摘要：We examined the impact of regulatory action to reduce levels of artificial trans–fatty acids (TFAs) in food. We searched Medline, Embase, ISI Web of Knowledge, and EconLit (January 1980 to December 2012) for studies related to government regulation of food- or diet-related health behaviors from which we extracted the subsample of legislative initiatives to reduce artificial TFAs in food. We screened 38 162 articles and identified 14 studies that examined artificial TFA controls limiting permitted levels or mandating labeling. These measures achieved good compliance, with evidence of appropriate reformulation. Regulations grounded on maximum limits and mandated labeling can lead to reductions in actual and reported TFAs in food and appear to encourage food producers to reformulate their products. A high intake of dietary trans–fatty acids (TFAs) has been associated with an increased risk of cardiovascular disease. 1–4 Artificial TFAs, also known as industrially produced trans fats or hydrogenated fats, are sometimes used in pre-prepared food as a cost-effective way to increase shelf life and improve the texture and taste of baked goods. 4,5 Although TFAs cannot be completely eliminated from the food supply—they occur naturally at low levels in many food items such as meat and dairy products—levels of artificial or industrially hardened TFAs can be reduced. Guidelines worldwide recommend limiting consumption to less than 1% to 2% of total dietary energy. 1–3 On average, consumption in countries such as the United States and the United Kingdom is close to this level, although there can be wide variation within the population. 1,6 The National Institute for Health and Clinical Excellence in the United Kingdom estimated that reducing TFAs to 0.7% of total fat energy consumed could save about 571 000 life-years. 7 Governments face pressure to intervene to control levels of TFAs in the food supply to protect human health. 4,8 Most recently, the US Food and Drug Administration announced that partially hydrogenated oils, an important source of artificial TFAs, would be downgraded from “generally recognized as safe” for use in food by 2015, effectively banning them. 9 Options for intervention include mandated maxima for TFAs in food (i.e., bans), consumer labeling to guide choices, education to encourage consumers to change dietary habits, and voluntary agreements with food producers to limit the use of artificial TFAs. 10,11 Such voluntary agreements have helped reduce levels of artificial TFAs in countries such as the United Kingdom and the Netherlands, 12,13 although the impact of such agreements depends on the extent to which industry is willing to agree to and abide by the arrangement. 14 Labeling mandates aim to guide consumer choice and put pressure on manufacturers to reduce artificial TFAs in response to consumer demand. Informed individuals can choose to avoid artificial TFAs by not eating the types of food that contain them, so appropriate labeling, along with information and education, may also have an important role. A World Health Organization report that included industry self-regulation found that all types of policy intervention reduced artificial TFAs in food; bans were reported to be the most effective, although the success of labeling and voluntary initiatives varied by type of food. 15 Our review independently updates this evidence, with a focus on enforced or enforceable regulatory interventions. Enforced standards such as maximum limits can create a level playing field for food manufacturers, providing a clear, robust framework for action. Furthermore, they can lead to reduced consumption that does not depend on changes in food choices, providing benefits across all socioeconomic groups. Mandatory approaches face a range of barriers, because they can be politically unpopular, require a long-term commitment to monitoring and enforcement, and have unintended consequences. Legislation to control levels in a country may spill over to affect other countries, either beneficially through exporting foods that contain lower levels of artificial TFAs or detrimentally if manufacturers export artificial TFAs abroad in search of new and permissive markets. 16 We examined how different types of regulations have affected levels of artificial TFAs in food worldwide. Our primary outcome was the availability of artificial TFAs in food. Secondary outcomes included any other measured outcomes the studies reported; these could be changes to individuals’ food purchasing or consumption behaviors or manufacturers’ responses such as reformulation, substitution of ingredients, promotional activities, or price changes.
