Intended for healthcare professionals

Feature Non-communicable Diseases

Trans fats: chasing a global ban

BMJ 2011; 343 doi: (Published 07 September 2011) Cite this as: BMJ 2011;343:d5567
  1. Rebecca Coombes, features editor
  1. 1BMJ, London WC1H 9JR, UK
  1. rcoombes{at}

They have been repeatedly called the “low hanging fruit” in global prevention of cardiovascular disease. But will this month’s New York health summit deliver the goods and help remove damaging trans fats from the world food chain? Rebecca Coombes reports

“You shouldn’t need to be a chemical engineer to buy healthy food,” says Steen Stender, the cardiologist from Copenhagen University Hospital who kick started a now global revolt against the addition of harmful fats to our daily diet.

What Professor Stender did was get industrial trans fatty acids, found in chemically modified vegetable oils that are hidden in numerous everyday foods, banned from the food chain in his native Denmark. All foodstuff, including imports, have now been free of industrial trans fats for seven years throughout the country.

“We haven’t discovered a change in the taste and prices have stayed the same,” says Professor Stender. “The bakers of Danish pastries were saying ‘they won’t flake in the same way’ with the new trans fat free recipes. But it just took one baker to find a way, and he then took out a big newspaper advert to tell everyone.”

After the Danes made it look so easy—consumers couldn’t tell the difference between the new Big Mac and the old ones—a string of countries and US states followed suit. But trans fats are still widely used around the world.

WHO therefore hopes that a ban on trans fats will be on the agenda at this month’s UN high level meeting on non-communicable diseases in New York. It has identified methods of tackling the rising levels of these diseases, which include cardiovascular disease and diabetes. Trans fats have been shown to lower levels of protective high density lipoprotein cholesterol and raise harmful low density lipoprotein cholesterol, increasing the risk of coronary heart events and strokes. They may also promote the development of diabetes.1

In 2004, WHO recommended that trans fats should comprise no more than 1% of total energy intake.2 Even low levels of consumption seem to be damaging: a 2006 US study found that an intake of 5 g of trans fats a day (around 2% of daily energy intake) was associated with a 23% increase in ischaemic heart disease.3

As an illustration of how easy it is to unknowingly consume trans fats, in 2006 Professor Stender and colleagues sampled fast food from 20 countries. The trans fat content of the foods—chicken nuggets and chips from McDonalds and KFC stores—varied by location, with the worst example being 24 g of trans fat in a KFC meal from Hungary.4 KFC and McDonalds have since eliminated trans fats from their food chains.

In Latvia, where rates of cardiovascular disease are among the highest in Europe, the most popular biscuit brand contains 12 g of trans fats in every 100 g. And in northern India, one of the most populous areas of the world, an artificial form of ghee that contains 50% trans fats (vanaspati) is found widely in street, restaurant, and hotel food.

In the UK, consumer awareness has forced many manufacturers to reduce the trans fat content of their products, and major supermarkets proudly proclaim that their own brand products are free of trans fats. But it is still possible to buy a takeaway on a UK high street containing high levels of trans fats. Recent estimates are that trans fats cause about 11 000 heart attacks and 7000 avoidable deaths in the UK every year.5

Drive for ban

If they wanted to, UN delegates in New York could agree on an enforceable global ban on trans fatty acids. But despite examples of success in Denmark, Iceland, Sweden, Austria, Switzerland, New York, and Brazil—to name just a few—a ban is unlikely, the BMJ understands. In fact, many European Union member states are engaged in furiously watering down any commitment to act against trans fats.

Simon Capewell, professor of clinical epidemiology at Liverpool University, sat on the National Institute for Health and Clinical Excellence expert group examining prevention of cardiovascular disease at population level. Last year the group called for trans fats to be removed from the UK.6

“I think that European countries have behaved scandalously in terms of watering down the process. The huge inertia about trans fats has been frustrating. You can have all those exemplar countries and yet the bulk of Europe still put up barriers.”

Professor Capewell says: “The food companies are trying to persuade politicians that eliminating trans fats is a big financial undertaking. Fortunately, the Swedes, Danes, and Fins are all sending big delegations to put the other side.

“Industrial trans fats are a low hanging fruit—here we have an identified, clear issue and spectacular example of success in several countries, especially Denmark, which shows it is not only simple and technically feasible to eradicate industrial trans fats but also politically viable. And it’s transferable to countries like Jamaica and Brazil. Okay, it’s now happening in enlightened high income countries, but the actual intervention is very low tech and low cost. It could happen anywhere.”

Walter Willetts, the Harvard epidemiologist who first documented the harmful effect of trans fatty acids on health in 1993, in an observational study on US nurses,7 is equally forceful on the need to act. “This is a food safety issue—until recently it’s been all microbial safety, such as E coli, but this is actually contamination.

