Trans fat
From Wikipedia, the free encyclopedia
| Types of Fats in Food |
|---|
|
| See Also |
Trans fatty acids (commonly termed trans fats) are a type of unsaturated fat (and may be monounsaturated or polyunsaturated).
Trans fats occur naturally, in small quantities, in meat and dairy products from ruminants. Most trans fats consumed today, however, are industrially created as a side effect of partial hydrogenation of plant oils — a process developed in the early 1900s and first commercialized as Crisco in 1911. Partial hydrogenation changes a fat's molecular structure (raising its melting point and reducing rancidity) but this process also results in a proportion of the changed fat becoming trans fat.
Unlike other fats, trans fats are neither required nor beneficial for health.<ref name=p423>Nat' Academies Press, Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients) (2005) page 423</ref> Eating trans fat increases the risk of coronary heart disease.<ref name=p504>Nat' Academies Press, Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients) (2005) page 504</ref> For these reasons, health authorities worldwide recommend that consumption of trans fat be reduced to trace amounts. Trans fats from partially hydrogenated oils are generally considered to be more of a health risk than those occurring naturally.<ref name=nejmreview>Mozaffarian D, Katan MB, Ascherio A, Stampfer MJ, Willett WC (April 2006). "Trans Fatty Acids and Cardiovascular Disease". New England Journal of Medicine 354 (15): 1601-1613. PMID 16611951</ref>
Trans fats are increasingly being linked to chronic health conditions (see below), are tightly regulated in a few countries, are mandatory on product labels in many others, and are the central issue in several ongoing lawsuits (particularly against fast food outlets). Many companies are voluntarily removing trans fats from their products, or establishing trans-free product lines.
Chemically, trans fats are made of the same building blocks as non-trans fats, but have a different shape. In trans fat molecules, the double bonds between carbon atoms (characteristic of all unsaturated fats) are in the trans rather than the cis configuration, resulting in a more straight rather than a kinked shape. As a result, trans fats are less fluid and have a higher melting point than the equivalent cis fats.
Contents |
[edit] Presence in food
Trans fats occur naturally in the milk and body fat of ruminants (such as cows and sheep) at a level of 2-5% of total fat.<ref name=Canada>Health Canada / Santé Canada TRANSforming the Food Supply</ref> They originate in the rumens of these animals. Animal-based fats were once the only trans fats consumed, but by far the largest amount of trans fat consumed today is created by the processed food industry as a side-effect of partially hydrogenating unsaturated plant fats (generally vegetable oils). These hydrogenated fats have displaced natural solid fats and liquid oils in many areas, notably in the fast food, snack food, fried food and baked good industries. Vegetable shortenings are partially hydrogenated fats packaged for home use, and some margarines contain a large proportion of trans fat. Foods containing artificial trans fats formed by partially hydrogenating plant fats may contain up to 45% trans fat compared to their total fat.<ref name=Canada/>
Benefits of hydrogenating plant-based fats for food manufacturers include an increased product shelf life and decreased refrigeration requirement. Partial hydrogenation raises the melting point of fat, producing a semi-solid material, which is much more desirable than liquid oils for use in baking. Plant-based hydrogenated vegetable oils are much less expensive than the animal fats traditionally favored by bakers, such as butter or lard, and may be more readily available or less expensive than semi-solid plant fats such as palm oil.
Because partial hydrogenation of plant oils can replace animal fats, the resulting products can be consumed (barring other ingredient and preparation violations) by adherents to Kashrut (kosher) and Halal, as well as by adherents to vegetarianism in Buddhism, ahimsa in Jainism and Hinduism, veganism, and other forms of vegetarianism.
