The truth about oil5 min read . Updated: 26 Nov 2012, 09:12 PM IST
Consume a variety of oils, since each oil has different properties, and different benefits
Sunflower. Olive. Mustard. Sesame. Canola.
The sheer variety of oils your neighbourhood shop or supermarket puts on its shelves is probably increasing with each passing day. But in our kitchen, the story is a little different—most of us use “vegetable oil" for cooking just about everything, and at best, have started using olive oil. Even if you did want to experiment with oils, given the bad reputation they have you are probably unsure if it’s even desirable to consume more than one type of oil.
We all know that olive oil is good for you, but here’s the surprising truth—so are mustard, sesame, rapeseed, walnut and canola. The best thing is to consume a variety of oils, since each oil has different properties, and different benefits. Using a few different types of oils can help balance your intake of omega-3 and omega-6 polyunsaturated fats (Pufa), as well as saturated and monounsaturated fats (Mufa), all of which your body needs.
Saturated fats are typically solid at room temperature, and are mainly found in animal sources of food. This type of fat raises total blood cholesterol levels and low-density lipoprotein (LDL) or bad cholesterol levels, which can increase your risk of cardiovascular disease. Saturated fat may also increase your risk of type 2 diabetes and should be used sparingly. Mufas are healthy fats that may lower your total LDL levels but maintain or increase high-density lipoprotein (HDL) or the good cholesterol, which is why they are a central part of the Mediterranean, heart-friendly diet.
Pufas come in two varieties, omega-3 and omega-6, and both are essential for the body. The worst kind are trans fats, and though they can occur naturally in some foods, most are made during food processing through partial hydrogenation of unsaturated fats. While natural trans fats (that occur in milk and other dairy produce) are not harmful, synthetic ones, such as Dalda, and in some processed foods like biscuits, have been linked clearly to an increased risk of cardiovascular disease.
Your choice of oil also depends on how you intend to use it in the kitchen—some cooking methods not only destroy many of the nutrients but also turn the oil carcinogenic. Consider the “smoke point" of the oil you are using, or the temperature at which it begins to break down and deteriorate. A high smoke point means the oil is good for all types of cooking, a low one means it’s best uncooked—oils with smoke points below 177 degrees Celsius are low, and those with more than 210 degrees Celsius are high. Extra virgin olive oil, for example, has a low smoke point, so if you use it to cook something like a stir-fry where you need the oil to be really hot, you will not only lose the benefits of olive oil, it will also cause harm.
Here’s a quick low-down on some of the different types of oils (we’ll keep the much discussed olive oil out of this) and the pros and cons of their usage.
Rapeseed oil: It is a good source of both Mufa and Pufa. More importantly, it has one of the lowest contents of saturated fat among oils. The smoke point of rapeseed oil is high, and its taste neutral, so it’s best used in cooking.
Avocado oil: It’s higher in Mufa than olive oil, and is an important ingredient of the Mediterranean diet. It is also a good source of vitamin E. Its lovely nutty flavour makes it ideal for dressings. It has a higher smoking point than all plant oils, so it’s great for frying as well. It also contains lutein, an antioxidant shown to bolster eye health. It’s expensive and difficult to find in India, though gourmet or speciality food stores will carry such oils.
Flaxseed oil: Made from the seeds of the flax plant, this oil contains high levels of omega-3 and omega-6 fatty acids. It has a very low smoke point, so you cannot cook with it, but it does wonders as a salad dressing, or even whipped into a smoothie.
Canola oil: This oil possesses more heart-friendly omega-3 than olive oil, and also has one of the lowest levels of saturated fat of any dietary oil. It also has a high smoke point, so it’s ideal for cooking. When baking, you can replace one cup solid fat, like butter, with O cup canola oil. The drawback is that it’s a refined oil that’s low in antioxidants.
Hemp oil: Hemp’s dark green colour is due to its high chlorophyll content. Hemp is a rich and balanced source of omega-3 and omega-6, and its gamma linolenic acid (GLA) content makes it unique among plant seed oils. GLA has been shown to help maintain healthy cholesterol and blood pressure levels, and aids in hormonal balance. Hemp oil is not suitable for heating because of its low smoke point.
Grapeseed oil: A good source of both vitamin E and oleic acid, a fatty acid that may help slash your risk of stroke by up to 73%, according to a study published in the journal Neurology. It has a fairly high smoking point, so it can be used for cooking, but it lacks antioxidants.
Walnut oil: It has a toasty, warm flavour and is a great source of alpha-linolenic acid (ALA). Plant-based ALA has been known to lower the risk of type 2 diabetes. It is great for salad dressings because of its flavour and has a high smoke point too.
Mustard oil: Used traditionally in Bengali cooking, a recent study by the All India Institute of Medical Sciences and Sir Ganga Ram Hospital in New Delhi found that the oil is high in Mufa and Pufa, has both omega-6 and omega-3, and a high smoke point. One of the best oils to use for cooking, though its sharp taste is not for everybody.
Remember, whatever the choice of oil, it will give you at least 120 calories per tablespoon. Any more than 2.5 tablespoons of even the healthiest oil per day in your diet is not good for you. Measure the oil you are using with a tablespoon, instead of directly pouring it from the bottle, to have more control over its usage. Even better, use a spray bottle to spray a thin layer of oil evenly on your pan—this way, you will always end up using less than you usually do.
Though omega-3 and -6 are both beneficial, the ratio of 3:6 should be 1:1 in your diet. Unfortunately, most diets are rich in omega-6, but lack 3. Research shows that an excess of omega-6 can promote cardiovascular disease, auto immune diseases, even cancer. Omega-3, on the other hand, does exactly the opposite. Include more oils which are high in omega-3 in your diet.
Vishakha Shivdasani is a Mumbai-based medical doctor with a fellowship in nutrition. She specializes in controlling diabetes, cholesterol and obesity.