Published: May 1, 2010 Authors: Rebecca Wall, R Paul Ross, Gerald F Fitzgerald, Catherine Stanton
- A typical Western diet has too many omega-6 fats. This can increase inflammation and contribute to chronic diseases
- Omega-3 fats found in fish like salmon can help reduce inflammation and support a healthy immune system
- Eating more oily fish or taking fish oil supplements could help reduce the risk of health problems linked to inflammation
Omega-6 and omega-3 are special kinds of fats that our bodies need.
These fats help make tiny messengers called eicosanoids, which help control how our body deals with swelling and inflammation.
Eicosanoids made from omega-6 fats can cause more swelling, while those made from omega-3 fats can help reduce swelling.
In a typical Western diet, people eat more omega-6 fats than omega-3 fats. This can lead to more swelling in our bodies. This can be especially problematic for people with autoimmune disorders with an inflammatory component, such as ankylosing spondylitis.
It makes swelling worse and increases the chances of getting diseases linked to inflammation. By eating more good fats like omega-3 fats found in fish, we can lower the risk of many health problems like arthritis, diabetes, obesity, cancer, heart disease, and even help with our mental health.
The study suggests that by doing this we can lower the chances of a) getting certain diseases in the first place and b) help those already dealing with inflammatory issues fight swelling and improve their immune systems, making it more anti-inflammatory.
Technical details from the study
“Inappropriate, excessive or uncontrolled inflammation contributes to a range of human diseases. Inflammation involves a multitude of cell types, chemical mediators and interactions. The present article will describe nutritional and metabolic aspects of omega-6 (n-6) and omega-3 (n-3) fatty acids and explain the roles of bioactive members of those fatty acid families in inflammatory processes.”
“PUFAs have a role in regulating inflammatory responses through the production of inflammatory mediators termed eicosanoids.
The human body can produce all but two of the fatty acids it requires. Thus, linoleic acid (LA, C18:2n-6) (precursor of the n-6 series of fatty acids) and α-linolenic acid (ALA, C18:3n-3) (precursor of the n-3 series of fatty acids) are essential in the human diet; a dietary (n-6):(n-3) ratio of 4:1 is recommended as optimal.
However, actual dietary intakes of these fatty acids are in excess of 15–16:1, particularly in Western countries, due to increased consumption of LA-rich vegetable oils.3 As an example, in Europe, consumption of LA has increased by 50% during the last two decades.
In parallel with increased LA intakes, increased rates of many diseases that involve inflammatory processes have occurred, most notably cardiovascular diseases, inflammatory diseases, obesity, cancer, and certain psychiatric diseases such as depression.
This increasing inflammatory disease incidence is associated with excessive production of the proinflammatory eicosanoids, prostaglandin E2 (PGE2) and leukotriene B4 (LTB4), which are derived from the n-6 fatty acid arachidonic acid (C20:4n-6) that is maintained at high cellular concentrations by the high n-6 and low n-3 PUFA content of the modern Western diet.
However, this imbalance can be corrected by dietary supplementation with n-3 fatty acids such as EPA (C20:5n-3) and DHA (C22:6n-3) or by eating fish rich in EPA and DHA. EPA and DHA in the diet partially replace arachidonic acid as an eicosanoid substrate in cell membranes; this probably occurs in all cells, but it is especially true in the membranes of erythrocytes, neutrophils, monocytes, and liver cells and thus suppresses the production of n-6 proinflammatory eicosanoids.
Marine fish are the principal sources of EPA and DHA.8 However, the content of marine n-3 fatty acids varies greatly according to the species of fish. For example, fish such as salmon, trout, and herring are higher in EPA and DHA than others (e.g., cod, haddock, and catfish).
It is acknowledged that EPA and DHA can prevent the development of inflammatory diseases by directly or indirectly affecting different stages of the immune response. In addition, EPA and DHA can alleviate inflammatory processes that already exist, thus highlighting the therapeutic importance of these fatty acids.”
“Increased consumption of fatty fish or fish oil supplements containing n-3 PUFAs increases the amount of these fatty acids and their metabolites in human immune cells and consequently changes the production of important mediators and regulators of inflammation and immune responses towards an anti-inflammatory profile.
Since excessive intake of n-6 PUFAs, which is characteristic of Western diets, could potentiate inflammatory processes and consequently predispose to, or exacerbate, inflammatory diseases, increasing intake of fatty acids that elicit anti-inflammatory effects, such as n-3 PUFAs, could decrease the risk of many chronic diseases like arthritis, diabetes, obesity, inflammation, cancer, and cardiovascular disease as well as improve mental health.
Based on the recognized health effects of n-3 PUFAs, recommendations have been made to increase dietary intake of these fatty acids; this can be achieved by increasing consumption of oily fish or by consuming fish oil supplements.”