What Causes Inflammation?

Trans Fat, Saturated Fat and Inflammation

Studies have shown that diets high in trans fatty acids and saturated fatty acids can have pro-inflammatory effects. Trans fatty acids, in particular, have been shown to increase CRP, IL-6, and TNFa. It is important to note, however, that neither of these fats had a very strong inflammatory effect when consumed in a low to moderate fat diet. This suggests that it is the level of fat in an individual’s diet which influences the pro and anti-inflammatory effects of trans and saturated fatty acids, causing them to be more inflammatory than normal when consumed in high amounts.

Foods which are high in trans fatty acids are cooked with hydrogenated or partially-hydrogenated oil. These include many processed foods, such as cookies, crackers, and chips. The safest way to identify foods which contain trans fats is to look at the ingredient list. If you see the word “hydrogenated”, the food contains at least some trans fat. Due to labeling law, a food is allowed to advertise itself as “Trans Fat Free” if it contains less than .5 grams per serving, so the only way to be sure something is really trans fat free is to look at the ingredient list. Trans fat should be completely avoided for health reasons which do not deal directly with inflammation.

Foods which are high in saturated fatty acids are primarily animal products, mostly grain-fed animals. Grain-fed meat is also higher in a few other pro-inflammatory compounds, and lower in anti-inflammatory ones, so if reducing inflammation is a goal, look for grass-fed or pastured meat.

Certain plant oils, such as coconut and palm oil, are also high in saturated fatty acids, but it is important to note that both unrefined coconut and palm oils also have strong anti-inflammatory compounds as well.

Also remember that the strongest link to inflammation through saturated fats is the total amount of fat consumed in a day. Saturated fat, by itself, is not necessarily pro-inflammatory, and when consumed in whole, unprocessed food, is likely packaged with a number of anti-inflammatory compounds as well.

Omega-6 Fatty Acids: The Balancing Act

Omega-6 fatty acids can be pro-inflammatory, but as with saturated fatty acids, it comes with an addendum. When omega-6 consumption greatly exceeds omega-3 consumption, then our body becomes overloaded with arachidonic acid, the fat our body creates from omega-6 fatty acids. Both omega-6 and omega-3 fatty acids are essential–our body cannot produce them itself, so we must consume them in our diet. Both omega-6 and omega-3 are integral parts of our cell membranes as well, and they are found in our cell membranes in proportion to the amounts of them we eat. This means that, when speaking of inflammation, the most important thing to keep in mind is the ratio of omega-3 to omega-6, not just the total amount.

While we can consume arachidonic acid directly when we eat meat, far and away the most common source of omega-6 fatty acids, and thus of arachidonic acid, is certain types of plant oils. Sunflower, safflower, soybean, corn, and cottonseed oil contain the most omega-6s, and with the exception of soy are virtually devoid of omega-3s (even soybean oil is too low to consider it a good omega-3 source). You may have noticed that these five oils happen to be the most frequently used oils in processed food–that is no mistake. Omega-6 fatty acids are not prone to rancidity like omega-3s are, and thus are used for processed food products so they won’t go bad on the shelf.

The World Health Organization suggests that we should aim for our omega-3:6 ratio to be at least 1:5 to 1:10, but optimal health lies in the 1:1 to 1:4 range. The average American diet provides a ratio of roughly 1:11 to 1:20, more commonly at the upper end, which means that for every one gram of omega-3s we consume, we consume eleven to twenty grams of omega-6s.

Simply consuming more omega-3 fatty acids is not a viable solution for most people since we tend to consume so many omega-6s through processed food. A single serving of chips contains, on average, 2.5-3 grams of omega-6 fatty acids. The average can of tuna, on the other hand, contains only about .5 grams of omega-3s. Fresh fish contains more omega-3 (an equivalent amount of fresh tuna has 2.5 grams), but it would be hard to eat a serving a fish for every handful of potato chips we eat.

The best solution to reduce the pro-inflammatory effects of a diet high in omega-6 fatty acids is to eat less of them, primarily by reducing processed food consumption.