“Industry is a very powerful force and there is a worry that it will try to muddy the waters at the summit. It’s like sugar. The US government directly intervened when WHO tried to tighten guidelines on sugar consumption.”

Industry action

Trans fatty acids are beloved of the food industry for their cheapness and convenience and are added to a variety of foodstuffs including bakery products, deep fried foods, snacks, sweets, and margarines. Cheap vegetable oils, commonly palm oil, are heated to very high temperatures and pumped with hydrogen gas, to create trans fats. This partially hydrogenated oil becomes solid when cooled, behaving more like animal fat, and adds texture to a wide range of foodstuffs, with the benefit of a long shelf life. Liquid products are also manufactured in a similar way for use in deep frying; the process prevents vegetable oils oxidising during frying and so preserves the taste.

But what’s good for the food industry is bad news for the consumer. The scientific evidence now clearly shows that even at low levels of consumption, trans fatty acids are harmful.3

The growing body of evidence has spurred a string of countries to follow the Danish example (see box). Some countries tried a more voluntary model, with mixed results. Canada and the US introduced mandatory labelling of trans fatty acid content in food. However, producers can label the food as “trans fat free,” even if it contains up to 0.5 g per portion. And portions can be small, just one biscuit. Furthermore, this approach lets non-packaged food, such as in restaurants, bakeries, and coffee shops, off the regulatory hook.

Kicking the trans fats

  • Denmark was the first country to ban industrial trans fats in 2003. The ban covered restaurants, coffee shops, small stalls, hospitals, cafeterias, and, crucially, all imports. European court action was launched against the Danes for impeding the free flow of trade, but in 2007 the action was withdrawn in the face of mounting evidence of harms caused by trans fats

  • Austria and Switzerland introduced similar bans in 2009

  • Canada and the US introduced mandatory declaration of trans fat and saturated fat content on food labels in 2003 and 2006 respectively. Some manufacturers reduced content as a result. However, a food can contain up to 0.5 g of trans fat “per portion” and still be labelled “trans fat free”

  • In 2008 New York legislated against trans fats in restaurants and the trans fat content of cooking fat fell from 50% to less than 2%.8 Other cities followed suit, including Seattle and Baltimore. California schools have gone fully trans fat free in the past year

  • UK, France, and Germany favour consumer pressure instead of mandatory labelling

  • Brazil, Argentina, Chile, and South Africa have all taken steps to reduce or eliminate trans fats from food

Labelling has had some success. As consumer awareness grew food giant Unilever, for example, removed trans fats from its margarine. But it took the example of New York City—and its wholesale legislative ban in 2008—to really get trans fats into terminal decline.8

Professor Willetts describes why a legislative ban in New York was so important for the rest of the US—it heralded societal change.

“I think change, such as with tobacco, comes from the ground up with a couple of individuals really pushing the agenda—and it’s essential you have the scientific data to back it up.”

He says we shouldn’t underestimate the “ripple effect” of local change. “The New York ban had that ripple effect, with national chains having to remove partially hydrogenated oils from all their kitchens. I guess we have eliminated 80% of trans fats in the US.”

Limitations of voluntary approach

The EU has been far slower then the US to deal with trans fats. This summer, it did tighten rules on food labelling, enforcing standardised information on saturated fat and salt content, for example, but did not include trans fats. Labelling won’t be revisited until 2014.

Professor Capewell is frustrated that leading European countries such as UK, France, and Germany are not doing more. He is scathing about the willingness of England’s health secretary, Andrew Lansley, to enter into “responsibility deals” with the food industry in the UK, including a “pledge” which promises no trans fats in processed foods by the end of this year.

“The model is just wrong—there will be voluntary agreements but there will be no independent monitoring. Industry will be able to do what it likes. Compared with legislation, voluntary action is weaker and much less effective,” he says, adding: “The UK line is ‘don’t worry, we’ve dealt with it.’”

There is some partial justification here: the Food Standards Agency estimates that mean trans fats intake for all adults [in England] is 1% of food energy, which sounds trivial but is still harmful. Furthermore, such average values hide the bigger effect on vulnerable groups at increased risk of coronary heart disease, such as ethnic minorities and young people in deprived circumstances for whom cheap takeaway food forms a key part of their diet.

“The problems with gradually removing something from food chain is that if it is legal and you can make money from it, then it will still happen. There will always be someone bringing in truck loads of microwave popcorn laden with trans fats to sell in the UK. Legislation really benefits the subgroups, those people who live on cheap food,” adds Professor Stender.

Even if trans fat consumption seems to be falling in wealthier European countries, a EU-wide ban could still save millions of lives. In eastern Europe for example, food high in trans fats is still plentiful in major supermarkets and fast food outlets.

Professor Capewell says there are parallels with the tobacco industry.

