What oils are not anti-inflammatory?

December 24, 2025 •

4 min read

Studies suggest that the modern Western diet's ratio of omega-6 to omega-3 fatty acids has shifted from an ideal 1:1 to as high as 20:1, which promotes chronic inflammation. This dietary imbalance is largely influenced by what oils are not anti-inflammatory and are instead high in omega-6s.

Quick Summary

Several common cooking fats and oils are not anti-inflammatory due to their high omega-6 content or high degree of processing. This includes corn, soybean, sunflower, and other generic vegetable oil blends used widely in processed foods.

Key Points

High Omega-6 Oils: Corn, soybean, sunflower, and generic 'vegetable' oils are high in omega-6 fatty acids, which can be pro-inflammatory when consumed in excess.
Refined Processed Oils: Many oils are highly refined, stripping them of beneficial antioxidants and potentially creating harmful compounds, especially under high heat.
Excess Omega-6 is Problematic: A dietary imbalance with too many omega-6s relative to omega-3s is a key driver of chronic inflammation in the body.
Choose Anti-Inflammatory Options: Healthier alternatives include extra virgin olive oil, avocado oil, and flaxseed oil (for cold use), which are high in beneficial monounsaturated or omega-3 fats.
Avoid Trans Fats: Partially hydrogenated oils found in shortening and margarine should be strictly avoided due to their links with increased cholesterol and heart disease.
Cooking Matters: Overheating any oil beyond its smoke point can cause it to break down and produce harmful free radicals, which are damaging to cells and promote inflammation.

The Imbalance of Omega-6 and Omega-3 Fatty Acids

To understand which oils are not anti-inflammatory, it's crucial to grasp the balance between omega-6 and omega-3 fatty acids. Both are polyunsaturated fats essential for bodily functions, but a healthy balance is critical.

Omega-3 fatty acids, found in sources like fish oil, flaxseed, and walnuts, are known for their potent anti-inflammatory effects. Conversely, omega-6 fatty acids are necessary in small amounts but, in excess, can be converted by the body into pro-inflammatory compounds. The typical Western diet relies heavily on omega-6-rich oils found in many processed foods, leading to an inflammatory state within the body.

Common Oils That Are Not Anti-Inflammatory

High Omega-6 Vegetable and Seed Oils

A large number of widely used vegetable and seed oils have high concentrations of omega-6 fatty acids and are not considered anti-inflammatory. They are often inexpensive and have a high smoke point, making them popular for high-heat cooking and processed food manufacturing.

Soybean Oil: One of the most commonly consumed oils in processed and fast foods. Its high omega-6 content is a major factor contributing to the modern dietary imbalance.
Corn Oil: Rich in omega-6 fatty acids, corn oil is a staple in fried foods and many packaged snacks. Heating corn oil to high temperatures can also produce oxidized fats that increase inflammation.
Sunflower Oil: While it contains Vitamin E, excessive consumption of high-omega-6 sunflower oil can contribute to inflammation. It's available in high-oleic acid varieties, which are healthier, but the standard versions are high in omega-6.
Safflower Oil: Similar to sunflower oil, high-linoleic safflower oil has a high omega-6 content, while high-oleic safflower oil is a better option.
Grapeseed Oil: Extracted from grape seeds, this oil is high in omega-6 polyunsaturated fats.
Cottonseed Oil: Often used in packaged snacks and fast foods due to its low cost and neutral flavor.

Highly Processed and Refined Oils

Highly refined oils undergo extensive processing involving heat and chemicals, which can strip away beneficial nutrients like antioxidants and leave behind harmful compounds. Generic "vegetable oil" is typically a blend of high omega-6 oils like soybean, corn, and cottonseed. Canola oil, though containing some omega-3s, is often highly refined, which can reduce its health benefits.

Saturated Fats and the Case of Coconut Oil

Saturated fats, found in animal products, palm oil, and coconut oil, can raise cholesterol levels and are often associated with increased inflammation. While coconut oil is a plant-based saturated fat, research on its inflammatory properties is mixed. One meta-analysis found no significant effect on inflammatory markers, but it did show an increase in cholesterol. For this reason, many health professionals advise moderation.

