hydrogenated oils? - Diet & Nutrition Message Board

andreeny · 07-13-2002, 10:43 AM

What are they, and why shouldn't you have them?

sean · 07-13-2002, 07:46 PM

HI Andree-

Hydrogenated and partially hydrogenated oils, or trans-fats or trans-oils as they are often known, are fats that are rarely found in nature, but are the result of adding hydrogen atoms to (saturating) long-chain fatty acids, usually the polyunsaturateds we know of as soybean oil, corn oil and the like.
this has the effect of hardening the oils somewhat so that they can serve as shortening like butter and lard did in the old days til people got frightened off these traditional, if greasy, foods.

Crisco was the one consumer product that brought hydrogenation into the american kitchen but these semi-synthetic fats are now everywhere--look at the labels on almost ANY baked goods in the super market, i'm afraid.

It comes as a surprise to most consumers to learn that the evidence linking saturated (but natural) fats from sources such as dairy or palm oils to artherosclerosis or heart morbidity and mortality is weak, or even contradictory, but the evidence in the research for the damaging effects of THESE fats, the hydrogenated vegetable oilsis persuasive.

whatever controversy there may be as to whether animal fats jurt the arteries and the heart (and yes, there is much more controb=versy over this point than yu may have heard about), NO one seems to dispute the deleterious effects of trans-fats.

so, there's what I know about it. Like sugar, this is one of those food sources ALL dieters--low carb, low cal, low fat--can agree should be cut from the diet. Zero is the best amount to consume, or as close to zero as we can get.

Hope this helps clarify.

sean

[This message has been edited by sean (edited 07-13-2002).]

justink80 · 07-13-2002, 09:26 PM

Quote:

Originally posted by sean:
HI Andree-

It comes as a surprise to most consumers to learn that the evidence linking saturated (but natural) fats from sources such as dairy or palm oils to artherosclerosis or heart morbidity and mortality is weak, or even contradictory, but the evidence in the research for the damaging effects of THESE fats, the hydrogenated vegetable oilsis persuasive...

The evidence is hardly weak.

Vegetarians and Vegans have less than one-half the risk of heart disease as the general population. For every 1% decrease in blood cholesterol levels, heart disease risk decreases by 2-4%. Vegans have as much as 35% lower cholesterol levels. Cholesterol levels increase due to consumption of saturated fat and cholesterol. In contrast to meat, most plants are very low in saturated fat and plants contain NO cholesterol. (Neal Barnard, "The medical costs attributable to meat consumption," Preventive Medicine, Nov. 1995, p. 646-655.)

A low-fat vegetarian diet combined with exercise and stress management has been shown to reverse heart disease. (Mark Messina and Virginia Messina, The Dietitian's Guide to Vegetarian Diets (Aspen Publishers: Maryland, 1996)

Dean Ornish, a well-known and well-regarded expert in the medical community, advocates a diet composed of 10% fat -- with no meat, no eggs, and no dairy, as well as stress management and group sessions. In a 1990 study, "Ornish and Gould first published a study showing that, after one year, 82% of patients who adhered to Ornish's regimen had arteries that showed some reversal or change in their blockages. Patients in a control group, who followed American Heart Association guidelines of a 30%-fat diet, _got_worse_."

There exist cases upon cases of people who had extremely diseased and weak hearts and arteries, and upon following Ornish's (vegan) diet, many symptons disappeared, sometimes within one month. In particular, as detailed in one of his books, a man named Victor Karpenko opted for Ornish's regimen after being informed he would need bypass surgery. Within one month, his chest pains disappeared, and in the following years, he could exercise regularly, including mountain hikes and using the stairmaster.

Ken McDough, medical director at the Mutual of Omaha insurance company, learned of Ornish's program and began considering it as an economic alternative to surgery. (Bypass procedures cost about $50,000; Ornish's program would cost about $5,000-$6,000). The insurance company ran a pilot program, and found that bypass surgery and angioplasty was avoided in 75% to 80% of cases.

I don't consider the evidence weak in any sense of the word.

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They worship neither a god nor even a demon, but a dead man. -- Celsus

justink80 · 07-14-2002, 02:25 PM

Can anything truly be "proven"?

