Health Effects of Partially Hydrogenated Fats and Trans-fatty Acids and Their Prevalence in Foods

Abstract

This paper provides both research and practical consumer information on partially hydrogenated fats (PHF) and trans-fatty acids (trans-fats). A literature review of peer-reviewed journals, as well as public health websites, was conducted in order to provide an understanding of the health effects of consuming foods containing PHF and trans-fatty acids. The literature review also explains what PHF and trans-fatty acids are and why they are commonly used in certain types of food. Additionally, research was conducted at a local grocery store to examine food labels of margarine products, prepared snack foods, and frozen meals and appetizers. The purpose of this research was to obtain information about the percentage of these foods that contain PHF or trans-fatty acids. The paper is followed by the author’s personal examination of the consumption of trans-fatty acids and PHF.

Introduction

This research paper seeks to draw conclusions on partially hydrogenated fats (PHF) and trans-fatty acids in prepared foods and the health effects of consuming these types of fats. A literature review examines the epidemiological findings of various studies reporting on the common health effects of consuming PHF and trans-fatty acids along with an explanation of why these types of fats are used in many foods. The research was conducted at a local grocery store to understand what types of foods containing PHF and trans-fatty acids are commonly available for consumption by buyers.

Types of Fats in Foods

Good and bad fats. Fat content in food has been a contested issue over the past two decades. The four main types of fats have been categorized as “good” and “bad” fats based on their health risks and benefits (The Truth About Fats, 2007). The “good” fats include monounsaturated fats and polyunsaturated fats. Both of these fats contain one double bond in their chemical makeup, making them easily digestible. Monounsaturated fats are found in foods such as olive and canola oils, peanut and almond butters, most nuts, and some seeds. Polyunsaturated fats are found in vegetable and seed oils, walnuts, some seeds, fish, seaweed, leafy greens, and soybeans. Specifically, the heart-healthy Omega-3’s and Omega-6’s are found in polyunsaturated fats. These types of fat have many health benefits including lowering low-density lipoprotein (LDL) cholesterol and triglycerides, preventing abnormal heart rhythms, building and strengthening cell membranes, reducing inflammation, and preventing heart disease (The Truth About Fats, 2007). Monounsaturated and polyunsaturated fats are also known to increase HDL levels, which in combination with lower LDL levels, create a healthy lipoprotein profile and healthier heart function.

Saturated fats and trans-fatty acids are considered “bad” fats. These fats have more complex chemical makeup and are therefore more difficult for the body to break down and digest. These fats have a number of deleterious health effects which will be discussed later in this paper. Saturated fats are found in butter, whole milk, cheese, and red meat. Trans-fatty acids or PHF naturally occur in small amounts in some meats and dairy products but are mainly found in packaged products. It is estimated that PHF are in up to 40% of foods on grocery store shelves (Trans Fats: The Science and Risks, 2014). Trans-fatty acids and PHF are typically found in processed snack foods such as crackers and chips; baked goods such as muffins and cakes; fast food, specifically fried foods; and margarine and shortening products (Fats, 2013). They can also be found in frozen pizza and other frozen meals and appetizers, coffee creamer, ready-to-use frosting, salad dressings, some breakfast cereals, and refrigerated dough products such as biscuits and cinnamon rolls (Food, 2013). While both saturated and trans-fats are considered unhealthy, numerous studies have shown that PHF are actually worse than saturated fats for dietary and cardiac health, and therefore should be completely eliminated from the diet (Fats, 2013). Many foods that appear healthy based on the name or marketing actually contain PHF, therefore ingredient labels should always be consulted before consumption.