It has been established that trans fats in human milk fluctuate with maternal consumption of trans fat, and that the amount of trans fats in the bloodstream of breastfed infants fluctuates with the amounts found in their milk. Reported percentages of trans (compared to total fats) in human milk range from 1% in Spain, 2% in France and 4% in Germany to 7% in Canada.<ref>Innis, Sheila M and King, D Janette (1999). "trans Fatty acids in human milk are inversely associated with concentrations of essential all-cis n-6 and n-3 fatty acids and determine trans, but not n-6 and n-3, fatty acids in plasma lipids of breast-fed infants". American Journal of Clinical Nutrition 70 (3): 383–390.</ref>
An analysis of samples collected in 2004 and 2005 found that trans fats vary widely within the same product at chain restaurants. At McDonald's, for example, fries served in New York City contained twice as much trans fat as in Hungary, and 28 times as much trans as in Denmark (where trans fats are effectively banned). At KFC, the pattern was reversed with Hungary's product containing twice the fat of the New York product. Even within the US there was variation, with fries in New York containing 30% more trans fat than those from Atlanta.<ref>What's in that french fry? Fat varies by city, AP story concerning PMID 16611965]</ref>
[edit] Nutritional guidelines
The National Academy of Sciences (NAS) advises the United States and Canadian governments on nutritional science for use in public policy and product labelling programs. Their 2002 Dietary reference intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids <ref>Nat' Academies Press, Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients) (2005) page i</ref> contains their findings and recommendations regarding consumption of Trans fat (summary).
Their recommendations are based on two key facts. First, "trans fatty acids are not essential and provide no known benefit to human health",<ref name=p423/> whether of animal or plant origin.<ref>Nat' Academies Press, Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients) (2005) page 447</ref> Second, while both saturated and trans fats increase levels of LDL cholesterol (so-called bad cholesterol), trans fats also lower levels of HDL cholesterol (so-called good cholesterol) <ref name=p504/>; this increases the risk of coronary heart disease (CHD). The NAS is concerned "that dietary trans fatty acids are more deleterious with respect to CHD than saturated fatty acids".<ref name=p504/> This analysis is supported by a 2006 New England Journal of Medicine (NEJM) scientific review that states "from a nutritional standpoint, the consumption of trans fatty acids results in considerable potential harm but no apparent benefit."<ref name=nejmreview/>
Because of these facts and concerns, the NAS has concluded there is no safe level of trans fat consumption. There is no adequate level, recommended daily amount or tolerable upper limit for trans fats. This is because any incremental increase in trans fat intake increases the risk of coronary heart disease.<ref name=p504/>
Despite this concern, the NAS dietary recommendations have not recommended the elimination of trans fat from the diet. This is because trans fat is naturally present in many animal foods, and therefore in most non-vegan diets; its removal from ordinary diets might introduce undesirable side effects and nutritional imbalances if proper nutritional planning is not undertaken. The NAS has therefore "recommended that trans fatty acid consumption be as low as possible while consuming a nutritionally adequate diet".<ref>Nat' Academies Press, Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients) (2005) page 424</ref> Like the NAS, the World Health Organization has tried to balance public health goals with a practical level of trans fat consumption, recommending in 2003 that trans fats be limited to less than 1% of overall energy intake.<ref name=Canada/>
The US National Dairy Council has asserted that the trans fats present in animal foods are of a different type than those in partially hydrogenated oils, and do not appear to exhibit the same negative effects.<ref name=dairy>National Dairy Council letter</ref> While a recent scientific review agrees with the conclusion (stating that "the sum of the current evidence suggests that the public health implications of consuming trans fats from ruminant products are relatively limited") it cautions that this may be due to the relatively low consumption of trans fats from animal sources compared to artificial ones.<ref name=nejmreview/>
[edit] History
Nobel laureate Paul Sabatier worked in the 1890s to develop the chemistry of hydrogenation which enabled the margarine, oil hydrogenation, and synthetic methanol industries.<ref>Paul Sabatier Biography at the Nobel prize site. (Reprinted from Nobel Lectures, Chemistry 1901-1921, Elsevier Publishing Company, Amsterdam, 1966.)</ref> While Sabatier only considered hydrogenation of vapours, the German chemist Wilhelm Normann showed in 1901 that liquid oils could be hydrogenated and patented the process in 1902.<ref>HBW Patterson (2001) "Hydrogenation" SCI Lectures Paper Series</ref> In 1909, Procter & Gamble acquired the US rights to the Normann patent<ref>History of Soybeans and Soyfoods: 1100 B.C. to the 1980s. Unpublished manuscript by William Shurtleff and Akiko Aoyagi</ref>; in 1911, they began marketing the first hydrogenated shortening, Crisco (composed largely of partially hydrogenated cottonseed oil). Further success came from the marketing technique of giving away free cookbooks with every recipe calling for Crisco. Hydrogenation strongly stimulated whaling, as it made it possible to stabilize whale oil for human consumption.
