Palm oil – it’s an ingredient in an estimated 50% of all packaged foods in our supermarkets.
There have been lots of headlines about its destructive environmental impact, but much less is known about the health impact of eating palm oil. So, I decided to use my own body in an experiment to find out what palm oil is doing to our health in a documentary I made, Appetite for Destruction: The Palm Oil Diaries.
You’ve almost certainly eaten palm oil today. It’s in everything from bread, to biscuits, pizzas, ice cream, chocolate bars and ready meals. However, it’s a relatively new addition to our diet.
Before palm oil, food manufacturers used hydrogenated oils, known as trans-fatty acids, to give vital texture to food products. But trans-fatty acids suffered very bad publicity in the early 2000s and became seen as a very unhealthy ingredient.
This led to government rulings across the world that trans-fatty acids must be labelled on products that contained them. Inevitably this put consumers off buying products with this damaging label.
Food companies were left with a dilemma: they couldn’t use trans-fatty acids, but they needed an ingredient that would provide that smoothy, creamy taste their customers loved.
As Prof Bruce Griffin from the University of Surrey told me, “palm oil was introduced as a natural substitute for trans-fatty acids”.
Despite replacing an unhealthy ingredient, palm oil-producing countries have suggested palm oil is perfectly healthy. The Malaysian Palm Oil Council even suggests that studies show palm oil, in liquid form, is “comparable to the much touted gold standard olive oil for its effects on blood cholesterol”.
I wanted to see for myself whether palm oil is healthy or not. I contacted a team of researchers from the University of Uppsala in Sweden. They had been doing an experiment in which they compared the effects of eating palm oil with sunflower oil.
For seven weeks, participants ate muffins containing either palm oil or sunflower oil. The thirty-nine participants received muffins that were “identical with regard to energy, fat, protein, carbohydrate, and cholesterol content, as well as taste and structure”. The only difference was the oil – palm or sunflower.
Under the researchers’ guidance, I did my own version of the experiment that mimicked the official study. For six weeks, I ate three muffins a day containing palm oil on top of my normal diet.
At the start of the experiment I had a remarkably low body fat – just 4.6%. This was the result of doing lots of long-distance running, including running eight marathons in eight days for a previous documentary.
After six weeks I returned to Uppsala to be tested. Remarkably, my body fat had increased to 7.4%. That’s an increase of around 60%! In addition, my muscle mass has decreased and fat stores increased.
You may not be surprised that my body fat increased after eating three muffins – an extra 750 calories – every day for six weeks. However, what is most shocking is not the weight gain, but where the fat was gained within my body.
In the University of Uppsala’s controlled study they noticed that participants from both the palm and sunflower oil groups gained about 1.6kg in weight. However, the palm oil group gained “more liver fat, total fat, and visceral fat” than the sunflower oil group. This means the fat was gained around vital organs, which can be very dangerous in the long term.
David Iggman, one of the researchers, analysed my results and predicted that if I continued with a palm oil-rich diet, “according to these results, you could be at risk of developing metabolic disease, perhaps also liver disease and even cardiovascular disease”.
This certainly shocked me. I returned to the UK worried that we’re not seeing the whole story when it comes to palm oil. I started noticing in the supermarket that some companies are now labelling food products as palm oil free. However, this is not for health reasons, but an environmental pledge.
Take Meridian’s peanut butter, which has a banner on its packaging saying, “No palm oil!”. The banner is held up by a cartoon orangutan – an animal suffering from the deforestation caused by the expansion of palm oil plantations in South East Asia.
For my palm oil documentary, I visited palm oil-producing countries. The environmental destruction in Cameroon and human rights abuses in Guatemala I witnessed were appalling. And they’re driven by our massive consumption of palm oil.
I think we need to reconsider not only how we produce this oil, but also, given the health consequences, whether we should be eating so much of it in the first place.