Acute inflammation is a normal process involving a healthy immune response (redness, pain, swelling) with the purpose of healing and repairing the injured area. There is a dark side of inflammation when this process does not stop, however. Repeated or prolonged infections, gum disease, smoking or obesity can trigger this process. In these conditions, cells churn out chemicals called cytokines. Inflammation over time has been linked to the development of chronic diseases such as heart disease, Alzheimer’s, cancer, diabetes and stroke among others.
No reliable test can detect chronic inflammation in the body. What is known is that people with poor health habits tend to have higher levels of inflammation and it’s associated with an imbalance of cytokines, i.e. too many pro-inflammatory cytokines and not enough anti-inflammatory ones. Often a diet high in healthy fats can help stem the effects of this imbalance.
The omega-6 and omega-3 fatty acids are metabolically distinct and have opposing physiologic functions. Ideally, the diet should contain about a 4:1 ratio of omega-6 vs. omega-3 fats; however, the American diet ratio has been estimated to be about 15:1.
Omega-6 fatty acids are abundant in the American diet (found in corn oil, safflower oil, soybean oil) and influence the production of pro-inflammatory cytokines.
Omega-3 fatty acids are less abundant in the American diet (found in fish oils). Omega-3 fats are also found in flaxseed oils, but this form does not convert easily to the more beneficial fatty acids, EPA and DHA in fish.
Dietary fatty acids influence the balance of pro-and anti-inflammatory cytokines by producing hormone-like compounds called eicosanoids. They have various roles in inflammation, fever, regulation of blood pressure, blood clotting, immune system modulation, control of reproductive processes and tissue growth, and regulation of the sleep/wake cycle.
There are three major ways that omega-3 fatty acids (EPA and DHA) influence the production of eicosanoids:
- First of all, omega-3 fatty acids produce far less eicosanoids that do the omega-6 fatty acids.
- Second, omega-3 fats compete with omega-6 fats for the starting compound of the pathways that produce eicosanoids.
- Third, the omega-3 eicosanoids, are generally 2 to 50 times less active than those formed from the omega-6 fatty acids.
There have been a number of placebo-controlled clinical trials assessing the benefits of dietary supplementation with fish oils in several inflammatory and autoimmune diseases in humans, including rheumatoid arthritis, Crohn’s disease, ulcerative colitis, psoriasis, lupus erythematosus, multiple sclerosis and migraine headaches. They reveal significant benefits, including decreased disease activity and a lowered use of anti-inflammatory drugs.
A new study assessing the impact of consuming more fish oils showed a significant reduction in inflammation as well as anxiety (surprisingly) among a cohort of healthy young persons.
This study at Ohio State was published in Brain, Behavior and Immunity. It’s been known that stress increases cytokines in the body, so researchers hypothesized that increasing the omega-3 content of the diet might alleviate that process, including inflammation.
Three groups of medical students were given omega-3 supplements compared to three groups given a placebo during an intense 3-day period of test taking. Blood tests were done as well as a battery of psychological surveys to assess stress, anxiety or depression. The students also kept food diaries.
“The supplement was probably about four to five times the amount of fish oil you’d get from a daily serving of salmon”, said Martha Belury, professor of human nutrition and co-author in the study.
The psychological surveys clearly showed an important change in anxiety – those receiving the omega-3 showed a 20% reduction in anxiety compared to the placebo groups. “We saw a 14% reduction in the amounts of interleukin-6, a pro-inflammatory cytokine, among the students receiving the omega-3,” according to the authors.
In a randomized study, 23 hospitalized patients with systemic inflammatory response syndrome or sepsis were given fish oil by injection. Traditionally soybean oil had been given (no omega-3 fatty acids), but rich in omega-6 fatty acids that may actually promote inflammation. 13 patients in the fish oil group had lower levels of inflammatory agents in their blood, were able to achieve better lung function and left the hospital earlier than the 10 patients who received the traditional soybean oil treatment.
This doesn’t mean that we all go out and take huge amounts of fish oil supplements. Of course eating fatty fish a couple of times a week should benefit us over time but taking a fish oil capsule should be discussed with your physician.
- Who Needs Omega-3s? (webmd.com)