This week on PLOS TGH – chewing the fat on all things trans fats, with Dr Luke Allen of the University of Oxford.
The European Parliament has adopted a resolution that seeks to ban the use of trans fats across the EU. Authorities in the United States have recently taken steps to eradicate trans fats and there is growing appetite for a global ban. So what are trans fats and why do we need them gone?
Let’s start with some facts about fats. Saturated fats can raise LDL (‘bad’) cholesterol and are widely considered to be detrimental to health. By contrast unsaturated fats are an essential component of a healthy diet and can reduce the risk of heart disease. Trans fats are a form of unsaturated fat but, gram-for-gram, they are one of the most dangerous nutrients known to man. Consuming as little as 5g per day (about half of a biscuit) increases the risk of heart disease by a staggering 23%. Trans fats are not required in the human diet and they offer no nutritional value. Removing them from the human food supply is both an urgent public health priority, and a relatively ‘quick win’ in a world where cardiovascular disease is the leading cause of death.
There are two sources of trans fats: the first is bacteria that live in the stomachs of ruminant animals including cattle, sheep, goats, and giraffe. They produce small amounts of trans fats that get into milk and meat products from these livestock. Naturally occurring trans fats do not seem to be damaging to human health.
The international furore surrounds the second form: industrially-produced trans fats. These are mainly found in partially hydrogenated vegetable oils (PVHO) and are made by heating vegetable oils with the addition of hydrogen.
Industrially produced trans fats were originally used as a cheap alternative to butter. They offer a number of culinary benefits including solidity at room temperature, long shelf-life, good ‘mouth-feel’ and a delectable flakiness. Healthier alternatives do exist but tend to be more expensive.
Artificial trans fats are found in biscuits, cookies, cakes, pastries, caramel, popcorn, frozen pizza, and fried food. The exact amount of trans fat in a particular product varies by manufacturer and by country. A study in the NEJM found that the amount of trans fat in a standard KFC meal varied across European countries from 1g to 25g per meal, which is literally a heart attack in a bun.
No one disputes that trans fats are harmful and should be removed, but there is disagreement about exactly how to do it. I think there are three main policy options:
1) Banning all foods that contain trans fats at anything other than negligible levels;
2) Labelling trans fats in packaged foods so that informed consumers can choose healthier options;
3) Asking industry to voluntarily reformulate their products.
Health ministers have already clashed over this issue at a meeting in Luxembourg. Differing worldviews, risk thresholds, and values play a role in determining which way to proceed.
A ban would be best
I subscribe to the view that public health is about improving the well-being of all and in particular, the worst-off first. Both labelling and voluntary efforts have led to large reductions in trans fat intake in certain countries but these approaches tend to disproportionately benefit the wealthier.
This is because labelling only helps those who can read, take the time to read nutrition labels, and can correctly interpret and apply the information contained therein. That excludes large swathes of the population, especially those who speak other languages or have not received a high level of education. Labelling trans fats can actually widen socioeconomic health inequalities. Another reason that I don’t like this approach is that the government has to spend money on public health campaigns urging people to choose healthier alternatives. We no longer do this for leaded paint or asbestos in many countries because consumers don’t have the option of buying these lethal products in the first place.
Banning trans fats outright removes the choice to consume a hazardous ingredient. Whilst this curtails a personal freedom, there is actually no discernible difference between foods laced with trans fats and their healthier, reformulated doppelgangers. Die-hard libertarians may froth at the mouth, but trading an academic right to self-poison (a choice that is only deliberately made by a tiny minority) for substantial health gains benefitting all is a bit of a no-brainer. The US government estimates that their ban on PVHO will save 7,000 lives and prevent 20,000 heart attacks every year.
The UK and the Netherlands are the only two countries to have seen real success with the voluntary approach. Their governments have politely asked industry to stop using trans fats, and by one important measure – mean population intake – this has worked. The average person in both countries now consumes less than the WHO recommended limit, however certain subgroups of the population still breech WHO limits. Again, it is low-income groups who remain at highest risk.
The Danish were the first movers with trans fats and I like their approach. They started with the less restrictive options but when they found that not everyone in society was benefitting from these measures they adopted a straightforward ban. Now everyone is protected and the most benefit is conferred to those who were previously consuming the highest amounts.
Canada tried something similar and laid down an ultimatum that if industry couldn’t eliminate trans fats on its own then a legal limit would be introduced. Despite encouraging progress in many areas there is still too much trans fat in Canadian food. The government has hitherto defaulted on its promise to introduce a ban, much to the chagrin of health campaigners.
Bans are undeniably heavy-handed, but these approaches are proportional to the risk involved and guarantee that everyone in society is protected from a dangerous and poorly understood substance.
The European Commission needs to complete an impact assessment before the Parliament’s vote to ban trans fats can be taken forward, but it is likely that a union-wide ban will be introduced. I have been lobbying for a global ban as this would present all manufacturers with the same reformulation costs, increase the availability of healthy replacement fats, and harmonise global markets. Most importantly a ban would prevent millions of deaths around the globe. Momentum is building and although there is a long way to go, the sun is setting on this cheap additive that is delicious and deadly.
Dr Luke Allen is a physician and global health policy researcher at the British Heart Foundation Centre on Population Approaches for Non-Communicable Disease Prevention. His interests include upstream health strategy and socioeconomic equity.