From olive to flaxseed to grape seed, cooking oils are a staple in every kitchen. But, with so many varieties and brands crowding the grocery shelves these days, choosing the right oil can be tougher than you think!
There are two types of cooking oils based on the type of fat; those made up of polyunsaturated fats (e.g. sunflower, safflower, grape seed, flax and sesame oil) and those mainly comprised of monounsaturated fat (e.g. olive, peanut, and canola oil).
While both mono- and poly-unsaturated fats help lower cholesterol when substituted for saturated (animal) fat in the diet, some of these oils do so much more.
For instance, some polyunsaturated oils offer a greater advantage because they supply a high amount of an omega-3 fat called alpha-linolenic acid or ALA. Your body cannot make ALA on its own and studies suggest that people who have higher intakes of alpha-linolenic acid have a lower incidence of heart disease. Your best bets for this group of oils would be flax, walnut, and hemp oil.
Onto the monounsaturated oils; studies clearly show that not only does this group of oils help to lower cholesterol but they also boost good HDL cholesterol. Monounsaturated fat is also thought to improve the body’s use of insulin in people with type 2 diabetes.
As a monounsaturated fat, olive oil has by far received the most attention. Olive oil has natural phytochemicals that help to reduce inflammation in the body, prevent blood clots and help to lower blood pressure by dilating blood vessels in the body.
But not all olive oil is created equal, though! There are many differences between the olive oils on the grocery shelves. ‘Extra-virgin’ and ‘virgin’ olive oils are dark colored oils. These are by far the healthiest because they are cold-pressed from olives using no heat or chemicals that help to retain many of the nutrients and phytochemicals.
On the other hand, ‘light’ olive oil (light in color not in calories by the way) and plain old ‘olive oil’ have been refined and processed more which results in less of those health-promoting phytochemicals we find abundantly in extra-virgin olive oil.
Can heating oils change their nutritional value?
Yes; some of the healthiest oils can become less healthy when you heat them. All oils have what is called a ‘smoke point’ – the temperature at which the oil starts to burn and break down. Oils that can withstand high-heat cooking include peanut, canola, safflower, corn, and sesame oil.
Extra-virgin olive oil and virgin olive oil have a lower smoke point so you are better off using these in a salad dressing or marinade.
Flax, walnut, and hemp oils should not be used for cooking at all since the heat destroys the omega-3 fatty acids. Store these oils in your refrigerator and use only in salad dressings, smoothies, and marinades.
Andrea Hill is a registered nutritionist living on Grand Cayman; email [email protected]