Oils Oils, Fats & Health

Oils, called "Fats" in scientific and nutritional literature, are both essential to health and dangerous to health, depending on quantity, type, and which body of "experts" you chose to listen to. Outlined here are "currently accepted medical opinion" and some strenuous exceptions taken by medical researchers of differing stripes.

The material herein is gathered from sometimes controversial literature openly available to the public and is not intended as medical advice in any way.

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©2006 Clove Garden

Contents

Introduction

Welcome to the wonderful wacky world of nutritional science, where all sides on any issue justifiably point to the others as "junk science" supported by faulty studies and distorted by commercial interests, and where today's "medical knowledge" is tomorrow's snake oil. All sides in any heated health controversy are likely right in part and wrong in part, but since this is America, and big money and politics are involved, the truth shall not be known.

We will start out with the "science" that is pretty much agreed upon by all sides in the oils vs. health battles, then move into the controversy.
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Fats & the Body

Fats are found in all the cells of the body as energy storage, as a structural component of cell walls, and are the transport for a number of essential vitamins (known as "fat soluble vitamins") through the body. Fats also play a very important part in regulating the level and types of cholesterol in the bloodstream, which in turn affect various hormones and general health.

A diet deficient in fat will result in itchy, flaky skin and other problems, but a diet that deficient takes real determination to achieve since fats are found not only in animal products but in grains, nuts, beans and just about anything else considered edible.

A diet with too much fat, and especially too much of the wrong kind of fat, presents a high risk of heart attack, stroke, obesity, diabetes and certain types of cancer, and may make you appear ugly and undesirable to many people, possibly resulting in employment and emotional problems. On the flip side, "supermodel thin" is pretty ugly and unhealthy too.
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Fats & Cholesterol

Cholesterol is essential for health and key to production of certain hormones, including estrogen and testosterone, and in production of bile essential for digestion. The two major varieties are low density lipoprotein - LDL (bad cholesterol), and high density lipoprotein - HDL (good cholesterol). LDL tends to build up on the inside of arteries as "plaque", resulting in heart attacks and stroke.

"Dietary cholesterol" is cholesterol consumed in food, and it only comes from animal foods. Most people are not particularly sensitive to the amount of dietary cholesterol they consume because all their "blood cholesterol" is manufactured in the body, but some people are sensitive to dietary cholesterol so it is included in nutritional labeling.

Cholesterol level is important because excessive blood cholesterol, particularly LDL, can deposit on the inside of arteries as "plaque", possibly resulting in heart attack and/or stroke (blood flow blockage in the brain).

The amount and type of fats consumed are thought by many medical researchers to affect both the level and type of cholesterol in the bloodstream. Since heart, arteries and brain are often considered important parts of the body, it follows that what type and quantity of fats you consume is important. Unfortunately, this is where agreement among experts breaks down completely.
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Types of Fats

Fats are a mixture of "fatty acids", which fall into several categories each of which has an impact on cholesterol and general health. The nature of, and healthfulness of a particular fat or oil depends on the proportion among the fatty acids it is composed of. Our Oil Composition Chart provides an overview of the composition of many common oils.

  • Saturated Fats come primarily from animal sources, including butter and milk. Vegetable oils all have some saturated fats but way less than animals - except coconut and palm oil have levels way higher than animal fats - but more on that later. Saturated fats are solid at room temperature (butter, lard, etc), important for baked goods, and are highly resistant to rancidity. Conventional "medical knowledge" holds that they are the "great evil" that increases levels of LDL (bad) cholesterol in the blood.

  • Monounsaturated Fats (Omega-9) are found primarily in vegetable oils. particularly in olive oil and canola oil. They are liquid at room temperature, are reasonably resistant to rancidity, and are thought to reduce levels of LDL (bad) cholesterol in the blood, and may even help remove some cholesterol deposits from the arteries. Some studies have shown a reduction in colon cancer. All sides currently seem to agree that monounsaturated fats are a "good thing" though some say they should not be used at frying temperatures.

