Omega 3 fatty acids in fish oil are believed to protect against heart disease - so much so that the American Heart Association recommends eating at least two servings of fatty fish rich in omega 3 fats every week.

In a new study, scientists from Michigan Technological University now show that fish oil may also protect the heart against the negative effects of acute mental stress. In their study, volunteers who took fish oil supplements for several weeks had a reduced response to acute mental stress when tested for heart health, compared to volunteers who took olive oil instead.

Study authors worked with 67 adult volunteers. At the beginning, each volunteer underwent multiple tests to assess their heart function - including heart rate, blood pressure, muscle sympathetic nerve activity (MSNA) and blood flow through the forearm and calf.


These tests were carried out first when the volunteers were at rest, and then again while they were performing a mental arithmetic test while the investigator encouraged them to hurry - to specifically induce acute mental stress.


The study subjects were then assigned to take either 9 grams of fish oil or 9 grams of olive oil daily. None of them knew which supplement they were taking. Eight weeks later, they underwent the same tests again.


While test results were similar between the two groups at the start of the study, volunteers who took fish oil for eight weeks had remarkably different test results when under mental stress compared to those who took olive oil.


Those in the fish oil group showed reduced heart rate reactivity under stress compared to those who took olive oil. Similarly, the total MSNA reactivity to mental stress was also blunted in the fish oil group.


These results show that fish oil can protect heart function during mental stress. Future studies need to look at the effects of consuming fish oil for longer time periods, for example on older populations or people with heart disease.





Fish Oil Lowers Stress Response