For many people who experience mental stress, the body responds by raising heart rate and blood pressure, as well as increasing nerve activity of muscles. This phenomenon is believed to be one way in which stress leads to high blood pressure, which has implications for heart disease development.

These days, most people experience mental stress on a regular basis, which may help to explain why heart disease is still the number one cause of death. A recent study published in the American Journal of Physiology—Regulatory, Integrative, and Comparative Physiology sheds some light on how omega-3 fish oil might help to reduce these negative effects of mental stress.1

The researchers found that supplementation of 1.6 grams EPA and 1.1 grams of DHA daily for eight weeks reduced heart rate and muscle sympathetic nerve activity induced by mental stress in people with normal blood pressure when compared to those taking placebo. “Overall, the data support and extend the growing evidence that fish oil may have positive health benefits regarding neural cardiovascular control in humans and suggest important physiological interactions between fish oil and psychological stress that may contribute to disease etiology,” they stated.

They also expected to see a lowering of blood pressure, but did not. They offered the short duration of the study, younger age, and normal blood pressure of the participants as an explanation for not seeing this effect.

Harry Rice, VP of regulatory and scientific affairs for the Global Organization for EPA and DHA Omega-3s (GOED), commented on the study: “The present research suggests that fish oil intake may blunt the ability of mental stress to create chaos with one’s physical health. To the extent that the results can be extrapolated further downstream, this could mean the attenuation of disease initiation or progression.”

This study builds on previous evidence for fish oil’s protective effect against mental stress. Fish oil has also been found to inhibit adrenal activation induced by mental stress in a study published in Diabetes Metabolism in 2003.2 The adrenals secrete a variety of chemicals in response to stress. This study found that fish oil reduced the secretion of adrenaline (epinephrine) and cortisol (the stress hormone) in response to mental stress.

Since we all experience mental stress on a regular basis, fish oil offers a great way to help curb its harmful effects. This is one of many benefits of omega-3 EPA and DHA fatty acids. By addressing the precursors to chronic disease, such as the negative effects of stress, we can help to avoid later progression to chronic poor health.



  1. Carter JR, Schwartz CE, Yang H, et al., “Fish oil and neurovascular reactivity to mental stress in humans.” Am J Physiol Regul Integr Comp Physiol. 2013 Apr 1;304(7):R523-30.
  2. Delarue J, Matzinger O, Binnert C, et al., “Fish oil prevents the adrenal activation elicited by mental stress in healthy men.” Diabetes Metab. 2003 Jun;29(3):289-95.