  • Polyunsaturated Fats (Omega-6) are also found primarily in vegetable oils, particularly sunflower oil and cottonseed oil. These fats may affect cholesterol similarly to monounsaturates, but these oils go rancid much more easily. A major controversy is whether rancidity occurs during cooking (all agree rancidity is very bad).

    Omega-3 is another polyunsaturated fat but quite different from Omega-6 in its positive effect on health. Omega-3 is found particularly in fish oils and to some extent in vegetable oils, particularly canola oil, flaxseed oil and soy oil. Vegetable Omega-3 is considered inferior because it includes just one types of Omega-3. Omega-3 fatty acids are essential to growth, reproductive system and vision and may help prevent cancer.

  • Trans Fats are found in small amounts in animal fats, but are particularly present in partially hydrogenated vegetable oil (margarine, vegetable shortening). Trans fats are now the "Greater Evil" and considered worse than Saturated Fats. They have been found not only to increase LDL (bad) cholesterol, but to reduce HDL (good) cholesterol, promote type 2 diabetes, cause brain damage and other ills, and to block conversion of vegetable Omega-3 into the usable (fish oil) types. All sides now agree trans fats are bad, but don't agree on just how bad.


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The Saturated Fat Controversy

"Accepted Medical Knowledge" holds these things to be true.

  • Saturated fat is very bad so avoid all animal fats and tropical oils (coconut, palm, palm kernel). These cause buildup of LDL (bad) cholesterol in the blood and clog the arteries.
  • Monounsaturated fats are good and should account for the majority of your fat consumption.
  • Polyunsaturated fats are probably as good for you as monounsaturated fats.
  • Trans fats are probably not a whole lot worse than saturated fats.
  • Total Fat consumption should be reduced to less than 30% of the daily caloric intake.

This viewpoint is promoted by the American Heart Association (O11) and has the full financial backing of giant grain and oil seed traders (Cargill Inc. and Archer Daniels Midland Inc.) and the food processing industry, all of whom are happy to finance as much "research" and political pressure as needed to back the health claims in their advertising.

One side effect of the industry campaign against saturated fats is a spectacular increase in trans fats consumed in the American diet - fats that all sides now agree are very bad for you. No safe limits have been established but the FDA (Food and Drug Administration) says to consume "as little as possible".

This doctrine, sometimes called the "Lipid Hypothesis", despite its popularity and support even from the U.S. Congress (as if Congress critters knew anything about nutrition), has some spectacular weaknesses which threaten to expose it as hocum and snake oil.

  • Prior to the 1920s the American diet practically reeked with saturated animal fats (even margarine was made from animal fats in those days). Vegetable oils were little used, but despite all this, heart disease and cancer were almost unknown.
  • Various ethnic groups around the world eat diets extremely high in animal fats yet show low levels of heart disease.
  • Other cultures use coconut oil for all their cooking and every meal. Coconut oil is way higher in saturated fats than even lard (92% vs. 44%) yet these people show low rates of heart disease.
  • The wildly popular Atkins diet totally violates the principles of the "lipid hypothesis" yet dieters are not dropping like flies from congestive heart disease, nor are they likely to show high blood cholesterol levels.
  • Key studies upon which this "knowledge" is based have been shown to be "bad science", irrelevant, badly misinterpreted, or all of the above (O10, O5).

Opponents of the accepted viewpoint have suggested a more persuasive case can be made that these diseases start to appear when a population adopts large quantities of refined carbohydrates such as sugar and white flour (also darlings of the grain traders and food processors) and large amounts of vegetable oils and shortenings.

In the United States, Crisco, the first partially hydrogenated vegetable shortening was invented in 1911 and became popular, promoted as a "healthier alternative", during the 1920s, about the same time heart disease and cancer started being significant killers. This is not to say Crisco was the cause or that there weren't other factors, but it certainly wasn't saturated fats causing the problem.

One group particularly vocal against the "accepted knowledge" has been the tropical oils partisans who maintain coconut oil is the most healthy cooking oil you can use even though it's about 92% saturated fat. Palm oil is lower in saturated fat and higher in monounsaturated fats with a composition profile very similar to lard and tallow.