Production of PHF. While PHF and trans-fatty acids naturally occur in some meats and dairy products, the majority of trans-fats in foods come from artificially produced PHF. These are created by adding hydrogen to liquid oils in order to turn them into solid fats (Trans Fat, 2012). This process is called “hydrogenation,” and PHF are the main type of trans-fatty acid consumed in the United States and Canada (Food, 2013). Despite the similarity of name, fully or completely hydrogenated oil does not contain trans-fatty acids. However, if a food label refers to “hydrogenated vegetable oil,” it most likely contains some trans-fatty acid (Diseases and Conditions, 2014). In an effort to continue to sell products with trans-fats even as consumers try to limit their intake of these fats, food producers use a variety of names for PHF in order to continue to use these without consumer knowledge. Trans-fats can be hidden under the ingredients of margarine or shortening. Additionally, foods that do not appear to have trans-fats, including many fast food options, are high in PHF and have the same negative effects as foods with PHF on the ingredient labels.

Use of PHF. Trans-fats were developed during the backlash against saturated fats. Saturated fats such as animal fat, butter, and full-fat dairy products were known to clog arteries, so trans-fats were developed the hydrogenation process to counter this stigma (Trans Fats: The Science and Risks, 2014). Unfortunately, trans-fats turned out to be far less healthy than saturated fats, but benefits had been discovered by food manufacturers. Trans-fats were noted to last longer than butter without spoiling. In addition to giving food longer shelf life, trans-fats improved flavor stability and created a less greasy feel in foods than saturated fats (Diseases and Conditions, 2014). Trans-fats also ensured that foods were easier and cheaper to produce, thereby providing a major benefit to food manufacturers (Diseases and Conditions, 2014).

Adverse Health Effects of PHF and Trans-Fatty Acid Consumption

Saturated fats gained notoriety as contributing to heart disease and high cholesterol levels during the 1990s. Ascherio et al. (1999) suggest that the adverse health effects of PHF are even stronger than those of saturated fat, and they estimate that replacing PHF with unsaturated or polyunsaturated fats would prevent over 100,000 premature deaths due to cardiovascular disease.

Numerous epidemiological studies have shown that the consumption of PHF has many negative effects on health, notably in terms of heart disease, stroke, and type 2 diabetes (Trans Fats, 2013). Compared with non-hydrogenated soybean and palm oil, partially hydrogenated palm and soybean oils adversely alter the lipoprotein profile (Vega-Lopez et al., 2003). PHFs increase LDL or “bad” cholesterol and triglycerides, two of the main risk factors for heart disease. While scientists do not know specifically why hydrogenation has these effects, it is thought that adding hydrogen to oil makes the oils harder for the body to digest (Diseases and Conditions, 2014). Specifically, PHFs increase plasma concentrations in LDL cholesterol (Mauger et al., 2003). In addition to raising LDL levels, PHFs are known to lower high-density lipoprotein (HDL) or “good” cholesterol, increase inflammation, and cause endothelial dysfunction (Mozzaffarin, Aro, & Willett, 2009). The combination of raising LDL and lowering HDL is a dangerous combination for the lipoprotein profile and heart health in general. To counter the risk of coronary heart disease, it is recommended that PHFs be replaced with vegetable oils or tropical oils such as coconut or palm (Mozzaffarian & Clark, 2009). While tropical oils have somewhat of a bad reputation for heart health, they are still less harmful than trans-fats.

PHF and trans-fatty acids also have negative effects on numerous other functions in the body. In addition to adversely affecting plasma lipids and lipoprotein profile, trans-fats increase the fractional and endogenous synthesis rate of free cholesterol. This means that they increase the breakdown of muscle protein (Sundram, French, & Clandinin, 2003). Additionally, high LDL levels and low HDL levels are known to increase the risk of ischaemic heart disease, or restriction of blood supply to body tissues, and cardiac arrhythmia (Stender & Dyerberg, 2004). The ratio between HDL and LDL is important to monitor, as the lower the ratio, the greater the risk of numerous heart problems.

PHF and trans-fats also negatively affect non-cardiac functions. Stender and Dyerberg (2004) studied health in Europe as lifestyles became more Westernized, including increases in the trans-fat intake. They discovered positive associations between trans-fatty acid intake and breast cancer, cancer of the large intestine, asthma, atopic (allergy hypersensitivity) disorders, and hay fever. Despite the negative health effects of saturated fats, increases in allergies and asthma were not associated with increased intake of these types of fats.

