The amount of trans fat in a person's diet is linked with his or her risk of developing or dying from heart disease, a new review of studies suggests. 
 
 The review showed that people who ate higher amounts of trans fat were 34 percent more likely to die from any cause over the periods studied, compared with people who ate lower amounts of trans fat. The studies of death rates that the researchers analyzed tracked people over seven to 10 years. 
 
 People who ate more trans fat were also 28 percent more likely to die from heart disease, and 21 percent more likely to develop heart disease, compared with people who ate smaller amounts of trans fats. 
 
 However, the source of trans fats in the diet may be important, said Russell de Souza, a co-author of the study and an assistant professor of epidemiology and biostatistics at McMaster University in Hamilton, Ontario. [3 Tips for Eating Less Trans Fat] 
 
 "Industrially produced" trans fats, which are man-made fats added to foods such as shortening and baked goods, appear to be more harmful than "ruminant" trans fats, which naturally occur in smaller amounts in foods such as butter and beef, de Souza told Live Science. 
 
 The review's findings support efforts by the U.S. Food and Drug Administration to remove "industrially produced" trans fats from the nation's food supply, de Souza said. 
 
 The researchers did not find evidence that healthy adults who consume diets higher in saturated fats — the kind of fat found in meat, milk, cheese and egg yolks — face a greater chance of heart disease, according to the findings, published today (Aug. 11) in the journal The BMJ. 
 
 However, the analysis couldn't confidently rule out that saturated fat may increase a person's risk of dying from heart disease," said de Souza, who is also a registered dietitian. 
 
 Better-designed studies are needed to help researchers fully understand the role of saturated fats in disease, he said. 
 
 For the review, researchers gathered data collected during 73 studies on saturated fats and 50 studies on trans fats published over the past 30 years. The analysis relied on data from observational studies, which follow groups of people over time to see what diseases they develop, de Souza explained. 
 
 Healthful eating 
 
 Currentdietary guidelines in the United States call for healthy adults to limit the saturated fats in their diets to no more than 10 percent of their daily calories.But for people at increased risk of heart disease, the American Heart Association recommends consuming no more than 6 percent of total daily calories from saturated fats. 
 
 The U.S. Dietary Guidelines also recommend limiting trans fats — such as the partially hydrogenated oils often found in cookies, crackers, baked goods and stick margarines — to less than 1 percent of daily calories, to reduce the risk of heart disease and stroke. 
 
 Some researchers have called for increasing the amount of saturated fat allowed in the diet of healthy adults because some emerging evidence suggests there is little difference in heart disease risk based on levels of saturated fats. However, de Souza said the new review study does not support recommendations to increase saturated-fat intakes. 
 
 He said that, in many of the published studies that compare the risks of people who follow diets higher in saturated fats to those who eat lower amounts of saturated fats, the people who ate lower amounts of saturated fat were also eating more refined carbohydrates. But replacing saturated fats with refined carbohydrates, such as sugars and starches, is not the best way to reduce health risks, de Souza said. 
 
 It's better to replace foods such as beef, lamb, pork and high-fat dairy products with fruits and vegetables, whole grains, beans, peas and nuts, as well as unsaturated fats, such as olive and canola oils, he said. 
 
 "It's important for people to remember there is no one nutrient or food that's responsible for all heart disease, diabetes or death," de Souza said. "The whole diet matters." 
 
 Follow Live Science @livescience, Facebook & Google+. Originally published on Live Science. ||||| Saturated fats are not associated with an increased risk of death, heart disease, stroke, or type 2 diabetes, finds a study published in The BMJ this week. However, the findings show that trans fats are associated with greater risk of death and coronary heart disease. 
 
 The study confirms previous suggestions that industrially produced trans fats might increase the risk of coronary heart disease and calls for a careful review of dietary guidelines for these nutrients. 
 
 Guidelines currently recommend that saturated fats are limited to less than 10%, and trans fats to less than 1% of energy to reduce risk of heart disease and stroke. 
 
 Saturated fats come mainly from animal products, such as butter, cows' milk, meat, salmon and egg yolks, and some plant products such as chocolate and palm oils. Trans unsaturated fats (trans fats) are mainly produced industrially from plant oils (a process known as hydrogenation) for use in margarine, snack foods and packaged baked goods. 
 
 Contrary to prevailing dietary advice, a recent evidence review found no excess cardiovascular risk associated with intake of saturated fat. In contrast, research suggests that industrial trans fats may increase the risk of coronary heart disease. 
 
 To help clarify these controversies, researchers in Canada analysed the results of observational studies assessing the association between saturated and/or trans fats and health outcomes in adults. 
 
 Study design and quality were taken into account to minimise bias, and the certainty of associations were assessed using a recognised scoring method. 
 
