Is it Good Or Bad For You?
What is grapeseed oil?
Grapeseed oil is oil processed from the seeds of grapes, which are a byproduct of wine making. After the grapes for making wine are pressed, the leftover grape seeds are treated with various chemicals to extract the oil in the seeds to derive an edible grapeseed oil.
How is grapeseed oil made?
Practically all edible grapeseed oils are refined oils which involved the use of heat and chemicals during the extraction process. These are the steps:
The refining process removes most of the nutrients from the oil. However, many manufacturers prefer to produce refined oil as it is cheap to produce them in large scale. Since grapeseed oil is a refined oil, it has a moderately high smoke point (216oC) which is suitable for high-heat cooking like frying.
The refining process of grapeseed oil
Fatty Acid Breakdown:
Omega-3: Omega-6 ratio = 1 : 23
Provide vitamin E
It is important to note that the harsh refining and solvent extraction processes can remove vitamin E from the grapeseed oil. To harness the health benefits of vitamin E, do make sure the grapeseed oil you purchase is fortified with vitamin E. Vitamin E serves as a fat-soluble antioxidant to help reduce oxidative stress in the body1,2. Moreover, vitamin E also helps protect the fat in the oil against oxidation3.
Excessive amounts of omega-6s
Omega-6s are essential fatty acids that the body need for growth and development. However, your body only requires a small amount and a healthy balance of omega-6 and omega-3 fatty acids is important. Excessive consumption of omega-6s and a high omega-6 to omega-3 ratio could promote inflammation which may lead to health problems such as cardiovascular disease, cancer, etc.
Unfortunately, grapeseed oil is a rich source of omega-6s and has a high omega-6 to omega-3 ratio. Since the majority of people are already consuming high amounts of omega-6 but insufficient omega-3s in their daily meals, routine consumption of added fats rich in omega-6 is not ideal. Considering very few people (especially children and the elderly) consume enough omega-3s (DHA & EPA) in their daily meals, choosing oils that are high in omega-3s such as flaxseed oil and camelina oil are the preferred and recommended choice for the whole family.
Contain more trans fat
Trans fat is bad for your health. It increases your risk of developing heart disease, stroke and type 2 diabetes. In a recent laboratory test, researchers found that edible grapeseed oil contains more than 1% trans fats before heat exposure. Exposure to 240°C heat produced even more trans fats. Compared to 9 other cooking oils, grapeseed oil contains the most trans fats both before and after heat exposure. The graph below shows the comparison between different cooking oils for trans fats formation5:
Low oxidative stability
Grapeseed oil was found to have lower oxidative stability than 9 other oils – extra virgin olive oil, virgin olive oil, olive oil, canola oil, avocado oil, rice bran oil, sunflower oil, peanut oil and coconut oil. When these cooking oils were heated to a temperature of 180°C, grapeseed oil contained more polar compounds (oxidative products) than any other oils at the one-hour point as illustrated in the graph below5: