From the Guidelines
Consuming seed oils in moderation, as part of a balanced diet, is generally considered safe and may even have health benefits, particularly when they replace saturated fats. The most recent and highest quality study, published in 2022 in the journal Cardiovascular Research 1, found that replacing saturated fats with omega-6 polyunsaturated fats, which are abundant in seed oils, can reduce the risk of coronary heart disease (CHD) by 8-24%. Some key points to consider when consuming seed oils include:
- Balancing omega-6 fatty acid intake with omega-3 sources, such as fatty fish, flaxseeds, and walnuts, to minimize the risk of inflammation and related health conditions.
- Choosing high-quality seed oils that are extracted using minimal processing and without chemicals like hexane.
- Using seed oils in moderation and varying dietary fat sources to minimize potential risks.
- Considering the use of more stable cooking oils, like olive oil or avocado oil, for high-heat cooking to reduce the formation of harmful compounds. It's also important to note that the evidence on seed oils is not entirely consistent, and some studies have raised concerns about their potential health effects, such as promoting inflammation and oxidative stress 1. However, the most recent and highest quality evidence suggests that moderate consumption of seed oils, as part of a balanced diet, is unlikely to pose significant health risks and may even have benefits, particularly when they replace saturated fats. Overall, the key is moderation and variety in dietary fat sources, rather than complete elimination of seed oils.
From the Research
Health Risks of Consuming Seed Oils
The consumption of seed oils has been linked to several health risks due to their high content of omega-6 fatty acids. Some of the key risks include:
- Increased inflammation and oxidative stress: A high intake of omega-6 fatty acids can lead to an imbalance in the omega-6/omega-3 ratio, promoting inflammation and oxidative stress in the body 2, 3, 4.
- Cardiovascular disease: Excessive consumption of omega-6 fatty acids has been linked to an increased risk of cardiovascular disease, including heart attacks, strokes, and high blood pressure 5, 3, 4.
- Autoimmune diseases: The high omega-6 content in seed oils may contribute to the development of autoimmune diseases, such as rheumatoid arthritis, lupus, and multiple sclerosis 2, 6.
- Cancer: Some studies suggest that a high omega-6/omega-3 ratio may increase the risk of certain types of cancer, including breast, colon, and prostate cancer 4.
- Other chronic diseases: The imbalance of omega-6 and omega-3 fatty acids in the diet has also been linked to other chronic diseases, including type 2 diabetes, asthma, and allergies 2, 3, 4.
Mechanisms of Action
The health risks associated with seed oil consumption are thought to be mediated by several mechanisms, including:
- Imbalance of the omega-6/omega-3 ratio: A high intake of omega-6 fatty acids can lead to an imbalance in the omega-6/omega-3 ratio, promoting inflammation and oxidative stress in the body 2, 3, 4.
- Increased production of pro-inflammatory eicosanoids: Omega-6 fatty acids can be converted into pro-inflammatory eicosanoids, which can contribute to inflammation and oxidative stress in the body 6.
- Suppression of anti-inflammatory eicosanoids: A high intake of omega-6 fatty acids can also suppress the production of anti-inflammatory eicosanoids, which can further contribute to inflammation and oxidative stress in the body 6.