Fish oil may slightly blunt some responses to mental stress, according to a study of young men and women given a large amount of fish oil (
9 grams daily providing 1,600 mg EPA and 1,100 mg
DHA) for eight weeks. When the participants were asked perform math calculations as quickly as possible for 5 minutes (a mental stress test), the mean heart rate increased by 3 beats less per minute after fish oil therapy than when the test had been taken at the beginning of the study, before therapy.