Production of hydrogenated fats increased steadily until the 1960s as artificially hardened liquid oils replaced naturally hard saturated animal fats in the US and other western countries. At first, the argument was a financial one due to lower costs; however, advocates also said that the unsaturated trans fats of margarine were healthier than the saturated fats of butter.<ref name=harvard>Ascherio A, Stampfer MJ, Willett WC. Trans fatty acids and coronary heart disease. Retrieved on 2006-09-14.</ref> The Center for Science in the Public Interest (CSPI) campaigned against the use of saturated fats for fast food cooking starting in 1984. When fast food companies replaced the saturated fat with partially hydrogenated unsaturated fats, CSPI's campaign against them ended. While CSPI defended trans fats in their 1987 Nutrition Action newsletter, by 1992 CSPI began to speak against trans fats and is currently strongly against their use.<ref>Mary G. Enig, PhD. The Tragic Legacy of Center for Science in the Public Interest (CSPI). Retrieved on 2006-05-02.</ref>
There were suggestions in the scientific literature as early as 1988 that trans fats could be a cause of the large increase in coronary artery disease.<ref name=harvard/><ref>Booyens J, Louwrens CC, Katzeff IE (1988). "The role of unnatural dietary trans and cis unsaturated fatty acids in the epidemiology of coronary artery disease". Medical Hypotheses 25 (3): 175-182. PMID 3367809</ref> In 1994, it was estimated that trans fats caused 30,000 deaths annually in the US from heart disease.<ref>Willett WC, Ascherio A (1995). "Trans fatty acids: are the effects only marginal?". American Journal of Public Health 85 (3): 411-412. PMID 8179036</ref>
[edit] Chemistry
From a chemical perspective, fats are large E-shaped molecules that support three fatty acids on a backbone. What is commonly termed a trans fat is more accurately described as a trans fatty acid. Fatty acid molecules consist of a backbone of carbon atoms surrounded by hydrogen atoms (as well as a carboxyl group — located at the end of the molecule — that we will not be concerned with in this discussion). Fatty acids are characterized as saturated or unsaturated based on the number of hydrogen atoms in the acid. If the molecule contains the maximum possible number of hydrogen atoms then it is saturated; otherwise, it is unsaturated.
Carbon atoms are tetravalent, forming four covalent bonds with other atoms, while hydrogen atoms bond with only one other atom. In saturated fatty acids, each carbon atom is connected to its two neighbour carbon atoms as well as two hydrogen atoms (see structure diagram, below). In unsaturated fatty acids the carbon atoms that are missing hydrogen atoms are joined by double bonds rather than single bonds (see structure graphic below) so that each carbon atom participates in four bonds.
Hydrogenation of an unsaturated fatty acid refers to the addition of hydrogen atoms to the acid, causing double bonds to become single ones as carbon atoms acquire new hydrogen partners (to maintain four bonds per carbon atom). Full hydrogenation results in a molecule containing the maximum amount of hydrogen (in other words the conversion of an unsaturated fatty acid into a saturated one). Partial hydrogenation results in the addition of hydrogen atoms at some of the empty positions, with a corresponding reduction in the number of double bonds. Commercial hydrogenation is typically partial in order to obtain a malleable fat that is solid at room temperature, but melts upon baking (or consumption).
