The common advice for people who have been diagnosed with heart problems like hypertension is "eat more fish, especially salmon." I've done a great deal of Googling and what I can't seem to figure out is whether fish is actually good for hypertension, or if it's just better than eating an equivalent portion of red meat or pork.
Question: Does eating (fatty) fish help to lower high blood pressure or does it help only when eaten instead of red meat?
Answer: Merely increasing fish, including oily fish, consumption without other dietary changes (especially losing excessive weight) may not help to reduce blood pressure.
In our study, fish consumption was associated with a slight increase in hypertension risk.
Consumption of fatty fish resulted in significant improvements in triglycerides and HDL cholesterol, whereas no effects were observed for...systolic and diastolic blood pressure.
According to one systematic review (American Society of Nutrition, 2017), consumption of red meat is associated with high blood pressure, but in some other studies (ResearchGate, 2014; Nutrition Journal, 2017) no such association have been found.
THE DIET AS A WHOLE
There is strong and consistent evidence that consumption of a DASH [Dietary Approaches to Stop Hypertension] diet results in reduced blood pressure in adults with above optimal blood pressure... A dietary pattern consistent with the DASH diet is rich in fruits, vegetables, low-fat dairy, fish, whole grains, fiber, potassium, and other minerals at recommended levels, and low in red and processed meat, sugar-sweetened foods and drinks, saturated fat, cholesterol, and sodium.
According to the American Heart Association should have fish high in omega 3 fatty acid twice a week.
The American Heart Association recommends eating fish (particularly fatty fish) at least two times (two servings) a week. Each serving is 3.5 ounce cooked, or about ¾ cup of flaked fish. Fatty fish like salmon, mackerel, herring, lake trout, sardines and albacore tuna are high in omega-3 fatty acids.
Increasing omega-3 fatty acid consumption through foods is preferable. However, those with coronary artery disease, may not get enough omega-3 by diet alone. These people may want to talk to their doctor about supplements. And for those with high triglycerides, even larger doses could help.
Omega-3 fatty acids also decrease triglyceride levels, slow growth rate of atherosclerotic plaque, and lower blood pressure (slightly).