Doctors in one study said the body releases the hormone cortisol to respond to stress, but when cortisol levels remain high, the body can become unhealthy. Researchers asked 44 healthy men and women, average age 34, to maintain their diet and exercise routines while taking 1,600 mg of EPA (eicosapentaenoic acid) plus 800 mg of DHA (docosahexaenoic acid) per day, or a placebo. After six weeks, compared to placebo, the omega-3 group had much lower levels of cortisol, much less fat mass and more lean muscle mass.