Inflammation is a normal biological response against foreign or harmful pathogens and plays an instrumental part in healing. However, chronic inflammation can occur when there are no pathogens present. Its persistence in the body over many years can contribute to the development of multiple health disorders. Previous studies show that around 34.6% of adults in the U.S. have systemic inflammation.

Research on chronic inflammation is important to understand how it develops and the factors that may contribute to its manifestation in the body. In a study published in the Open Access journal Nutrients, researchers from the U.S. set out to learn whether the key nutrient omega-6 increases or decreases inflammation.

What is omega-6?

Omega-6 fats are naturally occurring polyunsaturated fatty acids. This means that, unlike saturated fatty acids, they are essential for health and are commonly referred to as healthy fats. They cannot be produced by the body, but play a vital role in many bodily functions, such as energy storage and cell membrane integrity. Omega-6 is obtained from food as part of a balanced diet. It is present in foods such as vegetable oils, pine nuts, walnuts, sunflower and pumpkin seeds.

Omega-6 also plays a role in mediating inflammatory responses in the body, with some research suggesting it promotes inflammation, while other research suggests it reduces inflammation. These opposing findings have led to some controversy, with many feeling confused about the benefits or risks of consuming omega-6.

Unlike its more well-understood counterpart, omega-3, which is known to be highly beneficial for health and an integral component of the Mediterranean diet, omega-6 is surrounded with a little more confusion. The researchers behind the study in Nutrients sought to demystify its role in inflammation by carrying out a study to observe the inflammatory markers associated with two different types of omega-6 fatty acids.

Markers of inflammation

There are several types of omega-6, including linoleic acid (LA) and arachidonic acid (AA). Researchers of the study analysed the link between specific inflammatory markers and these specific fatty acids present in the cell membranes of red blood cells (RBC). The analysed inflammatory markers included the following:

• C-reactive protein
• Interleukin-6
• Intracellular adhesion molecule-1
• Monocyte chemoattractant protein-1
• P-selectin
• Oesoeoprotegrin
• Lipoprotein-associated phospholipase-A2
• Urinary 8-epi-PGF2α isoprostanes
• Tumour necrosis factor receptor-2

Each of the markers plays well-established roles in mediating key inflammatory processes. The detection and presence of these biomarkers are signatures of pro- and anti-inflammatory mechanisms. Therefore, analysing the link between these factors and RBC LA and AA can demonstrate whether omega-6 is associated with inflammation.

Research findings

The researchers analysed the serum and plasma of 2777 participants. The study was a cross-sectional study, which meant that both the inflammatory markers and fatty acids were measured in the same samples and then statistically analysed.

“These new data show clearly that people who have the highest levels of LA (and AA) in their blood are in a less inflammatory state than people with lower levels. This finding is exactly the opposite of what one would expect if omega-6 fatty acids were ‘proinflammatory’ – in fact, they appear to be anti-inflammatory,” explained study investigator William S. Harris, Professor at Sanford School of Medicine, University of South Dakota, Sioux Falls, SD.

After adjusting for factors that may have impacted the results, such as age, race, sex, smoking habits, blood lipid levels, blood pressure, and body weight, the researchers found a small but statistically significant inverse correlation between omega-6 fatty acids and six essential inflammatory markers. Therefore, the results suggest that omega-6 is more likely to be associated with anti-inflammatory pathways rather than pro-inflammatory pathways.

“In the flurry of news stories about the harms of seed oils – the primary sources of LA in the diet – many voices are calling for reducing Americans’ intakes of LA. This is not a science-based recommendation, and this study – in addition to many more – point in precisely the opposite direction: instead of lowering LA intakes, raising intakes appears to be a healthier recommendation,” Dr. Harris continued. “These findings contradict a narrative, not previous research findings. There are many studies in the medical literature that are consistent with our findings here.”

Understanding the biology behind omega-6 and other key macro- and micronutrients is essential in understanding how diet impacts our bodies. In particular, it is critical in evaluating the role of specific components in the development of disease.

These new findings regarding the link between omega-6 and inflammation is important in elucidating omega-6’s role in inflammation, helping to reduce potential confusion surrounding the role that key nutrients play in keeping healthy.

Read more about research like this by accessing the journal Nutrients, or click here for the full journal list.