Seed oils such as canola and corn oils have been touted as “heart healthy” for decades. Yet, recently you may be hearing that seed oils may not be as good as we were lead to believe. Let’s delve into this and clear things up.
What Are Seed Oils?
Seed oils are oils that have been extracted from plant seeds. Some examples of seed oils include:
- Sunflower oil: Extracted from sunflower seeds, it is commonly used in cooking due to its mild flavor and high smoke point.
- Soybean oil: Made from soybeans, it is one of the most widely consumed cooking oils in the world. It is often used in frying, baking, and salad dressings.
- Canola oil: Derived from rapeseed, canola oil has a neutral flavor and a high smoke point.
- Corn oil: Extracted from corn germ, it is commonly used for frying and in salad dressings. Commonly used in Latin American cuisine.
- Cottonseed oil: Produced from the seeds of the cotton plant, it is used in cooking and is a big ingredient in some margarines.
- Sesame oil: Made from sesame seeds, it is commonly used in Asian cooking for its distinct nutty flavor.
- Grapeseed oil: Extracted from grape seeds, it has a high smoke point and is often used in salad dressings and for sautéing.
Why Seed Oils Are Not as Healthy as We Thought
- High in Omega-6 Fatty Acids: Seed oils are rich in omega-6 fatty acids, which, in excess, can promote inflammation in the body. While omega-6 fatty acids are essential in small amounts, the modern diet often includes too many of them, leading to an imbalance with omega-3 fatty acids, which are anti-inflammatory. This imbalance is linked to various chronic conditions, including heart disease, obesity, and inflammatory diseases.
- Highly Processed: Most seed oils undergo extensive processing, which involves refining, bleaching, and deodorizing. These processes often use high heat and chemical solvents, which can strip the oils of nutrients and introduce harmful compounds, such as trans fats, even in small amounts. Trans fats are well-known for their negative impact on heart health.
- Oxidation: Seed oils are more prone to oxidation, especially when exposed to heat, light, or air. Oxidized oils can produce harmful free radicals, which can damage cells and contribute to aging, inflammation, and the development of chronic diseases.
- Potential Contaminants: The industrial processing of seed oils can introduce harmful chemicals, including hexane (a solvent used in extraction), which may leave residues in the oil. There is also concern about pesticide residues from the seeds used to produce these oils, especially if they are not organic.
- Altered Fat Composition: The process of hydrogenation, often used to increase the shelf life of seed oils, can create unhealthy trans fats, which are associated with an increased risk of heart disease, stroke, and type 2 diabetes.
In summary, seed oils are less healthy due to their high omega-6 content, extensive processing, susceptibility to oxidation, potential contaminants, and the presence of trans fats. For these reasons, I recommend limiting seed oil consumption and opting for healthier fats like olive oil, avocado oil, or other minimally processed oils such as coconut oil.
