There have been several studies which have shown that diets high in
omega-3's or even fish-oil supplements, can lower high blood pressure. You don't want to self-medicate, however. High Blood Pressure is a serious condition. Make sure you get your doctor's approval before you do anything.
It's been shown time and time again that diets low in saturated fats and high in monounsaturated and polyunsaturated fats (this includes
omega-3 efas) help prevent heart disease. There is a lot of clinial evidence that fish-oil, which is high in EPA and DHA (two types of
omega-3 essential fatty acids) help reduce instances of heart problems and cardiac event. In addition, fish oil has been shown to have a very good positive effect on lowering triglycerides, risk of death from heart disease, stroke, and abnormal heart rhythms. Fish-oil has also been proven to help mitigate and treat hardening of the arteries through slowing the development of plaque and blood clots.
In other words, fish oil, which contains considerable amounts of EPA and DHA, is really healthy for you. Since with DHA you get a double whammy effect of helping your heart and brain, you probably want to consider DHA supplements in what you eat. As in all things medical, talk to your doctor first.