In most naturally occuring unsaturated fatty acids, the hydrogen atoms are on the same side of the double bonds of the carbon chain (cis configuration). However, partial hydrogenation reconfigures most of the double bonds that do not become chemically saturated, twisting them so that the hydrogen atoms end up on different sides of the chain. This type of configuration is called trans, which means "across" in Latin.
| Molecular structure of different fatty acids | ||
|---|---|---|
| Saturated fat | Cis-unsaturated fatty acid | Trans-unsaturated fatty acid |
| saturated carbon atoms (each with 2 hydrogens) joined by a single bond | unsaturated carbon atoms (each with 1 hydrogen) joined by a double bond. Cis configuration. | unsaturated carbon atoms (each with 1 hydrogen) joined by a double bond. Trans configuration. |
The same molecule, containing the same number of atoms, with the double bond in the same location, can be either a trans or a cis fatty acid depending on the conformation of the double bond. For example, oleic acid and elaidic acid are both unsaturated fatty acids with the chemical formula C18H34O2. They both have a double bond 9 carbon atoms from the end of the molecule. It is the conformation of this bond that sets them apart. The conformation has an implication for the orientation of the rest of the molecule. The trans configuration is straighter, while the cis configuration is noticeably kinked as can be seen from the following three-dimensional representation.
| Oleic acid | Elaidic acid |
|---|---|
| Oleic acid is a cis unsaturated fatty acid that comprises 55-80% of olive oil. | Elaidic acid is a trans unsaturated fatty acid often found in hydrogenated vegetable oils. |
| These fatty acids are geometric isomers (chemically identical except for the arrangement of the double bond). | |
The trans fatty acid elaidic acid has different chemical properties owing to the slightly different bond configuration. Notably, it has a much higher melting point, 46.5 °C rather than oleic acid's 13.5 °C.
In food production, the goal is not to simply change the configuration of double bonds while maintaining the same ratios of hydrogen to carbon. Instead, the goal is to decrease the number of double bonds and increase the amount of hydrogen in the fatty acid. This changes the consistency of the fatty acid and makes it less prone to rancidity (in which free radicals attack double bonds). Production of trans fatty acids is therefore a side-effect of partial hydrogenation.
Researchers at the United States Department of Agriculture have investigated whether hydrogenation can be achieved without the side effect of trans fat production. They varied the pressure under which the chemical reaction was conducted — applying 1400 kPa (200 psi) of pressure to soybean oil in a 2 litre vessel while heating it to between 140 °C and 170 °C. The standard 140 kPa (20 psi) process of hydrogenation produces a product of about 40% trans fatty acid by weight, compared to about 17% using the high pressure method. Blended with unhydrogenated liquid soybean oil, the high pressure processed oil produced margarine containing 5 to 6% trans fat. Based on current U.S. labelling requirements (see below) the manufacturer could claim the product was free of trans fat.<ref>FJ Eller (2005). "Preparation of spread oils meeting U.S. Food and Drug Administration Labeling requirements for trans fatty acids via pressure-controlled hydrogenation". Journal of Agricultural and Food Chemistry 53 (15): 5982–5984. PMID 16028984.</ref>
[edit] Health risks
Partially hydrogenated vegetable oils have been an increasingly significant part of the human diet for about 100 years (particularly so in the latter half of the 20th century), and some deleterious effects of trans fat consumption are scientifically accepted, forming the basis of the health guidelines discussed above.
The exact biochemical methods by which trans fats produce specific health problems are a topic of continuing research. For example, the mechanisms through which trans fats contribute to coronary heart disease are fairly well understood, while the mechanism for trans fat's effect on diabetes is under investigation.