Regulation

As the negative health effects of PHF and trans-fats became more and more apparent, a number of regulations and recommendations were made about these products. On November 12, 1999, the U.S. Food and Drug Administration (FDA) announced a proposal to include trans-fats on the ingredient lists of all foods so as to increase awareness of PHF consumption (Ascherio et al., 1999), and this was later implemented in 2006 (Mozaffarian et al., 2006). Canada’s Food and Consumer Product division responded that they were aware of the regulations, and Vice-President Susan Abel commented

Canada once had the highest levels of trans-fat consumption in the world. Today, the majority of Canada’s food supply is trans-fat free and Canadians have access to thousands of reformulated products. In fact, according to Health Canada’s own monitoring program, 80 percent of the pre-packaged foods have reached the voluntary target reduction goals (CBC News, 2013).

After the 2015 Canadian Community Health Survey on nutrition intake, Health Canada will further assess what needs to change in product ingredients and labeling.

It is recommended that consumers limit trans-fat intake to less than one percent of daily total calories (Trans Fats, 2013). Based on the naturally occurring trans-fats in some foods, this recommendation effectively leaves no room for artificially manufactured trans-fats. However, despite the regulation efforts, trans-fats can still be hidden in foods. If a product contains less than 0.5 grams of trans-fats per serving, the food producer can list the food as having 0 grams of trans-fats on the label (Ascherio et al., 1999). Based solely on the gram count of trans-fats on labels, a consumer could intake numerous foods that have less than 0.5 grams of trans-fats which would add up to a few grams daily without knowing that he or she was consuming any trans-fats. Additionally, while most people have heard that trans-fats are unhealthy, many people do not know that partially hydrogenated oils or fats are the same things as trans-fats. Because of this, it is important to review the ingredient list for PHF rather than rely solely on the upper portion of the nutrition label.

Materials and Methods

For the purposes of this research, two major local grocery stores, Walmart and Independent at the south end of town, were visited. Food products were randomly selected and certain ingredients were recorded. As various names are used for PHF and trans-fatty acids on ingredient labels, the following ingredients were recorded: hydrogenated oils, partially hydrogenated oils, modified oils and fats, and hydrogenated vegetable fats.

The margarine examined included Imperial, PC Blue Celeb, and Becel.

The frozen appetizers and meals examined included Delissio garlic bread, Delissio Rising Crust pizza, McCain French fries, McCain pocket pizzas and frozen pizzas, Pinty’s Pub Caesar wings, Swanson frozen meals, Healthy Choice Steamers, Amy’s Kitchen pot pies, Amy’s Kitchen burritos, Amy’s Kitchen macaroni and cheese, Casa di Mama pizzas, and Bluewater Sea frozen fish meals.

The candy bars examined included Wunderbar, Snickers, Twix Bars, Kinder, Caramilk, Mr. Big, Scaero, Cadbury Crème Eggs, Rolos, and Nielson Jersey Milk Bites.

The snack foods examined included Pepperidge Farm cookies, Triscuit crackers, Ritz Crackerfuls, Annie’s Cheddar Bunnies, Special K cracker chips, Vital almond oat bran cookie, Nabisco Rice Thins, Goldfish crackers, Chips Ahoy cookies, Crispers crackers, HandiSnacks, Christie Bacon Dipper crackers, Nabisco Wheat Thins, Breton crackers, Pop-Tarts, Keebler Pretzel Bites with peanut butter and white fudge, Twistos crackers, and Ritz original crackers.

This portion of research also involved calling one of the margarine companies to inquire about the company’s reasoning for using trans-fatty acids in their products. PC Blue Celeb margarine was chosen to contact regarding the use of trans-fats in products.

