By Destiny Uko
Palm oil is one of the most commonly used cooking oils in Nigeria and across many parts of Africa. Its unique taste and affordability make it a staple in countless homes and street food settings.
However, while fresh palm oil has some nutritional benefits when used in moderation, its repeated heating, especially during frying, poses serious and often overlooked health risks. Many households and food vendors reuse palm oil multiple times without understanding the potential dangers that come with this practice.
According to the World Health Organisation (WHO), repeated heating of oils can contribute to poor heart health and an increased risk of non-communicable diseases. The longer palm oil is exposed to heat, the more it degrades and undergoes chemical changes.
Reheating palm oil repeatedly not only diminishes its flavour and nutritional value, but it also causes the formation of harmful substances such as trans fats and polymerised triglycerides.
These substances are not only toxic to cells, but they have also been linked to several long-term health issues, including cancer, cardiovascular diseases, liver damage, and chronic inflammation.
Another concern with reused palm oil is its potential to cause liver stress. The liver is responsible for detoxifying harmful substances from the bloodstream. When a person consistently consumes food fried in reused oil, their liver is burdened with clearing out harmful compounds, including peroxides and aldehydes.
For those trying to maintain a healthy weight or manage diabetes, repeatedly heated palm oil presents another set of problems. The degradation of oil generates compounds that interfere with insulin sensitivity and metabolic regulation.
It is also worth noting that palm oil, when repeatedly heated and stored improperly, can become a breeding ground for bacteria and mould, especially if the container is not airproof or is exposed to moisture.
This micro-growth, combined with chemical degradation, increases the chances of food poisoning and other underlying issues. Many food vendors store their used oil for days, even weeks, without proper knowledge of how dangerous it becomes with each reuse.
Children, the elderly, and people with weakened immune systems are especially vulnerable to the health consequences of consuming food fried in reheated palm oil.
Their bodies are less equipped to handle the buildup of toxins and inflammation, making them more likely to suffer adverse effects. Despite this, children frequently consume such oils through street snacks and fried foods commonly sold in schools or by roadside vendors.
One effective way out is to use smaller portions of oil and fry in smaller batches. This minimises the temptation to reuse large amounts of oil repeatedly. When cooking in controlled, smaller portions, the oil is less exposed to prolonged heat, making it safer overall. It also allows the household to start fresh more often without necessarily spending more.
Households and food vendors can also switch to shallow frying or pan searing instead of deep frying. Shallow frying uses much less oil, reduces overheating, and still delivers crisp textures for foods like plantain, fish, or yam.
Not only is this method more oil-efficient, but it also limits exposure to toxic compounds that develop at deep-frying temperatures.
Introducing the natural oil-cleansing practice of filtering oil through clean muslin cloth can help maintain cleaner oil for slightly longer use. While this does not reverse oxidation, it removes visible impurities that cause spoilage and smoke production. These traditional techniques, when done hygienically, can support safer reuse within a limited timeframe.
For households with limited resources, rotating between different types of cooking methods such as boiling, steaming, or oven-baking can reduce dependence on deep-frying altogether. Using oil only once or twice for frying and then repurposing it for non-frying cooking instead of continued frying is also advised.
Another solution lies in community awareness. Many people simply do not know the science behind oil degradation. Schools, religious centres, and health workers can play a vital role in educating families, especially mothers and food vendors, on the importance of safer cooking habits.
The Nigerian Heart Foundation and the Nutrition Society of Nigeria are two organisations currently working to promote heart-healthy diets and food safety practices across the country.
Consumers can also begin to demand healthier practices from food vendors. Asking how often oil is changed or opting for vendors who fry with fresh oil may not always be possible, but it sends a message. The more health-conscious decisions people make collectively, the more likely vendors will adapt.
With food prices soaring, reusing oil may seem like a cost-saving solution. But the hidden health risks can be far more expensive in the long run.
Palm oil, a staple in Nigerian and African cuisines due to its unique taste and affordability, poses health risks when reused or overheated. The repeated heating of palm oil is linked to the formation of trans fats and polymerised triglycerides, which can lead to serious health issues such as cancer, cardiovascular diseases, liver damage, and chronic inflammation. The World Health Organisation (WHO) has noted the negative implications of this practice on heart health and the risk of non-communicable diseases. Moreover, reused oils can stress the liver and interfere with metabolic regulation, posing additional risks for those managing diabetes or weight issues.
To mitigate these risks, it is recommended to use smaller portions of oil, employ cooking methods like shallow frying or pan searing that require less oil, and utilize oil-cleansing practices like filtering through muslin cloth. Households can also reduce dependence on deep-frying by rotating cooking methods such as boiling, steaming, or baking. Education on the science of oil degradation through community awareness initiatives by schools, religious centers, and organizations like the Nigerian Heart Foundation can further guide safer cooking habits.
Consumers are also urged to demand healthier practices from food vendors, potentially leading to a shift towards safer cooking practices. While reusing oil may seem cost-effective amid rising food prices, the long-term health risks and subsequent expenses highlight the need for safer alternatives.
