Millions of Cameroonians use refined vegetable oils for cooking daily, unaware of the potential health risks. Nutritionists are raising concerns about this common culinary habit in Douala, Yaoundé, and Bafoussam, where refined palm, soybean, or sunflower oil is prevalent.
The industrial refining process, involving high temperatures, destroys essential nutrients and generates toxic compounds. Scientific studies highlight the dangers of these oils. Research published in the British Medical Journal in 2013 revealed that individuals with heart disease who replaced saturated fats with sunflower or corn oil had an increased risk of cardiovascular mortality. A 2020 Harvard University study also confirmed that trans fatty acids, produced during high-temperature frying, promote chronic inflammation, a risk factor for type 2 diabetes, strokes, and certain cancers.
An imbalance between omega-6 and omega-3 fatty acids is a major concern. Refined vegetable oils are rich in omega-6, pro-inflammatory fatty acids. A balanced diet should ideally have an omega-6 to omega-3 ratio of 4:1. However, excessive consumption of these oils can raise this ratio to 20:1 or even 50:1, leading to chronic inflammation in the body.
In Cameroon, certain culinary practices exacerbate this problem. Deep and repeated frying, characteristic of popular dishes like ndolé, beignets, braised fish, and fried plantains, exposes consumers to increased risks. A 2017 study from the University of Algarve (Portugal) demonstrated that reusing vegetable oils heated above 180°C releases toxic aldehydes, such as 4-HNE, associated with neurodegenerative diseases like Alzheimer's and Parkinson's. Furthermore, the quality of oils sold in local markets is often questionable, with issues of mixing, inadequate storage, and exposure to heat and light, promoting oxidation and the formation of carcinogenic free radicals.
Statistics from the Ministry of Public Health in Cameroon are concerning. Cardiovascular diseases now account for nearly 30% of deaths in reference hospitals, and type 2 diabetes is increasing rapidly in cities. In 2020, coronary heart disease deaths reached 10,695, representing 5.97% of total deaths. A study conducted in a hospital in the South West region revealed that cardiovascular diseases accounted for nearly 16% of admissions, with women being more affected than men.
Given these risks, making informed choices about cooking oils is crucial. Nutritionists recommend limiting the consumption of sunflower, soybean, and corn oil for high-temperature cooking as much as possible, and never reusing oil that has already been heated. Some oils, such as olive oil, avocado oil, and coconut oil, are more stable at high temperatures. Prioritizing oils rich in monounsaturated or saturated fatty acids and low in polyunsaturated fatty acids can help reduce the formation of harmful compounds.
