Cooking oil: Which one should you use?

Olive oil is rich in monounsaturated oleic acid, a fatty acid believed to have many beneficial effects. PHOTO | COURTESY |

What you need to know:

  • Cooking with oils is a big part of many recipes and adds flavour to your dishes. But navigating which oils are best for your health can be a challenge.

When cooking at a high temperature, you must use oil that is stable and will not oxidise easily since when oils undergo oxidation, they form free radicals and compounds which are harmful to your health.

According to Amanda Twebaze, a nutritionist, the oil’s ability to resist oxidation is determined by the relative degree of saturation of the fatty acids in it.

Safe cooking tips

If one must have a safe meal prepared using cooking oil, it is important to learn the characteristics of the fat you are using for cooking. Animal and plant oils have different properties.

Characteristics such as melting point, ability of the fat to prevent food from sticking in the pans, the temperature at which the oil will begin to emit smoke after heating and the chemical reactivity since fats can be oxidised by air at high temperatures, which damages the flavour and lead to some health issues.

“It is vital that the food stays warmer than the melting point of the fat, or the emulsion will break, leaving you with two nasty layers rather than a creamy sauce. Add the fats after most of the cooking is done,” says Twebaze.

Regardless of the type of oil you use, oil is nutritionally classified as fat. Fats are more calorie-dense than carbohydrates or protein. Therefore, it is important to use it sparingly.

When you buy many different varieties of oil for different recipes, then store them for long periods in your kitchen, the oils oxidise over time and develop free radicals. Instead, buy just a few kinds of oil in small amounts and store them in a cold, dry place.

“Old oil is a harbour for free radicals. It is important to note that cooking oil should be used only once and if you are cooking at a high temperature or for a long time, use saturated fat,” says Twebaze.

Plant-seed oils

One can use oils from seeds and nuts such as palm oil, coconut oil and sunflower seed oil for food preparation instead of butter and margarine.

“The oils mentioned have lots of unsaturated fat, which is a healthy fat that protects one from heart diseases, high blood pressure and diabetes. They also contain vitamin E, an anti-ageing and an anti-inflammatory nutrient. Olive oil, avocado oil and coconut oil are ranked healthy in that order,” Twebaze says.

These oils are best for light frying, stewing sauces, basting foods in the oven, lining baking tins, an alternative to butter in some baking recipes and salad dressings, among others.

Coconut oil is your best choice when it comes to high heat cooking. Over 90 percent of the fatty acids in the oil are saturated, which makes it resistant to heat. The oil is semi-solid at room temperature and it can last for months and years without going rancid.

Lilian Nyanzi, a nutritionist, says although there are many nut oils, available, these are rich in polyunsaturated fats, which make them a poor choice for cooking. They can be used as parts of recipes, but they should not be used to fry or do any high heat cooking.

Olive oil helps lower bad cholesterol levels because of its antioxidant and anti-inflammatory properties which lower the risk of cardiovascular diseases.

“A diet rich in olive oil, low in saturated fats, moderately rich in carbohydrates and soluble fibre from fruit, vegetables, pulses and grains is the most effective approach for diabetics. It helps lower “bad” low-density lipoproteins while improving blood sugar control and enhances insulin sensitivity,” Nyanzi says.

“Although olive oil has been recommended as a good fat, it is important to watch how much fat you consume. Therefore, cook with less oil than a recipe calls for. Alternatively, you can use an olive oil spray to help you control the amount of oil you use. While baking, you can use half the oil to cut back on some fat and calories,” Nyanzi warns.

Butter vs ghee 

Butter is one of the commonest dairy products made from churned milk, salt and food colour. It is often used at room temperature as a spread, melted as a condiment and used as an ingredient in baking, sauce making, pan-frying, and other cooking procedures.

It is high in saturated fat and calories. For this reason, Twebaze recommends one to use butter in moderation or replace it with healthier options.  

Some people may think that ghee is a better option but Nyanzi says ghee and butter are both derived from cow’s milk and their nutritional profiles and fat content are similar.

“Ghee is made by melting unsalted butter. Upon heating, the butter separates into liquid fats and milk solids. The milk solids are then removed to remain with the liquid fat. When cooled, this forms ghee. However, ghee has a higher boiling point and lesser lactose levels than butter,” she says.

She adds that all fats that take a solid form at room temperature are saturated fats and are considered unsafe for use and unhealthy for the heart because they are high in cholesterol.

“Cholesterol results in clogging of the blood vessels and delicate organs such as the heart, which blocks blood and oxygen supply leading to cardiovascular diseases and strokes,” Nyanzi says.