[edit] Coronary heart disease
The primary health risk identified for trans fat consumption is an elevated risk of coronary heart disease (CHD).<ref name=TRANSformingApx9>TRANSforming the food supply, Appendix 9iiiConsultation on the health implications of alternatives to trans fatty acids: Summary of Responses from Experts</ref> A comprehensive review of studies of trans fats was published in 2006 in the New England Journal of Medicine that concludes that there is a strong and reliable connection between trans fat consumption and CHD.<ref name=nejmreview/>
The major evidence for the effect of trans fat on CHD comes from the Nurses' Health Study (NHS) — a cohort study that has been following 120,000 female nurses since its inception in 1976.
Hu and colleagues analyzed data from 900 coronary events from the NHS population during 14 years of followup. He determined that a nurse's CHD risk roughly doubled (relative risk of 1.94) for each 2% increase in trans fat calories consumed (instead of carbohydrate calories). By contrast, it takes more than a 15% increase in saturated fat calories (instead of carbohydrate calories) to produce a similar increase in risk. Eating non-trans unsaturated fats instead of carbohydrates reduces the risk of CHD rather than increasing it.<ref name=nhs97>Hu, FB, Stampfer, MJ, Manson, JE, Rimm, E, Colditz, GA, Rosner, BA, Hennekens, CH, Willett, WC (1997). "Dietary fat intake and the risk of coronary heart disease in women". New England Journal of Medicine 337 (21): 1491-1499. PMID 9366580. Online Copy (free with registration).</ref>
Hu also reports on the benefits of reducing trans fat consumption. Replacing 2% of food energy from trans fat with non-trans unsaturated fats more than halves the risk of CHD (53%). By comparison, replacing a larger 5% of food energy from saturated fat with non-trans unsatured fats reduces the risk of CHD by 43%.<ref name=nhs97/>
There are two accepted measures of risk for coronary heart disease, both blood tests. The first considers ratios of two types of cholesterol, the other the amount of a cell-signalling cytokine called C-reactive protein. The ratio test is more accepted, while the cytokine test may be more powerful but is still being studied.<ref name=TRANSformingApx9/> The effect of trans fat consumption has been documented on each as follows:
- Cholesterol ratio: This ratio compares the levels of LDL (so-called "bad" cholesterol) to HDL (so-called "good" cholesterol). Trans fat behaves like saturated fat by raising the level of LDL, but unlike saturated fat it has the additional effect of decreasing levels of HDL. The net increase in LDL/HDL ratio with trans fat is approximately double that due to saturated fat.<ref>A Ascherio (1999). "Trans fatty acids and coronary heart disease.". New England Journal of Medicine 340 (25): 1994–1998.</ref> (Higher ratios are worse.)
- C-reactive protein (CRP): A study of over 700 nurses showed that those in the highest quartile of trans fat consumption had blood levels of CRP that were 73% higher than those in the lowest quartile.<ref>Esther Lopez-Garcia (2005). "Consumption of Trans Fatty Acids Is Related to Plasma Biomarkers of Inflammation and Endothelial Dysfunction". The Journal of Nutrition 135 (3): 562–566. PMID 15735094.</ref>
Another study considered deaths due to CHD, with consumption of trans fats being linked to an increase in mortality, and consumption of polyunsaturated fats being linked to a decrease in mortality.<ref name=TRANSformingApx9/><ref>Oh, K, Hu, FB, Manson, JE, Stampfer, MJ, Willett, WC (2005). "Dietary fat intake and risk of coronary heart disease in women: 20 years of follow-up of the nurses' health study". American Journal of Epidemiology 161 (7): 672-679. PMID 15781956</ref>
[edit] Other effects
There has been suggestion that the negative consequences of trans fat consumption go beyond the cardiovascular risk. In general, there is much less scientific consensus that eating trans fat specifically increases the risk of other chronic health problems:
- Cancer: There is no scientific consensus that consumption of trans fats significantly increases cancer risks across the board.<ref name=TRANSformingApx9/> The American Cancer Society states that a relationship between trans fats and cancer "has not been determined."<ref>Common questions about diet and cancer</ref> However, one recent study has found connections between trans fat and prostate cancer.<ref>Chavarro et al., "A prospective study of blood trans fatty acid levels and risk of prostate cancer," Proc. Amer. Assoc. Cancer Res., Volume 47, 2006 [1]</ref>
