Understanding What Type of Fat Increases Inflammation in the Body

October 11, 2025 •

4 min read

A recent preclinical study demonstrated how even a few meals high in saturated fats can trigger gut inflammation. This highlights why understanding what type of fat increases inflammation in the body is crucial for anyone seeking to manage their long-term health and prevent chronic inflammatory diseases.

Quick Summary

Saturated fats and artificial trans fats are the primary dietary culprits behind increased bodily inflammation. The high intake of omega-6 fatty acids in many Western diets also contributes to a pro-inflammatory state, especially when the balance with omega-3s is poor.

Key Points

Saturated Fats are Pro-Inflammatory: Found in red meat and dairy, these fats trigger an immune response via TLR4 receptors on immune cells.
Artificial Trans Fats Drive Systemic Inflammation: Created through hydrogenation, these fats significantly raise bad cholesterol and contribute to widespread inflammation, increasing disease risk.
Omega-6 to Omega-3 Ratio is Critical: A high ratio of omega-6 to omega-3 fatty acids, common in Western diets, promotes inflammation, while a balanced ratio helps resolve it.
Healthy Fats Fight Inflammation: Monounsaturated fats (olive oil) and omega-3s (fatty fish, flaxseed) are known to have anti-inflammatory properties.
Dietary Shifts Yield Results: Replacing inflammatory fats with healthier alternatives and embracing a whole-foods diet rich in antioxidants is an effective strategy for reducing chronic inflammation.

Chronic inflammation is a significant risk factor for many diseases, including heart disease, diabetes, and certain cancers. While inflammation is a natural and necessary bodily response, persistent, low-grade inflammation can damage tissues and contribute to disease progression. The types of fats we consume play a major role in this process, either promoting or reducing inflammation.

The Inflammatory Role of Saturated Fats

Saturated fats, primarily found in animal products like red meat, butter, cheese, and whole-fat dairy, have long been associated with adverse health outcomes. Research has provided clear mechanistic insight into their inflammatory effects.

How Saturated Fats Trigger an Immune Response

Studies show that saturated fatty acids, particularly palmitic acid, can activate a specific receptor on the surface of immune cells called Toll-like receptor 4 (TLR4). Normally, TLR4 is involved in recognizing and responding to invading pathogens. However, when stimulated by saturated fats, it triggers an inflammatory cascade. This activation leads to the release of pro-inflammatory cytokines—powerful signaling molecules that initiate and sustain inflammation. In fat tissue, or adipocytes, this process contributes to low-grade systemic inflammation, which is a hallmark of obesity.

The Systemic Damage Caused by Trans Fats

Artificial trans fats, or trans fatty acids, are formed during the hydrogenation of vegetable oils, a process that makes them more solid and increases their shelf life. Once common in fried and processed foods, baked goods, and some margarines, trans fats are now widely banned in many countries due to their serious health risks. Their inflammatory effects are particularly potent.

The Mechanisms of Trans Fat Inflammation

LDL and HDL Cholesterol: Trans fats raise harmful low-density lipoprotein (LDL) cholesterol while lowering beneficial high-density lipoprotein (HDL) cholesterol, creating a perfect storm for cardiovascular issues.
Systemic Inflammation: They are known to trigger systemic inflammation, which is strongly linked to heart disease, stroke, diabetes, and other chronic conditions.
Endothelial Dysfunction: By causing inflammation and constriction in blood vessels, trans fats damage the lining of arteries, accelerating the formation of plaque and increasing cardiovascular risk.

Balancing Omega-6 and Omega-3 Fatty Acids

Polyunsaturated fatty acids (PUFAs) include both omega-6 and omega-3 fats. While both are essential, their balance is critical. The typical Western diet often contains a disproportionately high amount of omega-6 fatty acids compared to omega-3s, creating a pro-inflammatory environment.

The Pro-inflammatory Pathway of Omega-6

Omega-6 fatty acids, found in vegetable oils like corn, sunflower, and soybean oil, are precursors to arachidonic acid (ARA). ARA is then converted into eicosanoids, some of which are highly pro-inflammatory, including certain prostaglandins and leukotrienes. The overconsumption of omega-6s, therefore, increases the body's pool of pro-inflammatory signaling molecules.