“After 50 years of successful industry obstruction, tobacco control has finally progressed to smoke-free legislation in many parts of the world—we are seeing this stepwise sort of process now rolled out in some low and middle income countries. So there are lots of parallels with tobacco, it’s just that trans fat is at an earlier stage.”

The one major difference with tobacco is that if you remove industrial trans fats from junk food, usually no one will even notice. “In Seattle, there was a post-[trans fats] ban survey and the public reaction was largely: ‘what took you so long?’” says Professor Capewell.

Professor Willett agrees that left to its own devices, industry won’t lead the way. It prioritises profit, not public health.

“We’ve known for a long time—15 years—that something should be done. Industry said there were no alternative oils to trans fats; farmers said we won’t plant the right seeds because there is no demand. But once manufacturers were required by law to put trans fat content on the label, it all changed.”

And none of the worse fears initially put forward by industry came to pass. “At first the industry party line was, we will just replace with saturated fat—but actually even that would be better than trans fat,” he said. In fact, the industry realised that this approach would also be unpopular with consumers and in most instances did not replace trans fat with saturated fat.

Even still, labelling is not enough. As Professor Stender puts it bluntly: “Instead of warning consumers about trans fats and telling them what they are, we’ve [the Danes] simply removed them. As they say in North America: ‘You can put poison in food if you label it properly.’”

Although things may be changing in the US, other parts of the world are not seeing similar success. Professor Willett says, “Unless there is a proactive effort in some Eastern European countries, South Asia, Middle East, things are not going to happen. They are too disconnected from success elsewhere. For example, major producers in India are not going to change unless there is strong resistance [to trans fats] from consumers. Word is getting out [among consumers] in India as an epidemic of type 2 diabetes starts to affect the population.”

Corinna Hawkes, visiting fellow at the Centre for Food Policy, City University, London, who formerly worked for WHO, agrees that although trans fats are well on the radar screens of the food industry, the story is far from over, particularly in low to middle income countries with low consumer awareness.

”Setting targets on trans fats, let alone banning them, would not be popular. It is not just a question of the food industry—the countries and regions in which these companies are economically important are also likely to be against making promises.”

Given that big food companies in Western countries have already done a lot to remove trans fats it seems strange that they should be against legislation. But Dr Hawkes says the answer is to do with marketing.

“Product innovation and marketing are the life blood of the modern food industry—it is what creates competitive advantage, value, and therefore profit, for the companies.” Removing trans fats fits very well into this model in countries where consumers are likely to respond by buying more of the product or spending more money on that product, she adds. Companies can claim innovation—removing trans fats to differentiate products from those with trans fats, which immediately adds value to the product. And they can use it to market a product with a “trans fat-free” claim, which also adds value. But in countries where companies can’t get that added value because of consumers’ lack of awareness, it’s not worth their while.

The food industry holds huge sway at an international gathering such as the UN high level meeting, says Dr Hawkes.

“The food industry is a means of generating economic activity for a nation state. So it is clearly within the national interest for many countries to protect the global interests of their national industries. And of course, the balance between economic and health interests of member states depends on who is sent to represent the country at any UN meeting: the food industry is more able to sway a ministry with responsibility for economic development than for health, and the foreign affairs people dealing with these UN meetings may be closer to the economic development people than the health people in the way that they think and their perception of the interests they have to protect.”

A spokesperson for the Department of Health in England said the summit wasn’t “in any of the ministers’ diaries at the moment.”

Nevertheless, Professor Capewell remains optimistic about the upcoming UN summit and what it can realistically achieve.

“The summit will be very useful for rehearsing the scientific evidence—it will give prominence to the very solid scientific basis for removing trans fats. And let’s face it, we didn’t get the framework convention on tobacco in one week.”

View from the summit

These comments were taken from a meeting of various health stakeholders in advance of the UN high level meeting on non-communicable diseases, held in New York in July.

Tom Frieden, director of US Centers for Diseases Control and Prevention: “Artificial trans fat is another product that has made its way into our food supply. It increases bad cholesterol. It reduces good cholesterol. It’s worse than saturated fat. And it is possible as has been shown in this country [the US] to eliminate artificial trans fat and at the same time reduce saturated fat by 10-20%.”

Ruth Colagiuri, vice president of the International Diabetes Federation. “I would put my money on the population health approach to primary prevention. Tobacco control is an example of the population approach, as is the reduction of salt, fat and sugar, and the banning of trans fat. No reduction required. No social marketing required. This is the default option. This is the way of making healthy eating the default option.”


Cite this as: BMJ 2011;343:d5567


  • Competing interests: The author has completed the ICJME unified disclosure form at (available on request from her) and declares no support from any organisation for the submitted work; no financial relationships with any organisation that might have an interest in the submitted work in the previous three years; and no other relationships or activities that could appear to have influenced the submitted work.

  • Provenance and peer review: Commissioned; externally peer reviewed.


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