To me, fats is the most confusing topic I have taken on. Many experts believe that in our collective quest years ago to go "low fat", our population started eating more refined carbohydrates (especially sugar), driving at least some of the current obesity epidemic. But as the pendulum swings back the other direction, there are lots of opinions about types and amounts of fats in our diets.
For simplicity's sake, this post will focus on trans fats. In the next posts, I will address unsaturated fats, including omega-3 and omega-6 fatty acids, and saturated fats.
Fat Basics
Before we dive into trans fats, a quick overview of the types of fatty acids:
Very simply, the main component of a fatty acid is a chain of carbon atoms. These chains can be as long as 24 carbons or as short as 6.
Saturated Fatty Acids--In saturated fatty acids, there are only single bonds between each carbon atom. Because of this, saturated fatty acids can stack on top of each other like planks of wood and are usually solid or firm at room temperature (for example, butter). Naturally occurring saturated fatty acids are found in animal-derived foods, like beef, milk, and eggs (fat is milk is considered solid, just suspended in the watery whey).
Unsaturated Fatty Acids--For these fatty acids, some carbons are joined by double bonds. This makes the unsaturated fatty acids more bendy, meaning these fatty acids are more likely to be liquid at room temperature (for example, olive oil). Monounsaturated and polyunsaturated just referred to the number of double bonds (mono=one, poly=2 or more).
Hydrogenated Fatty Acids--Unsaturated fatty acids can be unstable (hence the advice, for example, to store olive oil is a cool, dark place) and are not solid at room temperature. To solve this dilemma, food scientists take an oil that contains a lot of polyunsaturated fatty acids (for example, soybean oil) and force hydrogen through it. This converts some or all of the double carbon bonds to single bonds.
If all of the double bonds are gone, the oil is fully hydrogenated (or simply hydrogenated) and has become at saturated fatty acid. If some of the double bonds remain, these fatty acids are partially hydrogenated and contain trans fatty acids, a term used to describe the location of the hydrogens. The key point here is that artificial trans fatty acids act more like saturated fatty acids. Additionally, there is evidence to suggest that artificial trans fatty acids should be particularly avoided as trans fat get you two ways: both increasing your bad cholesterol (LDL) AND decreasing your good cholesterol (HDL).
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| So many choices--Read the label! |
Natural trans fatty acids do occur in products from cows and other ruminants (for example, beef and milk). This trans fatty acid, conjugated linoleic acid (CLA), is not thought to be harmful and some research suggests may be beneficial.
It is important to note that many foods are a mix of saturated and unsaturated fats. For example, while saturated fat is the predominant type of fat in butter, it also contains monounsaturated and polyunsaturated fatty acids.
Trans Fats
Frankly, I hadn't really been paying much attention to trans fats over the last couple of years, thinking I needed to focus more on increasing unsaturated fats in our eating. Plus, I naively thought that manufacturers must have gotten rid of most trans fats...not quite the case.
The current thinking is that artificial trans fatty acids should be avoided completely so the less in your diet, the better.
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| Some of my husband's favorite foods may need to be rethought |
Where do you find trans fat? Any item with partially hydrogenated oil. Many store-bought bakery items and fried foods contain trans fats. Other items include refrigerated dough, margarine, and non-dairy creamer (which Marion Nestle calls "white sweet liquid margarine") and candy bars.
The key is to read two parts of the label:
Nutrition Facts panel--In the Total Fat section of the Nutrition Facts panel, there is a listing for trans fat. Ideally, you want to select items with zero grams of trans fat. However, this panel only tells part of the story. If a food has less than 0.5 grams of trans fat per serving, it can be listed as "0 grams trans fat". So multiple servings may mean a significant intake of trans fat.