Results

The margarine products and frozen foods studied contained the greatest percentage of PHF and trans-fatty acids. Each margarine product contained PHF under the names partially hydrogenated soybean oil and hydrogenated cottonseed oil. PC Blue Celeb customer service department was contacted to gain further understanding of the PHFs used in the margarine. The customer service representative explained that “modified oil” is an umbrella term for oils or fats that have been changed from their original content through hydrogenating, adding saturated fats, or changing the chemical makeup of the fat molecules. Modified oil means that the oil may or may not be hydrogenated. The customer service representative also explained that hydrogenated or modified oils help maintain product shelf life and create longer-lasting products once a consumer purchases the product. The representative did not answer questions about the health effects PHF and trans-fatty acids but rather redirected the discussion back to the fact that the products last a long time without going bad. It can be assumed that margarine companies want to steer attention away from the unhealthy effects of trans-fats as doing so causes them a major loss of business and revenue.

Two-thirds of the frozen meals and appetizers researched at the grocery store contained trans-fatty acids and PHF. Casa di Mama, Delissio garlic bread and rising crust pizzas, and Swanson frozen meals contained partially hydrogenated soybean oil. The McCain products including French fries, pizza pockets, and frozen pizzas, as well as the Bluewater Seafood meals, contained hydrogenated vegetable fat. The other four frozen foods studied included Pinty’s Pub Caesar wings; Amy’s Kitchen pot pies, burritos, and macaroni and cheese; and Healthy Choice Steamers. These products did not contain PHF and instead used butter and olive, canola, soybean, safflower, and sunflower oils. In general, the manufacturers that advertise as “healthy” used mono- or poly-unsaturated or saturated fats rather than PHF. However, consumers should not make decisions based on these marketing tactics alone and should instead consult the ingredient lists.

Only 40% of the chocolate candy bars studied contained PHF and trans-fatty acids. Snickers contained partially hydrogenated soybean oil; Cadbury Wunderbar contained partially hydrogenated palm and corn oils; Caramilk contained partially hydrogenated palm kernel oil; and Cadbury Crème Eggs contained modified palm oil. The other six candy bars studied contained milk fats, palm oil, coconut oil, and butter.

The snack foods contained a surprisingly low percentage of PHF and trans-fatty acids. Of the 18 products studied, only five contained PHFs. Triscuit crackers, Chips Ahoy cookies, Keebler Pretzel Bites, Ritz original crackers, and Ritz Crackerfuls contained hydrogenated vegetable oil. The other 14 products contained various other fats including vegetable oil, sunflower oil, peanut oil, and canola oil.

Discussion

Existing literature shows that PHF and trans-fatty acids have a number of deleterious health effects, most notably on cardiac health. The research conducted shows that the foods that contain the greatest amount of PHFs are frozen meals and appetizers, fried foods, and margarine products. Based on this, it is recommended that consumers limit the intake of these specific foods as well as pay attention to other snack foods that may contain PHF and trans-fatty acids. Based on the measures taken by the FDA and other regulatory agencies, it is safe to assume that PHF and trans-fatty acids should be generally avoided in order to ensure cardiac health.

Specifically, margarine can be replaced with butter or other forms of fat in cooking and baking. If frozen meals are necessary, some brands such as Amy’s Kitchen and some Healthy Choice offer products that are free from PHF. Snacks should be chosen based on whether or not they contain PHF and trans-fatty acids, and fresh produce is always a healthier option than packaged snack foods.

It is recommended that consumers make the following changes in diet in order to eliminate or reduce their consumption of trans-fats. Replace margarine or shortening with butter, or eliminate the use of these products completely. Do not rely solely on the upper portion of nutrition labels, as small amounts of trans-fats that are not listed can add up over multiple consumptions. Do not be fooled by marketing that claims that products are “natural” or “heart-healthy” as these terms are not regulated and therefore do not necessarily correlate to the ingredients or processing methods. Instead, read ingredient labels and do not consume products that contain partially hydrogenated oils or fats, hydrogenated oil, modified oils or fats, margarine, or shortening. Limit the consumption of fried foods or ask that foods be cooked in non-hydrogenated vegetable oil. If restaurants cannot accommodate special requests, it is recommended that consumers either choose other menu options or frequent other restaurants that do not use PHFs.

