Fish Oil and Supplements of EPA/DHA – Reducing the Stress Response

Essential fatty acids (EFAs) are a crucial aspect of adaptation. However, they are not produced in the body, so dietary sources or supplements are often needed to obtain these critical nutrients. EFAs are incorporated into cell membranes throughout the body, especially in the brain and nervous system – they are needed for the transport of nutrients, chemical messengers, hormones, and neurotransmitters into cells, leading to normal cell function. The integrity of the cell membrane and organelles inside the cell is dependent on normal levels of fatty acids.  

Essential fatty acids are important in energy production, oxygen transport, cell-to-cell communication, and the myelination of neurons in the central nervous system. They are the building blocks of the eicosanoid hormones and the prostaglandins, which are key regulators of inflammation in the body. Any change in the dietary intake of fats has a profound effect on cell membranes, cell function, inflammation, and levels of cortisol – it’s no wonder that so many studies have confirmed the importance of eating the right fats to maintain health. 


How omega-3 fatty acids affect stress

Researchers in France (Delarue et al. 2003) did one of the most important studies regarding the connection between omega-3 fatty acids and stress. They measured the stress response to mental arithmetic and other stressors before and after feeding human volunteers 7.2 grams of fish oil a day as supplements for three weeks. The measurements included plasma cortisol, catecholamine (epinephrine and norepinephrine), and non-esterified fatty acid. The response to stress, including elevations of cortisol, epinephrine, and fats, was dramatically reduced by supplementation with omega-3 fatty acids. They concluded that adrenal activation could be inhibited by adequate intake of omega-3 fatty acids. The site of action is in the central nervous system. Furthermore, it was postulated that essential fatty acid supplementation might reduce the injury to the hippocampus from cortisol and slow the subsequent development of Alzheimer’s disease and other manifestations of premature aging.


Managing cortisol with EPA/DHA supplementation

Low dietary intake of omega-3 fats from fish has been associated with increased anger, aggression, and depression in some people – taking EPA/DHA supplements (EPA and DHA are the two key fatty acids in fish) can reduce these effects. A study done at the New York Veterans Administration hospital by Buydens-Branchey and colleagues (2000) found that in male outpatients who had aggressive behavior and substance abuse, a daily 3-gram dose of fish-oil supplements (containing 2,250 milligrams of EPA and 500 milligrams of DHA) reduced anger scores significantly, compared to a placebo. Because anger and aggression equate to high cortisol levels, this study confirms the benefits of omega-3 supplementation in reducing cortisol elevation.

Researchers in Japan (Hamazaki and Itomura 2000) showed a decreased norepinephrine concentration (31 percent less) in students given 1.5 grams of DHA during the week of an exam. They also showed a marked reduction in measures of hostility (72 percent less) in students on EPA supplementation compared to controls, when faced with the stress from final exams. (Norepinephrine, the acute stress hormone of the autonomic nervous system and the midbrain, will eventually lead to higher cortisol levels when chronically elevated.)

In 2010, Noreen and colleagues showed that EPA/DHA can blunt the increase in cortisol found after intense exercise. They studied forty-four men and women, who were put on either 4 grams of EPA/DHA (providing 1,660 milligrams of EPA and 800 milligrams of DHA) or 4 grams of safflower oil. After six weeks of treatment, there was a significant decrease in cortisol and fat mass, and an increase in fat-free mass in the group on EPA/DHA. This study showed the benefit of lowering cortisol in terms of reducing fat mass and losing weight. The proposed mechanism of lowering cortisol is through reduction of the inflammatory cytokine IL-6, which can stimulate the hypothalamic-pituitary-adrenal axis independent of CRH. Controlling inflammation is a critical goal in managing weight and reducing excess cortisol.


Connections between stress and healthy fats

All these studies have the same conclusion: if enough of the right fats are eaten, the brain will not respond excessively to stress.  The fats in the diet matter in terms of brain health and adaptation because they are incorporated right into the brain itself. This was also the opinion of other researchers, including Lanfranco and colleagues (2004), who found that essential fatty acid administration inhibits cortisol production through a mechanism in the brain itself, not in the pituitary or the adrenal glands. In mice that have brain lesions similar to those of Alzheimer’s disease, use of essential fatty acids reduced damage to the hippocampus during stress and prevented the development of additional Alzheimer’s-like brain lesions.

Another major connection between EPA/DHA and reduction of cortisol is the impact these fatty acids have on inflammation. As I discussed earlier, EPA and DHA are building blocks for the anti-inflammatory eicosanoid hormones. The use of foods rich in EPA/DHA tips the balance of eicosanoid hormones toward the anti-inflammatory cytokines helping to resolve inflammation. In addition, recent findings by Calder (March 2012) reveal another target of these valuable fats. Substances called pro-resolution molecules, including lipoxins, resolvins, and protectins are used by the body to turn off chronic inflammation. EPA/DHA has a major influence on enhancing production of these molecules, reducing chronic inflammation and therefore cortisol levels.


Next-steps: How YOU can control your cortisol levels

A major step in controlling cortisol is including the right fats in your diet: omega-3 fats from cold-water fish (wild salmon, sardines, herring, low-mercury tuna), as well as vegetable sources (flaxseeds, walnuts, pumpkin seeds, and dark green leafy vegetables). Monounsaturated fats from almonds, avocados, olive oil, grapeseed oil, and canola oil should be the main fats in the diet. In addition, strictly avoid trans fats.  Also reduce the use of polyunsaturated omega-6 fats found in corn oil, safflower oil, soybean oil, and other partially hydrogenated oils. Reducing the intake of saturated fats from beef, whole dairy products, and egg yolks also decreases the inflammatory response. 

In addition, it is helpful to control cortisol levels by supplementing with EPA/DHA capsules on days when fish is not consumed. A reasonable dose for cortisol balance and adaptation is 1,000-1,200 milligrams of EPA, and at least half as much DHA. Most supplements have between 160 and 320 milligrams of EPA per capsule. If you have any bleeding problems or use anticoagulants, fish-oil use needs to be supervised by a physician. Some people cannot tolerate fish oils without digestive upset. To prevent oxidative stress from high-dose fish-oil supplements, it is important to use a good antioxidant supplement.