- Diabetes: There is a growing concern that the risk of type 2 diabetes increases with trans fat consumption.<ref name=TRANSformingApx9/> However, consensus has not been reached.<ref name=nejmreview/> For example, one study found that risk is higher for those in the highest quartile of trans fat consumption.<ref>Hu, FB, van Dam, RM, Liu, S (2001). "Diet and risk of Type II diabetes: the role of types of fat and carbohydrate". Diabetologia 44 (7): 805-817. PMID 11508264</ref> Another study has found no diabetes risk once other factors such as total fat intake and BMI were accounted for.<ref>van Dam RM, Stampfer M, Willett WC, Hu FB, Rimm EB (2002). "Dietary fat and meat intake in relation to risk of type 2 diabetes in men". Diabetes care 25 (3): 417-424. PMID 11874924</ref>
- Obesity: Research indicates that trans fat may increase weight gain and abdominal fat, despite a similar caloric intake.<ref>Gosline, Anna Why fast foods are bad, even in moderation New Scientist 12 June 2006</ref> A 6-year experiment revealed that monkeys fed a trans-fat diet gained 7.2% of their body weight, as compared to 1.8% for monkeys on a mono-unsaturated fat diet. Although obesity is frequently linked to trans fat in the popular media,<ref>e.g. Trans Fat Press Conference by Tommy G. Thompson, US Secretary of health and human services</ref> this is generally in the context of eating too many calories; there is no scientific consensus connecting trans fat and obesity.
- Liver Dysfunction: Trans fats are metabolized differently by the liver than other fats and interfere with delta 6 desaturase. Delta 6 desaturase is an enzyme involved in converting essential fatty acids to arachidonic acid and prostaglandins, both of which are important to the functioning of cells.<ref>M Mahfouz (1981). "Effect of dietary trans fatty acids on the delta 5, delta 6 and delta 9 desaturases of rat liver microsomes in vivo". Acta biologica et medica germanica 40 (12): 1699–1705.</ref>
[edit] Public response and regulation
The lengthy political process of balancing the public health versus private profit from the public sale of processed foods containing artificially hydrogenated oils and fats continues today. Some countries are considering a complete ban against artificial hydrogenation products in food.
[edit] Canada
Canada is one of the largest consumers of trans fats in the world.<ref>Health Canada Trans Fat</ref> In November 2004, an opposition day motion seeking a ban similar to Denmark's was introduced by Jack Layton of the New Democratic Party, and passed through the House of Commons by an overwhelming 193-73 vote.<ref>Dosanjh snubs House, MP says. Retrieved on 2006-05-02.</ref>
Since December 2005, Health Canada has required that food labels list the amount of trans fat in the nutrition facts section for most foods. Generally, products with less than 0.2 grams of trans fat per serving are considered to be free of trans fats and may be labelled as such (although this leads to questions of serving sizes). In Canada, trans fat quantities on labels include naturally occurring trans fats from animal sources.<ref>Information letter: Labelling of trans fatty acids</ref>
In June 2006, a task force co-chaired by Health Canada and the Heart and Stroke Foundation of Canada recommended a limit of 5% trans fat (to total fat) ratio in all products sold to consumers in Canada (2% for tub margarines and spreads).<ref name=Canada/> The amount was selected such that "most of the industrially produced trans fats would be removed from the Canadian diet, and about half of the remaining trans fat intake would be of naturally occurring trans fats". This recommendation has been endorsed by the Canadian Restaurant and Foodservices Association<ref>Restaurant industry commits to Trans Fat Task Force recommendations</ref> and the Food and Consumer Products of Canada has congratulated the task force on the report.<ref>Food industry congratulates Trans Fat Task Force on report</ref>
[edit] Denmark
Denmark became the first country to introduce laws strictly regulating the sale of many foods containing trans fats in March 2003, a move which effectively bans partially hydrogenated oils. Naturally present trace amounts of trans fats in dairy and meat products are unaffected by these bills. The UK campaigning body tfX offers an English translation on its Denmark's trans fat law page.