The American Heart Association is dead set against tropical oils claiming their saturated fat will clog your arteries, but once again, ethnic populations making heavy and daily use of these oils show no arterial clogging, in fact quite the opposite. Further, the only formal research condemning coconut oil is invalid because it used hydrogenated oils (O12).
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Trans Fats (No Longer Controversial)

Trans fats are a major component of "partially hydrogenated vegetable oil", an industrial product the aim of which is to convert liquid oils into fats that are solid at room temperature and resistant to rancidity just as saturated fats are.

All sides of the fats controversy have come to the conclusion that trans fats are bad for you (O4, O2). Just how bad depends on how much of your income depends on them. Apologists say they are no more artery clogging than saturated fats which are the only other group of solid fats. Others say they are worse and point out that trans fats may also contribute strongly to other diseases, particularly diabetes and brain damage (O3).

Nonetheless, trans fats are not going away quickly because they are a darling of the fast food industry in particular and the food processing industry in general, for good (to them) reasons.

Health advocates brought intense pressure against the fast food industry for its heavy use of beef fat, particularly for deep frying. Since beef fat is high in saturated fats the accepted knowledge implicated it in killing tens of thousands of Americans every year.

Responding to this pressure the fast food industry decided to move to vegetable oils but quickly found them unusable. Beef fat is very durable at high temperatures and resistant to rancidity. A fry tank of beef fat will work for many days. Vegetable oils, especially the lower cost ones high in polyunsaturates, degraded quickly at high temperatures and rapidly became rancid and laden with toxins. You'd have to change the oil on practically a daily basis - very expensive.

The fast food solution is to use partially hydrogenated vegetable oils, in other words, the evil trans fats. These are so resistant to heat breakdown and rancidity a tank of fry oil can be run for as much as 40 days (with topping up) before it must be discarded.

Food processors favor trans fats for similar reasons. They provide baked goods and other products with an attractive texture, and they resist rancidity resulting in a long shelf life for the products, and you can claim "0 saturated fats" on the label (O1).

Unfortunately for both industries, the FDA (Food and Drug Administration) is issuing new rules requiring trans fats be included in labeling and in nutritional information sheets. The industries must be in compliance by 1 Jan 2006, which is causing a scramble to find alternatives.

Leading the charge away from trans fats are the vegetable shortening manufacturers. Crisco in particular has come up with a formula using fully hydrogenated oils (hard as a hockey puck) whipped up with enough unhydrogenated oils to achieve an acceptable texture while maintaining a level of trans fats they are allowed to call "zero".

Of course fully hydrogenated oils are in actuality saturated fats, the very thing vegetable shortening was supposed to get you away from. Do not expect a big health campaign against these saturated fats because they are made from the very vegetable oils the grain traders are promoting in their "heart healthy" advertising to replace saturated fats with.
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Polyunsaturated Oils and Cancer

Now here we have a raging controversy pitting the full wealth of the grain traders and food processors against vocal opponents.

All sides seem to be in agreement that monounsaturated fats are pretty safe, promote arterial health and may reduce risk of cancer, but monounsaturates dominate only in olive oil, canola oil and nut oils. Polyunsaturates dominate in all other vegetable oils. Canola oil is suspected of other evils (O17) and nut oils are expensive and have a low smoke point, so that pretty much leaves olive oil.

Polyunsaturated oils are far more vulnerable to rancidity, and the products of rancidity are often free radical carcinogens (promoting cancer). Opponents of the vegetable oil industry say polyunsaturates are so vulnerable to rancidity that the heat of cooking causes them to go rancid. The vegetable oil industry, while admitting vulnerability to rancidity, says it doesn't happen in normal cooking usage, but these oils have been found completely unsuitable for restaurant deep fry use.

While studies tend to show polyunsaturated fats to promote (vs. cause) cancer growth (O6. O7), much more study needs to be done. Most of the studies so far have been small and on rats but enough evidence is accumulating to take this point seriously.

One thing that is showing up fairly strongly though is that one class of polyunsaturated oils, called Omega-3 fatty acids appears to suppress cancer. Omega-3 oils are found mainly in oily fish, flaxseed oil and canola oil (O8, O9) but the vegetable versions are different from the fish versions known to be beneficial - again more study is needed.
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