Ingredients listing--This is where the rubber meets the road. If an item has partially hydrogenated oil (often soybean oil, but others as well), it contains trans fat even if the label reads "0 grams trans fat". For example, my husband's beloved Pillsbury ready-to-bake cinnamon rolls list "0 trans fat", yet the ingredient listing includes partially hydrogenated oil, meaning there is trans fat in our breakfast treats.
Avoiding Trans Fats
Living in DC, I knew that Montgomery County had banned trans fats in restaurants. However, I did not realize that this is actually rare, with MoCo being one of the few places to do so. Whole Foods Market's policy is not sell any products containing partially hydrogenated oils.
The FDA is considering revoking GRAS ("generally recognized as safe") status for partially hydrogenated oils. This has been in the works for awhile and, with any food regulation, I am hopeful, but I think there are no guarantees where Big Food is concerned. If partially hydrogenated oils are not GRAS, it would be illegal to sell any product containing them. Keep your fingers crossed!
Crisco
Back to good ol' Crisco. Arriving at Giant, I am greeted with front package labeling stating "0g Trans Fat per serving". Flipping the package over, however, I discover partially hydrogenated oil as one of the ingredients. Again, the serving size allows Crisco to claim 0 grams of trans fat.
This Crisco is reformulated from what my mom used which surely was a trans fat bomb. The new (2007) formula contains "less partially hydrogenated cottonseed and soybean oils and more fully hydrogenated cottonseed oil — which contains no trans fat." However, the partially hydrogenated oil is still present, just under the radar.
As companies responded to the freak out over trans fat, they looked for other options for solid fats like Crisco. However, these options are more expensive and likely increase the saturated fat content. While I will focus on saturated fat in another post, it is important to note that saturated fat should be limited to 10% of daily calories (or closer to 7% for decreasing heart disease risk) For a 2,000 calorie diet, 7% comes to 140 calories or just under 16 grams of saturated fat (fat is 9 calories per gram).
Adding fully hydrogenated oils is one option for companies. Many margarine-type products are created by mixing fully hydrogenated oils with liquid unhydrogenated oils until the mix spreads like butter. Another option, which Crisco employs, is to use palm oil. Palm oil is solid at room temperature because of its saturated fat content. And while the focus of this blog doesn't include environmental concerns, I feel compelled to note that palm oil harvesting leads to deforestation.
Icing Choices
For a quick comparison, I looked at Crisco as compared to two tubs of icing. All serving sizes are 3 Tablespoons.
While the Betty Crocker frosting lists 0 grams of trans fat, it contains partially hydrogenated soybean and cottonseed oil. For this comparison, I assumed their 2 Tablespoon serving contained 0.4 grams of trans fat.
I made the same assumption for Crisco which lists 0 grams per one tablespoon (0.4 x 3 = 1.2 grams). I realize that homemade frosting would be more than just Crisco, but as the predominant ingredient, I feel this is a fair comparison.
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Trans fat
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Saturated Fat
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Crisco
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1.2 grams
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9 grams
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Betty Crocker Whipped Chocolate Frosting
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0.6 grams
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3.75 grams
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Duncan Hines Whipped Fluffy White Frosting
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2 grams
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2.75 grams
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Basically, for these products and many others, your choice is trans fat or saturated fat (or both). However, I won't be ditching my tub of Betty Crocker for homemade Crisco frosting, given Crico's high saturated fat content and Betty Crocker's likely lower trans fat content.
I think it is important to remember these items are treats, limited to a few birthdays a year. As I look more closely at the products we buy, my focus will not be a complete elimination of trans fat, but a greater reduction. When we eat out or our girls have a birthday cupcake at school, we are likely consuming some trans fats. Since those out-of-home activities are not going to stop, eliminating or greatly reducing trans fats at home is important to achieve the needed balance.
References
All quotes and sources are linked in the above text. General nutrition information came from Whitney and Rolfes' Understanding Nutrition, 13th ed., from Nutrition for Sport and Exercise, 2nd ed. by Dunford and Doyle, and from Marion Nestlé's What to Eat.
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