 The team found no clear association between higher intake of saturated fats and all cause mortality, coronary heart disease (CHD), cardiovascular disease (CVD), ischemic stroke or type 2 diabetes, but could not, with confidence, rule out increased risk for CHD death. They did not find evidence that diets higher in saturated fat reduce cardiovascular risk. 
 
 However, consumption of industrial trans fats was associated with a 34% increase in all cause mortality, a 28% increased risk of CHD mortality, and a 21% increase in the risk of CHD. 
 
 Inconsistencies in the included studies meant that the researchers could not confirm an association between trans fats and type 2 diabetes. And they found no clear association between trans fats and ischemic stroke. 
 
 The researchers point out that the certainty of associations between saturated fat and all outcomes was "very low," which means that further research is very likely to have an important impact on our understanding of the association of saturated fats with disease. The certainty of associations of trans fat with CHD outcomes was "moderate" and "very low" to "low" for other associations. 
 
 They also stress that their results are based on observational studies, so no definitive conclusions can be drawn about cause and effect. However, they say their analysis "confirms the findings of five previous systematic reviews of saturated and trans fats and CHD." 
 
 And they conclude that dietary guidelines for saturated and trans fatty acids "must carefully consider the effect of replacement nutrients." 
 
 ### ||||| Donut eat them (Image: Roy Ooms/Getty) 
 
 Here’s something to chew over. Eating more trans fats is linked to coronary heart disease, while eating saturated fats is not. That’s according to an analysis of 123 studies of dietary fat and cardiovascular health. 
 
 Most dietary advice recommends limiting the consumption of saturated fats, which are found in butter, milk, meat and egg, due to the risk of developing heart disease. But Russell de Souza of McMaster University in Ontario, Canada, and his team were unable to find a clear association between these fats and the chances of heart or cardiovascular disease. 
 
 This wasn’t the case with industrial trans fats, which are made by hydrogenating plant oils and are found in margarine and some processed foods like cake. The analysis suggests that eating more trans fat is associated with a 21 per cent rise in the likelihood of developing heart disease, and a 28 per cent rise in the risk of dying of this condition, confirming a number of other reviews that have linked trans fats to heart disease. 
 
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 Earlier this year, the US Food and Drug Administration banned the use of trans fats in food, giving manufacturers three years to comply. 
 
 “The results of this review support existing guidance to avoid industrially produced trans fats,” said Victoria Taylor, a dietician for the British Heart Foundation charity. “In the UK, industry action to remove these fats from manufactured foods means that our intakes are already below the recommended maximum of 2 per cent of food energy.” 
 
 The UK also advises that saturated fat makes up no more than 11 per cent of a person’s daily energy intake. 
 
 But de Souza’s results don’t necessarily mean it’s time to scrap this recommendation just yet. Although they were unable to find a link in their analysis, it is still possible that there might be one. Furthermore, sources of saturated fat may pose other health risks, says de Souza. 
 
 “There are many factors which cause coronary heart disease and no single food or nutrient is solely responsible for this,” said Taylor. “We will continue to recommend switching saturated fat for unsaturated fat, consistent with a traditional Mediterranean-style diet.” 
 
 Journal reference: BMJ, DOI: 10.1136/bmj.h3978.
– If nothing else can get you to cut back on trans fats, maybe the threat of death will do it. Researchers who analyzed 123 observational studies on saturated and trans fats published in the last 30 years found people who consumed a diet high in saturated fats saw no increased risk of ischemic stroke, Type 2 diabetes, coronary heart disease, cardiovascular disease, or death from all causes—though the certainty was "very low" and researchers say they may pose other health risks, per New Scientist. People who consumed a diet high in trans fats, however, saw a 34% boost in their risk of death from any cause, a 21% increased risk of CHD, and a 28% higher risk of death from CHD, per a press release. They found no link between trans fats and ischemic stroke and couldn't confirm an association between trans fats and Type 2 diabetes based on inconsistencies in the studies reviewed. Saturated fats generally come from animal products, like butter, meat, and egg yolks, and some plant products, like chocolate and palm oils. "Ruminant" trans fats also occur naturally in some of those foods. But it's the "industrially produced" trans fats in margarine and processed food that consumers should limit, lead author Russell de Souza tells LiveScience. Made from plant oils, these fats—to be phased out within three years—are more harmful. However, "there is no one nutrient or food that's responsible for all heart disease, diabetes, or death," de Souza says. "The whole diet matters." That means when cutting back on fats, people should be careful not to replace them with other poor choices, like sugars and starches. Instead, choose fruits and vegetables, whole grains, beans, peas, nuts, and unsaturated fats like olive and canola oils, de Souza says. (You might also want to steer clear of Southern food.)