Food health scares come and go. After being demonised for decades, butter is gaining a reprieve but palm oil looks set to take its place as the next ‘baddie’.
Palm oil facts
Palm oil is derived from the reddish pulp of the fruit of the African and American oil palms. Crude palm oil is red due to its high content of antioxidant carotenoids, alpha-carotene, beta-carotene and lycopene, but these are removed during processes that refine, bleach and deodorise the oil.
Palm oil is one of the few highly saturated, vegetable fats that is semisolid and creamy at room temperature, rather than forming a liquid oil. It is also highly resistant to oxidation, which gives it a long shelf life before turning rancid. This makes palm oil a popular ingredient in everything from lipstick, soap and shampoo to ice cream, chocolate spreads, pizza dough and baby milks.
According to the World Wildlife Fund (WWF), palm oil is now the most widely consumed vegetable oil on the planet and is in around half of all packaged products on sale in your local supermarket.
Palm oil health benefits
From a nutritional point of view, palm oil contains less saturated fat and more monounsaturated fat than butter which, for those who still believe that saturated fats are ‘bad’ is a good thing.
Palm oil health risks
The reason palm oil regularly attracts negative press is down to the way it’s processed. In their natural state, many fats and oils have strong flavours and odours. These oils are reduced by refining to make them more palatable in foods. When not done properly, this refining can generate substances known as glycidyl fatty acid esters (GEs) if temperatures are allowed to rise above 200oC. A joint statement from the FAO and World Health Organisation has directly associated GE formation with oils heated to elevated temperatures of over 240°C for extended periods of time.
Manufacturers know this and high temperatures are not used to process edible oils. While palm oil contains more of the types of fat (diacylglycerols) from which GEs can be generated, palm oil is carefully deodorised at temperatures that are kept below 200oC and at low pressure. This lower temperature processing still removes the natural red colour of palm oil and neutralises its smell but minimizes the production of GEs.
Are levels of GEs in palm oil a threat to health?
When GEs are digested, a breakdown product called glycidol is released which has been identified as a carcinogen when fed in very high doses to rats. The International Agency for Research on Cancer (IARC) has classified glycidol as a possible carcinogen in humans but this is not conclusive. At present, there is no robust scientific evidence linking exposure to GEs with cancer in humans at levels found in the normal diet.
A risk assessment carried out by the European Food Safety Authority in May 2016 found that the already low levels of GEs in palm oils and fats halved between 2010 and 2015, contributing to an important fall in consumer exposure.
They concluded that GEs could be a potential health concern for consumers with high exposure – especially for babies fed solely in infant formula, for whom the level of risk was ‘up to ten times what would be considered of low concern for public health’.
They were unable to draw firm conclusions about safe levels of intake for the rest of us but did state that the main sources of exposure to GEs in vegetable oils and foods was from eating margarines, pastries and cakes.
The World Health Organization and Food and Agriculture Organization of the United Nations then carried out a safety assessment on food additives in November 2016. They determined that the level of glycidol at which adverse effects were observed in animal studies was 2.4mg per kilogram body weight. Compared with this, estimated average dietary intakes of glycidol for adults were twelve thousand times lower at 0.2 micrograms per kilogram body weight per day.
They also estimated intakes for people eating a very unhealthy diet, full of processed foods, who would have the highest level of exposure to GEs. Even in the worst possible diets, the estimated dietary exposure to glycidol was at least three thousand fold lower than the potentially harmful level for adults, and 1,100 to 6,000 fold lower for children. For infants fed formula milks, the highest level of GE exposure was between 490 fold and 8,000 fold lower than the level identified as harmful in animal studies.
So, compared with many other risks in life, the relative risk of eating normal amounts of products that contain palm oil is small. You are highly unlikely to get cancer from the level of palm oil found in a varied, healthy diet (or even an unhealthy one, come to that). In fact, the chance is lower than that of an asteroid threatening life on Earth in 2032 – a risk that is currently estimated at around 1 in 14,000.
The key message from astronomers (and Douglas Adams) is ‘Don’t Panic’ and that applies to any scare stories you may hear about palm oil, too. If you want to minimise your intake of palm oil, then cut out the pastries and cakes that you already know you’re better off without, anyway. If you needed another reason to switch back from margarine to butter, feel free to go ahead.
Palm oil and sustainable production
Supermarket chain Iceland recently announced a plan to stop using palm oil in its own-brain products by the end of 2018 due to sustainability concerns. But to protect biodiversity the WWF is already working to ensure that palm oil is grown and produced sustainably. Many companies have already stepped up to score 9/9. You can check the sustainability score of your favourite palm oil containing brands here.
Image credits: pixabay