15/09/2026
VEGETABLE OIL: IS IT REALLY AS HEALTHY AS WE HAVE BEEN TOLD?
Vegetable oil has been marketed for decades as a convenient, affordable, and “heart-friendly” cooking option.
It is packaged in attractive yellow bottles, often with pictures of corn, soybeans, or sunflowers, and promoted as a healthier alternative to traditional fats.
But the reality is more complicated.
Not all vegetable oils are the same, and the way an oil is processed, stored, heated, and consumed can make a significant difference to its quality.
LET’S BREAK IT DOWN
“VEGETABLE OIL” DOESN’T USUALLY COME FROM VEGETABLES
If you squeeze cucumber, cabbage, okra, or garden egg, will cooking oil come out?
No.
What we commonly call “vegetable oil” is usually produced from seeds and crops such as soybeans, rapeseed or canola, sunflower seeds, cottonseed, corn, and safflower.
Many of these oils undergo extensive industrial processing before they become the clear, neutral-tasting oils we see on supermarket shelves.
HOW REFINED VEGETABLE OIL IS MADE
1. Harvesting and storage
Seeds are harvested, transported, and stored before processing.
As with other agricultural products, poor storage conditions can contribute to deterioration, contamination, or oxidation. Depending on farming practices, pesticides may also be used during cultivation.
2. Crushing and heating
The seeds are cleaned, crushed, and often heated to help release the oil.
Heat, oxygen, and prolonged storage can contribute to oxidation. When oils deteriorate, compounds such as peroxides and aldehydes may form.
This is one reason cooking oil should not be repeatedly overheated or reused.
3. Oil extraction
Some oils are extracted mechanically, while others are produced using solvents such as hexane to extract more oil from the seeds.
Food-processing systems are designed to remove these solvents before the oil reaches consumers. However, people who prefer less processed foods may choose cold-pressed or expeller-pressed oils instead.
4. Degumming
The crude oil is treated to remove gums, phospholipids, and other substances.
5. Neutralisation
The oil may then be processed to remove free fatty acids and other unwanted compounds, improving its appearance, taste, and shelf life.
6. Bleaching
Despite the name, ordinary household bleach is not added.
Special absorbent clays are commonly used to remove pigments, impurities, oxidation products, and trace metals.
However, refining may also remove some naturally occurring antioxidants and beneficial compounds.
7. Deodorisation
Finally, the oil may be exposed to very high temperatures under controlled conditions to remove unwanted smells and flavours.
After all this processing, many of us take the oil home and heat it again to fry:
Plantain
Akara
Puff-puff
Chicken
Fish
Chips
And sometimes the same oil is reheated repeatedly.
This is where the concern becomes much greater.
THE REAL PROBLEM: OXIDATION AND REPEATED HEATING
Repeatedly heating cooking oil to very high temperatures can increase the formation of oxidation products, including aldehydes.
The more an oil is heated, cooled, stored, and reheated, the more its quality can deteriorate.
This is particularly important with deep frying.
Instead of simply saying:
“All vegetable oil is poison,”
a more responsible message is:
Reduce heavily processed and deep-fried foods, choose good-quality cooking oils, and avoid repeatedly overheating or reusing frying oil.
WHAT ABOUT OMEGA-6?
Many seed oils contain relatively high amounts of omega-6 fatty acids.
Omega-6 itself is not a poison. In fact, the body needs essential fatty acids.
The goal should be balance.
A healthy diet should also include sources of omega-3 fatty acids such as fish, nuts, seeds, and other whole foods while limiting excessive consumption of ultra-processed and deep-fried foods.
WHAT REALLY MATTERS?
Your overall eating pattern matters more than any single ingredient.
A diet dominated by:
Deep-fried foods
Ultra-processed foods
Excess sugar
Refined carbohydrates
Excess calories
Frequently reused frying oil
can contribute to poor metabolic and cardiovascular health.
Instead, focus more on whole foods, vegetables, fruits, legumes, whole grains, quality proteins, and appropriate amounts of healthy fats.
BETTER COOKING OPTIONS
1. Red palm oil – particularly traditional, minimally processed varieties.
2. Coconut oil – relatively heat-stable, but best used in moderation because of its saturated-fat content.
3. Avocado oil – suitable for higher-temperature cooking.
4. Butter – useful for certain dishes, in moderation.
5. Ghee – more heat-stable than regular butter.
6. Extra-virgin olive oil – excellent for salads, sauces, and many cooking applications.
7. Cold-pressed, locally processed groundnut oil – a good traditional option when properly produced and stored.
8. Tallow – traditionally used for cooking, although moderation is advisable because it is high in saturated fat.
THE BOTTOM LINE
Do not automatically assume that something is healthy simply because the bottle says:
“Vegetable oil”
“Cholesterol-free”
“Heart-friendly”
Read the label.
Know what you are eating.
Choose good-quality oils.
Avoid repeatedly reheating frying oil.
Reduce deep-fried and ultra-processed foods.
Eat more whole, natural foods.
The goal is not to fear food.
The goal is to understand what we are putting into our bodies and make better choices whenever possible.
Your health is one of your greatest assets.
Protect it.
YOU ARE WHAT YOU EAT.