Comparison of Inflammatory vs. Anti-Inflammatory Oils


Feature	Anti-Inflammatory Oils	Inflammatory Oils	Recommendation
Fatty Acid Profile	High in monounsaturated (oleic acid) or omega-3 fats.	High in omega-6 polyunsaturated fats.	Prioritize oils with high MUFA or omega-3 content.
Processing	Minimally processed (e.g., extra virgin, cold-pressed).	Often highly refined using heat and chemicals.	Choose minimally processed options to retain beneficial compounds.
Heat Stability	Generally stable for cooking (e.g., avocado oil's high smoke point).	Some are less stable, producing harmful oxidized compounds when heated.	Match the oil's smoke point to your cooking method.
Antioxidants	Contains natural antioxidants like polyphenols and Vitamin E.	Refining processes remove most natural antioxidants.	Opt for oils that retain their antioxidants for cellular protection.

Actionable Steps for a Healthier Balance

To manage inflammation through dietary changes, focus on reducing your intake of omega-6-heavy oils and increasing omega-3 consumption. Here are some simple steps:

Read Labels: Check ingredient lists on packaged foods, condiments, and dressings for hidden sources of high omega-6 oils like soybean and corn oil.
Swap Your Cooking Oil: Replace oils high in omega-6s with healthier alternatives. Extra virgin olive oil is ideal for low to medium-heat cooking, while avocado oil is a good choice for high-heat applications due to its higher smoke point.
Balance with Whole Foods: Incorporate omega-3-rich whole foods like fatty fish (salmon, mackerel), flaxseeds, and walnuts into your diet to rebalance the fatty acid ratio.
Choose Cold-Pressed: Whenever possible, choose cold-pressed versions of oils to ensure a higher retention of nutrients and antioxidants.
Avoid Overheating: No matter what oil you use, be mindful of its smoke point. Cooking oil past its smoke point can create harmful free radicals.

Conclusion

Identifying what oils are not anti-inflammatory is a crucial step toward managing chronic inflammation through diet. By understanding the omega-6 and omega-3 imbalance promoted by refined vegetable and seed oils like corn and soybean oil, consumers can make more informed choices. Shifting away from these oils towards options rich in monounsaturated fats, such as extra virgin olive oil and avocado oil, can help rebalance fatty acid intake and reduce inflammatory markers in the body. Remember that moderation and quality are key to using fats as a tool for better health. For more information on dietary fats and inflammation, consult authoritative sources on nutritional science, such as the Cleveland Clinic Health Essentials blog.

Note: While some omega-6 fats are essential, the high consumption found in many modern diets is the primary issue. The goal is balance, not complete elimination.

Frequently Asked Questions

Not all vegetable oils are bad, but many common ones like corn, soybean, and sunflower oil have high omega-6 content. The key is balance; focus on a higher intake of omega-3s and monounsaturated fats from healthier sources like olive or avocado oil.

Canola oil contains a mix of fatty acids, including some omega-3s. However, highly refined canola oil may have its beneficial properties reduced and potentially contribute to inflammation, though less so than oils with a much higher omega-6 profile.

The research on coconut oil and inflammation is mixed and ongoing. While it is a saturated fat, which some studies link to inflammation, a meta-analysis found no significant effect on markers like C-reactive protein. It is best consumed in moderation.

A healthy omega-6 to omega-3 ratio is considered to be between 1:1 and 4:1. The typical Western diet often has a much higher ratio (around 15:1 or more), largely contributing to chronic inflammation.

Highly processed oils use heat and chemicals during extraction, which can remove antioxidants and alter the fats. This makes them more susceptible to oxidation when cooked, creating free radicals that damage cells and promote inflammation.

Both are excellent choices. Extra virgin olive oil is great for low to medium-heat cooking and dressings. Avocado oil has a very high smoke point, making it ideal for high-heat cooking like frying and searing.

No, you should not eliminate all omega-6s. They are essential fatty acids necessary for normal growth and development. The goal is to achieve a healthier balance by reducing high intake from processed foods and increasing omega-3s.