[edit] European Union
The European Food Safety Authority was asked to produce a scientific opinion on trans fats.<ref>European Food Safety Authority Opinion of the Scientific Panel on Dietetic Products, Nutrition and Allergies on a request from the Commission related to the presence of trans fatty acids in foods and the effect on human health of the consumption of trans fatty acids The EFSA Journal (2004) 81, 1-49</ref>
[edit] United Kingdom
In October 2005, the Food Standards Agency (FSA) asked for better labelling in the UK.<ref>Gray, Richard. "Forced to own up to the killer fat in our food", Scotsman.com, February 5, 2006.</ref> In the 29 July 2006 edition of the British Medical Journal, an editorial also called for better labelling.<ref>BBC 27 July 2006 Call to label hidden fats in food</ref><ref>Clarke, Robert; Lewington, Sarah Trans fatty acids and coronary heart disease British Medical Journal 2006;333:214 (29 July), doi:10.1136/bmj.333.7561.214</ref>
[edit] United States
Before 2006, consumers in the United States could not directly determine the presence (or quantity) of trans fats in food products. This information could be inferred from the ingredient list, notably from the hydrogenated ingredients.
On July 11, 2003, the Food and Drug Administration (FDA) issued a regulation<ref>(21 CFR 101.9 (c)(2)(ii)): Trans Fatty Acids in Nutrition Labeling</ref> requiring manufacturers to list trans fat on the Nutrition Facts panel of foods and some dietary supplements.<ref>FDA Acts to Provide Better Information to Consumers on Trans Fats. Food and Drug Administration. Retrieved on 2005-07-26.</ref> The new labeling rule allowed for immediate voluntary compliance with mandatory compliance by January 1, 2006 (although companies may petition for an extension to January 1, 2008). The regulation allows trans fat levels of less than 0.5 grams per serving to be labeled as 0 grams per serving, or trans fat free. (In this case, manufacturers may use the synonyms "free", "without," "no" and "zero" in their packaging claims.) This can be compared to Canada in which the threshold is 0.2 grams. (It should be noted that trans fats consumed may be significant, if many small servings are eaten together.) The FDA defines trans fats as containing one or more trans linkages that are not in a conjugated system. This is an important distinction, as it distinguishes non-conjugated synthetic trans fats from naturally occurring fatty acids with conjugated trans double bonds, such as conjugated linoleic acid.
The FDA estimates that by 2009, trans fat labeling will have prevented from 600 to 1,200 cases of coronary heart disease and 250 to 500 deaths each year. This benefit is expected to result from consumers choosing alternative foods lower in trans fats as well as manufacturers reducing the amount of trans fats in their products.
Some US cities are acting to reduce consumption of trans fats. In May 2005, Tiburon, California, became the first American city where all restaurants voluntarily cook with trans fat-free oils.<ref>Project Tiburon of Ban Trans Fats</ref>
New York City has embarked on a campaign to reduce consumption of trans fats, noting that heart disease is the primary cause of resident deaths. This has included a public education campaign (see trans fat pamphlet) and a request to restaurant owners to voluntarily eliminate trans fat from their offerings.<ref>City of New York press release: Health department asks restaurateurs and food suppliers to voluntarily make an oil change and eliminate artificial trans fat</ref> Finding that the voluntary program was not successful, New York City's Board of Health has solicited public comments on a proposal to ban artificial trans fats in restaurants.<ref>Health department proposes two changes to city's health code for public comment</ref> A final vote by the board is planned for December. If approved, this would make New York the first large US city to strictly limit trans fats in restaurants.
