Seed oils are plant-based cooking oils derived from the seeds of various plants. They are typically found in processed foods such as burgers, fries, and packaged processed foods in stores. Because of how seed oils are produced, they often lead to inflammation and disease in the body.
Which seed oils can be unhealthy?
The seed oils below can be considered unhealthy and contain high omega-6 fatty acids. Omega-6 fatty acids are essential polyunsaturated fats important to heart and circulatory health. However, an overabundance of them can create dysregulation in the body.
- Canola oil (rapeseed oil)
- Corn oil
- Cottonseed
- Grapeseed oil
- Soybean oil
- Sunflower oil
- Safflower oil
- Rice bran oil
- Peanut oil
American diets typically already include too many omega-6s1. This throws off your body’s ratio of omega-6 fatty acids to omega-3 fatty acids (derived from various fish and cod liver oils), leading to inflammation.
Seed oils and inflammation
The problem with most seed oils is that they undergo a refining process. This process includes bleaching and deodorizing to improve the taste, color, and shelf life, but it also removes the oils’ antioxidants. In small amounts, the omega-6 fatty acids contained in seed oils can be beneficial, but the levels, combined with the refining process, make them potentially toxic.
Excessive consumption of seed oils has been linked to various diseases and chronic illnesses:
- Arthritis
- Heart disease
- Metabolic syndrome (a cluster of risk factors linked to cardiovascular disease such as high blood pressure, obesity, impaired fasting glucose)
- Stroke
- Type 2 diabetes
Carcinogens
Carcinogens are substances that may increase your risk of cancer. Though over 100 types of carcinogens2 from different sources, UV rays from the sun, chemicals such as asbestos, and substances like alcohol, they can also be found in ultra-processed foods. Furthermore, some foods, such as seed oils, can become carcinogenic or toxic when cooked in high heat. Even healthy alternatives to seed oils can also become harmful if heated beyond their smoke point.
These substances deregulate the body by changing your DNA, which triggers a chain reaction, turning normal cells into cancerous cells. Carcinogens alter how your cells multiply, grow, and mutate.
Carcinogens can build up in the body over a long period. It can be years or decades before they trigger a chain reaction that causes cancer. Fortunately, there are ways you can prevent this from happening with some lifestyle changes.
Avoiding seed oils and carcinogens
Eliminating seed oils and carcinogens from our environment may not be realistic. At home, you can make some simple changes:
Replace seed oils with extra virgin olive oil for low-heat cooking at home and avocado oil for high-heat cooking. Cooking with the right oil at the right temperature will prevent the oil from losing antioxidants.
Minimize your consumption of processed foods. Due to their high levels of omega-6 fatty acids, processed foods are one of the largest sources of toxic seed oils. Check the labels of processed foods and avoid those with high omega-6 content. The adequate daily intake of omega-6s is 17 grams for males and 12 grams for females ages 19–503.
Purchase simple foods with clean ingredients. The more you can simplify your food intake at home and avoid high levels of seed oils, the more balanced your diet will be when you eat out.
Reduce your intake of red and processed meat. Red, processed, and cured meat can contain carcinogens. This is sometimes due to the hormones used in cattle farming and the high temperature at which these types of meat are cooked. Opt for lean poultry sources such as chicken, turkey, or white fish.
Limit alcohol intake. Alcohol produces carcinogens when it’s metabolized in the body and contains a known carcinogen, ethanol. In 2020, 4% of cancers were attributed to alcohol4. In the U.S., moderate alcohol intake means women do not have more than one drink, and men do not have more than two drinks per day4.
Avoid smoking. Smoking is one of the leading causes of cancer in the United States5. Smoking and second-hand smoke is a huge source of carcinogens. Speak to your healthcare provider if you need help quitting smoking.
Making just a few changes can help prevent cancer and chronic disease. If you’d like to learn more about making lifestyle changes to your diet and keeping the body balanced, contact our healthcare team today at compass@hoag.org or (949) 557-0951.
1 Clinic, C. (2024, April 30). Seed oils: Are they actually toxic? Cleveland Clinic. https://health.clevelandclinic.org/seed-oils-are-they-actually-toxic
2 Professional, C. C. M. (n.d.). Carcinogens. Cleveland Clinic. https://my.clevelandclinic.org/health/articles/25081-carcinogens
3 Robertson, R., PhD. (2023, May 19). Omega-3-6-9 fatty acids: A complete overview. Healthline. https://www.healthline.com/nutrition/omega-3-6-9-overview#omega-3-6-9-supplements
4 Alcohol use: Weighing risks and benefits. (2024, January 20). Mayo Clinic. https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/alcohol/art-20044551
5 Risk factors: tobacco. (2017, January 23). Cancer.gov. https://www.cancer.gov/about-cancer/causes-prevention/risk/tobacco
