Warning: Reusing cooking oil twice could cause cancer

Things are hard, and the cost of living is climbing daily. Food prices have gone through the roof, and everyone is trying to make the most out of the little they have.

In many Nigerian homes, families are cutting back on expenses and managing resources like never before. One of the most commonly managed kitchen items is cooking oil. It’s not unusual to find people frying akara in the morning, using the same oil to fry plantain in the afternoon, and then reusing it the next day for fish before finally using it for stew.

Some even go as far as reusing cooking oil up to four or five times just to make ends meet. But the truth is, reusing cooking oil more than twice is dangerous, and it could lead to cancer. We're already doing our best to survive, but you shouldn't trade your health for it.

ALSO READ: Stop eating fufu if you value your life

Why Reusing Cooking Oil is Harmful

When cooking oil is heated repeatedly, it undergoes a chemical transformation. At high temperatures, especially during frying, oils start to break down. This breakdown process produces harmful compounds such as free radicals, acrolein, and polycyclic aromatic hydrocarbons (PAHs). These compounds are known to be carcinogenic, meaning they can cause cancer.

The more you heat the oil, the more these dangerous substances accumulate. If you're using oil that has darkened in colour, smells burnt, or has thick residue at the bottom, it is very dangerous!

YOU MIGHT LIKE: 14 powerful foods that cleanse your liver naturally

What Science Says

Several studies have repeatedly linked heated oil to different types of cancer. Here are some of the most concerning ones:

1. Breast Cancer: Studies show that reused cooking oil can disrupt hormones, which increases the risk of hormone-related cancers like breast cancer.

2. Colorectal Cancer: The presence of free radicals and toxic aldehydes in reheated oil can inflame and damage the lining of the intestine and colon.

3. Pancreatic Cancer: Acrolein, formed when oils are overheated, has been linked to cell mutations that increase the risk of pancreatic cancer.

4. Liver Cancer: The liver is responsible for filtering toxins from the body. Constant exposure to reheated oil can overwhelm the liver, leading to long-term damage and cancer risk.

A study published in the Journal of Clinical Biochemistry and Nutrition found that animals fed food fried in repeatedly heated oil had an increased risk of liver toxicity and cancerous changes in their organs.

RELATED: 9 everyday foods that are slowly destroying your liver

Visible Signs That Your Oil Is No Longer Safe

• Dark colour and thick texture

• Foaming or smoking quickly when heated

• Sticky residue at the bottom of the pot

• A sour or burnt smell

• If your oil looks or smells “off,” don’t just top it up with fresh oil; throw it away. It’s not worth the risk.

What Can You Do Instead?

• Use smaller quantities of oil when frying to avoid waste.

• Air fry, grill, or oven-roast when possible; these methods use little or no oil.

• Choose more affordable oils for single-use cooking. Palm oil, for example, has a higher smoke point and is less toxic when used correctly.

• Avoid deep-frying when unnecessary; boiling, steaming, and stir-frying are safer alternatives.

RECOMMENDED: 5 Nigerian soups that are good for your kidney

Using the same oil to fry different foods creates a toxic mix. The oil takes on the characteristics of each food item, making it more likely to oxidise and form dangerous chemicals during the next heating cycle.

Nigeria is tough right now; no one is denying that. But no matter how hard things get, your health should never be up for compromise. Reusing cooking oil more than twice is not managing, it’s risking cancer.

EXPLORE: If you have PCOS, avoid these foods