disease and cancer. Olive oil is also the only significant food source of substances called "squalenes". In laboratory studies, squalenes seem to slow the growth of certain cancers.

Though I once thought I didn't like it's flavor, I've now come to love the nutty taste of a full bodied golden oil, pressed from ripe olives. Not all olive oil tastes the same. When selecting olive oil, choose bottles labeled extra virgin or virgin, indicating that they are unrefined. Refined oil labeled "pure", "light", or just plain "olive oil" have been cleaned, filtered, neutralized, bleached and deodorized with solvents such as hexane.

You'll find a wide selection of wonderful extra virgin olive oils on the Coop's new shelves. You'll also find new varieties of previously highly polyunsaturated oils, now bred to be higher in their profile of monounsaturated fats, such as Spectrums's high oleic corn and safflower oils.

Canola oil, extracted from rapeseed, is also high in monounsaturated fat. Though I do use some canola oil, olive is still my primary fat. When buying canola oil, I select only varieties labeled unrefined or organic. Typical supermarket varieties are extracted with chemical solvents or high-speed presses that generate heat, which alters the oil's fatty acid chemistry in undesirable ways and promote rancidity. If you don't care for the olive flavor in sweet baked goods, try canola oil, especially Spectrum's new Super Canola that is even higher in monounsaturated fats.

Essential Fatty Acids

Lest I leave you with the impression that all polyunsaturated fats are bad, allow me to write a just bit about essential fatty acids. The essential fatty acids (EFA's) include linoleic, linolenic, and arachidonic acids. They are all polyunsaturated fatty acids that cannot ordinarily be synthesized in the body. Sometimes the essential fatty acids are collectively termed vitamin F. We need these fatty acids for a whole host of our bodies' healthful functioning and normal growth, including the growth of blood vessels and nerves. We need them to keep our skin and tissues youthful, healthy and supple.

Linoleic acid (omega 6) is in safflower, sunflower, and corn oils. It is also in other vegetable oils, nuts, and seeds. Alpha-linolenic, an omega-3 fatty acid, is found in flax oil, canola, soybean, pumpkin and walnut oils. Other good sources of omega-3 oils are cold-water fish and egg yolks (of free-range chickens).

I've read, in a quite a number of sources, that the problem with most of our diets is that we apparently consume too high a ratio of omega-6 in comparison to omega-3 fatty acids. The problem is that the fatty acids in polyunsaturated vegetable oils (omega-6) are processed in our bodies by some of the same enzymes required to break down omega-3 fats. The typical American diet contains from 10-20 times more omega-6's (from foods ranging from mayonnaise to crackers) than omega-3's. The ideal ratio, according to many experts, should be about one to one.

Recommendations for reaching an ideal ratio include replacing oils high in omega-6 (polyunsaturated oils) with peanut, canola, or olive oils (monounsaturated oils), and increasing your consumption of fish or flaxseed oil. I've filled a pepper grinder with fresh flaxseeds and placed it on the table, next to the real salt, pepper, and the flask of my favorite olive oil.

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