Chicago is considering a ban on oils containing trans fats for large chain restaurants.<ref>Burke Serves Up Another Trans Fat Plan Southwest News Herald article</ref>
[edit] Food industry response
Some major food chains have chosen to remove or reduce trans fats in their products. In some cases these changes have been voluntary. In other cases, however, food vendors have been targeted by legal action that has generated a lot of media attention. In May 2003, BanTransFats.com Inc., a U.S. non-profit corporation, filed a lawsuit against the food manufacturer Kraft Foods in an attempt to force Kraft to remove trans fats from the Oreo cookie. The lawsuit was withdrawn when Kraft agreed to work on ways to find a substitute for the trans fat in the Oreo.
Similarly, in 2006, the Center for Science in the Public Interest sued KFC over its use of trans fats in fried foods.<ref>KFC Sued for Fouling Chicken with Partially Hydrogenated Oil: Lawsuit Aimed at Eliminating, or Disclosing Use of Artery-Clogging Frying Oil</ref><ref>Class Action Complaint</ref> KFC reviewed alternative oil options, saying "there are a number of factors to consider including maintaining KFC's unique taste and flavor of Colonel Sanders' Original Recipe."<ref>The New York Times (Marian Burros) KFC Is Sued Over the Use of Trans Fats in Its Cooking 14 June 2006</ref> On October 30, 2006, KFC announced that it will replace the partially hydrogenated soybean oil it currently uses with a trans-fat free low linolenic soybean oil in all restaurants in the US by April 2007, although its biscuits will still contain trans-fats.<ref>KFC announces switch to zero trans fat cooking oil following two-year test for same great taste (press release)</ref><ref>BBC (Guto Harri) KFC cuts out unhealthy trans-fats 30 October 2006</ref> Despite the US-specific nature of the lawsuit, KFC is making changes outside of the US as well; in Canada, KFC's brand owner is switching to trans-fat free Canadian canola oil by early 2007.<ref>KFC Canada phasing in zero grams trans fat menu in all 786 restaurants nationally early in the new year (press release)</ref>
Some well-publicized changeovers have not come to fruition. In 2002, McDonald's promised to reduce the trans fat in its frying oils, but delayed its plans several months later. In 2006, McDonald's announced it was making "very good progress" but had yet to replace its oils over worries the change would "jeopardize the iconic nature of [their] french fry". It stated, however, that it would be ready should New York City implement its proposed ban.<ref>"McDonald's CEO: Progress, No New Oil Yet (AP story)". Retrieved on November 15, 2006.</ref>
The J.M. Smucker Company, American manufacturer of Crisco (the original partially hydrogenated vegetable shortening), have released a new formulation made from solid fully hydrogenated palm oil cut with soybean oil and sunflower oil. This blend yields an equivalent shortening much like the previous partially hydrogenated Crisco, and is labelled zero grams of trans fat per 1 tablespoon serving (as compared with 1.5 grams per tablespoon of original Crisco).<ref>Crisco nutritional facts</ref> Crisco does not have a trans-free offering in other locations — in Canada, for example, the lowest trans fat Crisco is Crisco Golden that contains 0.4 grams of trans fat per serving.
The Walt Disney Company will begin getting rid of trans fats in meals at US theme parks (Disneyland, Walt Disney World, etc.) by the end of 2007, and will stop the inclusion of trans fats in licensed or promotional products by 2008.<ref>Disney to serve healthier foods at parks Yahoo! news article on plans to eliminate trans fats in Disney's theme parks</ref>
[edit] References
<references/>
[edit] See also
[edit] External links
da:Transfedtsyre de:Transfettsäuren es:Ácido graso trans it:Acidi grassi trans hu:Transz-zsírsav nl:Transvet pt:Gordura trans fi:Transrasva sv:Transfett ja:トランス脂肪酸 zh:反式脂肪