The most effective way to avoid consumption of trans-fats is to create a diet consisting mainly of fresh foods such as fruits, vegetables, fresh lean meats such as fish and chicken, and non-processed grains. While PHFs are in many foods available for purchase at grocery stores, research and discretion can result in choosing a dietary lifestyle that greatly limits the intake of trans-fats.

Conclusion

Between the adverse health effects studied and the research conducted on the number of foods in grocery stores that contain trans-fats, it is clear that despite regulations enacted to protect consumers from trans-fats, there is still a wide selection of products that contain trans-fats. In the grocery store research conducted for this paper, nearly half of the products studied contained some form of trans-fats. This number is higher than the estimation of 40% of products noted earlier in this paper (Trans Fats: The Science and Risks, 2014), however, this research did not take into account fresh produce, which would have lowered the percentage. Despite the efforts of the FDA to warn consumers against the major cardiac risks that exist from the consumption of trans-fats, food producers are finding loopholes to hide trans-fats in their products through creative labeling and marketing.

Acknowledgments

I would like to thank my professor for the assistance given with this project. I would also like to thank the employees of the Food Basics grocery store in Sudsbury for assisting me with the in-store portion of my research.

References

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Diseases and Conditions. (2014). Trans Fat: Avoid this Cholesterol Double Whammy. Retrieved February 25, 2014, from http://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/trans-fat/art-20046114.

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Sundram, K., French, M. A., & Clandinin, M. T. (2003). Exchanging partially hydrogenated fat for palmitic acid in the diet increases ldl-cholesterol and endogenous cholesterol synthesis in normocholesterolemic women. European Journal of Nutrition, 42(4), 188-194.

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Appendix: Personal Intake of PHF

In a typical week, my food intake mostly comes from fast-food restaurants. I just have cereal and fruit for breakfast most days, but on weekends I sometimes go out for pancakes or waffles and scrambled eggs. For lunch and dinner, I generally eat out. I frequent chain fast-food restaurants such as Kentucky Fried Chicken, McDonald’s, Domino’s Pizza, Pizza Hut, and Red Lobster. I usually consume fried chicken, burgers, pizza, French fries, biscuits, and similar foods. I love chocolate, and I snack on chocolate bars such as Snickers, Kinder, and Twix candy bars. My usual beverages are Coca Cola or Red Bull.

My breakfast of cereal and fruit contains no PHF, but when I go out for breakfast, I assume that the pancakes and waffles are made with vegetable oil. My lunches and dinners all contain trans-fatty acids or PHF as I typically consume fried foods during these meals. On average, I estimate that between two-thirds and three-quarters of my food intake contains PHF or trans-fatty acids.

After performing research on PHF and trans-fatty acids, I am reconsidering my diet. I consume a lot of PHF and trans-fatty acids. I realize that this is likely to have a negative effect on my health in the long run in the form of high cholesterol, coronary heart disease, allergies, or type 2 diabetes. Ideally, I would eliminate fried foods and packaged snacks from my diet and replace these with fruits, vegetables, whole grains, and lean meats. Another healthy choice for me would be to eat out less and pack my own lunches and dinners out of foods that I bought based on studying ingredients and nutrition labels.

Realistically, I will still probably eat out a lot as my busy schedule makes it difficult to grocery shop and prepare meals at home. In order to change my diet, I can eat at fast-food restaurants less often or choose foods from the menus that are not fried. I have noticed that many fast-food restaurants have grilled chicken sandwiches, salads, and fruit options. I can try to incorporate snacks that do not have PHF and cut down on the amount of Snickers bars I eat, as these are a source of PHF and trans-fatty acids where other candy bars are not.

I realize that because I value my health, I need to incorporate different foods into my diet and eliminate some of the foods that contain large amounts of PHF. While I do not believe it is realistic to completely change my diet, I realize that a few small changes can make a difference. I believe that if I can incorporate one change at a time, I could have a vastly different diet in a year or two. I will start by being aware of the types of foods I order at fast-food restaurants and incorporating a piece of fruit into my diet as a snack to replace a candy bar once per day.