The Anti-inflammatory Power of Omega-3

Conversely, omega-3 fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found in fatty fish, produce anti-inflammatory compounds called resolvins. Increasing the intake of omega-3s can help counterbalance the inflammatory effects of a high omega-6 diet, shifting the body's inflammatory response towards resolution.

Comparison of Pro-Inflammatory vs. Anti-Inflammatory Fats


Feature	Pro-Inflammatory Fats	Anti-Inflammatory Fats
Primary Types	Saturated Fats, Artificial Trans Fats, Excessive Omega-6	Omega-3s, Monounsaturated Fats, Balanced Omega-6
Dietary Sources	Red meat, butter, full-fat dairy, fried foods, baked goods, vegetable oils (corn, soy)	Fatty fish (salmon, mackerel), flaxseed, chia seeds, walnuts, olive oil, avocados, nuts
Chemical Structure	No double bonds (Saturated), Trans double bonds (Trans)	Cis double bonds (Unsaturated)
Impact on Inflammation	Directly activates immune cells and creates systemic inflammation.	Actively suppresses inflammatory cytokines and produces pro-resolving mediators.
Health Effects	Increased risk of heart disease, type 2 diabetes, stroke, and chronic conditions.	Reduced risk of chronic inflammatory diseases and improved cardiovascular health.

Shifting Your Diet to Fight Inflammation

Changing your dietary fat intake is one of the most effective ways to combat chronic inflammation. Focus on a whole-foods approach, emphasizing nutrient-dense options.

Prioritize Healthy Unsaturated Fats: Incorporate sources of monounsaturated fats, such as olive oil and avocados, and omega-3s from fatty fish, walnuts, and flaxseeds.
Limit Saturated Fat Intake: Reduce consumption of high-fat red and processed meats, fried foods, and full-fat dairy products.
Eliminate Artificial Trans Fats: Avoid foods containing “partially hydrogenated oils” in the ingredients list, as these often contain trans fats.
Increase Fruits and Vegetables: These are packed with antioxidants and fiber that help fight inflammation and support overall health.
Embrace Herbs and Spices: Certain spices like turmeric and ginger have notable anti-inflammatory properties.

For more detailed guidance on adopting an anti-inflammatory eating pattern, the Mediterranean diet is often recommended and aligns well with these principles.

Conclusion

The types of fat you consume significantly influence your body's inflammatory state. By reducing your intake of saturated and trans fats and focusing on a balanced ratio of omega-6 to omega-3 fatty acids, you can actively reduce chronic inflammation. Making conscious dietary choices to favor healthy, anti-inflammatory fats, along with a diet rich in fruits, vegetables, and whole grains, is a powerful strategy for improving overall health and mitigating the risk of many chronic diseases.

Practical Steps to Reduce Inflammatory Fats

Swap vegetable oils like corn and soybean oil for extra virgin olive oil when cooking.
Choose lean protein sources such as fish and poultry over red and processed meats.
Read ingredient labels carefully to avoid partially hydrogenated oils and trans fats.
Snack on nuts and seeds like walnuts and flaxseeds to increase your omega-3 intake.
Incorporate fatty fish like salmon or mackerel into your meals at least twice a week.

Frequently Asked Questions

Saturated fats activate a protein on immune cells called Toll-like receptor 4 (TLR4), triggering an inflammatory response by releasing pro-inflammatory molecules, also known as cytokines.

Primary sources of pro-inflammatory fats include fatty red and processed meats, butter, full-fat dairy products, fried foods, and baked goods containing partially hydrogenated oils.

While both are pro-inflammatory, artificial trans fats have a particularly potent effect, raising bad cholesterol and triggering systemic inflammation linked to heart disease. Saturated fats also promote inflammation, especially in fat tissue.

No, omega-6 fatty acids are essential, but the key is the ratio to omega-3s. High consumption of omega-6s, common in Western diets, can lead to an inflammatory imbalance, but research suggests moderation is more important than elimination.

To get more anti-inflammatory fats, increase your intake of monounsaturated fats from sources like olive oil and avocado, and omega-3s from fatty fish, nuts, and seeds.

Yes, obesity is associated with elevated levels of inflammatory markers. Losing weight, especially by reducing excess fat tissue, can significantly help decrease low-grade systemic inflammation.

Yes, many anti-inflammatory diets, like the Mediterranean diet, can be beneficial for managing arthritis symptoms. They focus on foods that reduce body-wide inflammation, such as oily fish, fruits, and vegetables.