Jon Wynne Tyson points of the various differences between ourselves and carnivores. Carnivores have a short bowel to permit the expulsion of toxins; vegetarians have long bowels to allow for slow digestion and fermentation. Carnivores have long sharp teeth and retractable claws and their jaws open straight up and down, unlike vegetarians whose jaws can move in a circular motion for slow mastication. Humans, as well as other vegetarian mammals, sweat through the skin while carnivores keep cool by rapid breathing and extrusion of the tongue.

Evolutionary biologists continue to unearth fossil evidence which indicates that early man, and the hominids which preceded him, were mainly vegetarians but who would eat meat when plant-based food was scarce. It is even theorized that early man actually made a decision to abstain from eating meat.

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They worship neither a god nor even a demon, but a dead man. -- Celsus

arkie6 · 07-14-2002, 09:28 PM

Quote:

Originally posted by andreeny:
What are they, and why shouldn't you have them?

Hydrogenated oils are typically found in margarine, shortening, deep fried foods, and most baked goods on your grocers shelves (breads, cookies, cakes, etc.)

Food manufacturers take liquid vegetable oil like soybean or cottonseed oil and subject it to hydrogen gas, high pressure and temperature, and a nickel catalyst to turn the liquid oil into something that resembles natural saturated fats (mostly solid at room temperature). This thicker texture is needed for baked goods and other processed foods. Plus, the hydrogenation process makes the unstable vegetable oils less likely to oxidize and become rancid. It's a plus for food manufacturers since vegetable oils are cheaper than natural saturated fats and the hydrogenation process extends the shelf life of many processed foods by making them less likely to spoil and become stale.

For consumers though, hydrogenation can have negative health consequences. The problem with hydrogenated vegetable oils is the trans fatty acids that are formed during the chemical process. These fats (primarily elaidic acid [(E)-9-octadecenoic acid or trans-D9-C18:1]) were totally foreign to human nutrition prior to the advent of hydrogenated vegetable oils in the early 1900's. These trans fats, just like all other fats you consume, are incorporated into nearly every cell in your body. The problem with trans fats is that they just don't fit right due to their altered structure (trans configuration vs. natural cis configuration of unsaturated vegetable oils).

Experimental evidence shows that trans fats can increase LDL cholesterol and lipoprotein-a (important risk indicator for Coronary Heart Disease - CHD) and reduce HDL. The carefully performed metabolic study of Mensink and Katan (NEJM 1990; 323: 439-45) found that trans fatty acids behave unlike any other type of fat as they raise LDL and depress HDL. The negative impact of trans fats on the total cholesterol/HDL ratio was almost twice as great as that of saturated fat. Several studies have confirmed that trans fats are worse than saturated fats with respect to total/HDL ratio. In the now famous Nurses Health Study, the women with the highest intakes of trans fatty acids had a 50% higher risk of CHD than women with low intakes of trans fats and there was a highly significant dose response relationship.

Lichtenstein et al (NEJM June 24, 1999) has confirmed the finding of others that there is lowering of Lp(a), the lipoprotein associated with increased risk of development of cardiovascular disease, by saturated fat and the raising of Lp(a) by trans fatty acids. This study was conducted using a number of soybean oil sources including soybean oil shortening containing 9.9 grams of trans fatty acids per 100 grams of fat, whereas most of the soybean oil shortenings used in cakes, cookies, crackers, and donuts, as well as in deep fat frying, in the US contain between 35 and 50 grams of trans fatty acids per 100 grams of fat. The stick margarine used for the study contained 20.1 grams of trans fatty acids per 100 grams of fat, whereas some of the popular stick margarines contain more than 30 grams of trans fatty acids per 100 grams of fat. All of the soybean oil diets lowered HDL cholesterol levels. Thus the findings of adverse effects from consumption of the trans fatty acids were seen in diets potentially lower in trans than it is possible for some people to be consuming.

Ascherio et al (NEJM June 24, 1999) has reviewed the trans fatty acid and coronary heart disease research and conclude with several points including the fact that "...studies indicate an adverse effect of trans fatty acids on the risk of coronary heart disease...and that the adverse effect of trans fatty acids appears to be stronger than that of saturated fatty acids."

Alan