The Truth Behind Trans Fat

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The nutrition world is consistently changing; one year it is recommended we all switch from butter to margarine, then a year later we hear that margarine is much worse than its natural counterpart, butter. With all these confusing messages, it is not surprising that many people are confused.

Primer on Fats

All fats have the same basic structure; they are a chain of carbon atoms with varying amounts of hydrogen atoms attached to each carbon. This is important to understand the next piece to this article. Let’s delve into some simplified chemistry:

Think of the structure of fats as a school bus; the bus itself is the carbon atom chain discussed above and all the seats are the hydrogen atoms.

• Saturated Fat: all the carbon atoms are full of hydrogen atoms, the “seats on the bus” are full. No other atoms can fit onto the structure because there are no “empty seats.” Saturated fats are easy to identify because they are solid at room temperature (butter, shortening, animal fats, etc).
• Monounsaturated fat: (mono, meaning one) fats: there is one “empty seat” on the bus and the rest are full. There is room to fit more hydrogen because of the one “empty seat.” Monounsaturated fats are liquid at room temperature (vegetable oils, like olive oil, canola oil, etc).
• Polyunsaturated (poly, meaning many) fat: several of the “seats” are empty. Polyunsaturated fats are also liquid at room temperature (flax oil, fish oil, etc).

Trans Fats

Trans fats are basically vegetable fats that have been changed chemically by a process known as hydrogenation. Remember the monounsaturated fats from above had one empty “seat” without a hydrogen atom. The process of hydrogenation or partial hydrogenation is when food manufacturers artificially add hydrogen to unsaturated fats to provide greater stability and, ultimately, longer shelf life; hydrogenation makes liquid fats solid at room temperature.

The advantage is that the fat generally has a longer shelf life, or in the case like crackers, gives them a crisper texture. It's a product that's been used in food manufacturing for quite some time.

Downside to Trans Fats

The problem is that the body treats the hydrogenated fat like it's a saturated fat. Trans fats have adverse actions on lipid profiles since they raise LDL, the “bad” cholesterol that contributes to plaque formation, and decrease HDL, the “good” cholesterol, which offers defense against artery clogging fats. Trans fats also negatively affect plasma markers of inflammation and reduce endothelial function, which are all subsequently associated with an increased cardiovascular disease risk (1) . Similar results have been realized not only for those with preexisting heart disease but they also occur in healthy individuals (2). This is particularly important for individuals with diabetes; since folks with diabetes already have an elevated risk of cardiovascular disease, precautions need to be taken to ensure all controllable aspects of health are practiced (e.g., reducing trans fats in the diet, increasing physical activity, etc).

Table 1: Select foods that commonly (not always) contain trans fats

Most baked goods Margarines Crackers Cookies Shortening Cereal Breads Pastries Breadcrumbs Pie crusts Cakes Non-natural peanut butter French fries

Therefore, with these negative health outcomes clearly correlated to trans fats, it is important to discuss specific foods they may be found in (Table 1), suggested intakes, how to avoid them, and the new labeling laws that will require trans fat be listed on food labels. These tips may help provide insight into the world of trans fats. Is there a suggested intake for trans fats? There is no suggested intake for trans fats. However, it is suggested that intakes are lowered as much as possible since there is no requirement for trans fats in the diet.

How can someone tell if a product contains trans fats?

The simplest way is to read the ingredient panel; if hydrogenated or partially hydrogenated oils are listed, it contains some trans fats. In 2006 it will be mandatory for all food manufacturers to list trans fat on their product’s nutrition facts panel. This will be listed on a separate line, under saturated fat.

How can the ingredient list say hydrogenated or partially hydrogenated, but list 0 grams of trans fat?

Some products may contain low amounts of trans fats, but still list zero trans fats on the food label. Remember, if the ingredient list says hydrogenated or partially hydrogenated oils, the food contains trans fats. Food manufacturers are allowed to list the amount of trans fats as zero, if, and only if, each serving contains less than 0.5 grams of trans fat. Keep in mind that this is per serving, so if it’s normal to sit down with a container of non-natural peanut butter on your lap and eat it by the spoonful, the normally low amount of trans fats in each serving will quickly add up. Of course the calories will too, so this practice is not recommended at all.

Table 2

Sample List of Trans fat Free Margarines Benecol Brummel and Brown Fleischmann's Original, Unsalted, Light and Made with Olive Oil Olivio Premium Spread Smart Balance Smart Beat Take Control

Is butter safer than margarine?

Butter is a more natural product, with only one or two ingredients (cream and salt). Traditional margarine contained trans fats, however there are now many trans fat free margarines available. Trans fat free margarines may have little to no hydrogenated oils, however they do have a grocery store list of natural and artificial ingredients to make the product flavorful and give it the yellow color. If a very small amount is used on foods or cooking, there should be no concern, however people should evaluate why they are using it and if there is a healthier substitute such as natural peanut butter when needing a spread for bread. For cooking, olive oil or canola oil may be better choices.

Are the trans fat free margarines recommended for people with diabetes?

Margarine is made from vegetable oil, is low in saturated fat and has no dietary cholesterol. Trans fat free margarines replace the otherwise high amounts of hydrogenated oil with other ingredients that are necessary to act as thickening agents, or emulsifiers. Here is a brief list of the more common additions:

• Mono- and diglycerides are types of fats that act as emulsifiers and stabilizers in margarines, but only compromise a very small percentage of the overall product (typically less than 0.5%).
• Soy lecithin is also used in margarines. As the name suggest, soy lecithin is derived from the soybean itself and appears to be 100% safe for consumption. It is typically included in both organic and non-organic margarines.
• Potassium sorbate is included in many non-organic products as a preservative (anti-fungis and anti-molding). There are no scientific studies suggesting its use is unhealthy for individuals, particularly in the very low doses used in manufacturing margarines.
• Beta carotene: this is used to add the yellow color to margarines and butter sprays. This is commonly consumed in the diet, so there is no safety concerns with adding it to these products.
• Sterols and stanols are included in some newer margarines (e.g., Benecol, Take Control). These ingredients block the absorption of cholesterol, making these spreads healthier alternatives to regular margarine and butter. These products appear to be effective without negative side effects with regular consumption.

What is the best type of trans fat margarine to choose (stick, soft spread, or spray)?

Trans fat free tub and squeeze margarines and spreads are likely to be lower in fat, saturated fat, and trans fatty acids than stick margarines or butter itself. Stick margarines usually contain more trans fat to maintain stability-avoid those like the plague. The benefit of trans fat free sprays, like Olivio’s new buttery spray formula, is that you will use much less than a spread to provide the same flavor, meaning you’ll save even more fat and calories than if you used a spread. Of course spray margarines would not work in baking, so in this case, it is recommended to use a soft spread margarine in a tub.

The moral of the story is that trans fat free margarines are safe when consumed in small amounts. While there are more healthful alternatives, like natural peanut butter as a spread, or olive or canola oils when cooking, certain products require butter or margarine (e.g., baking). Therefore, it is best to limit the intake to only trans fat free products and only use them when necessary.

1. Lopez-Garcia, E., Schulze, M. B., Meigs, J. B., Manson, J. E., Rifai, N., Stampfer, M. J., et al. (2005). Consumption of trans fatty acids is related to plasma biomarkers of inflammation and endothelial dysfunction. J Nutr, 135(3), 562-566.
2. Mozaffarian, D., Rimm, E. B., King, I. B., Lawler, R. L., McDonald, G. B., & Levy, W. C. (2004). trans fatty acids and systemic inflammation in heart failure. Am J Clin Nutr, 80(6), 1521-1525.

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