Kyle, quick answer: neither.
Longer answer:
"There is no doubt that the omega 3 fatty acids found in fish are valuable but there are other, safer sources of these acids...
......Omega-3 fatty acids - You can fulfill your daily requirement by consuming one tablespoon of flaxseed meal each day - perhaps sprinkling it over cereal. Be sure to refrigerate ground flaxseed." Caldwell B. Esselstyn, Jr. M. D.
For those without heart disease walnuts (in moderation) provide omega 3 fatty acids.
NO REFINED OILS.
Chapter 10 is titled "Why Can't I Have "Heart Healthy" oils.
Olive oil is 14-17% saturated, artery clogging fat.
Studies are cited where heart disease progressed just as much as those consuming monounsaturated fats as it had in those eating saturated fats.
Monounsaturated fats do increase HDL and lower LDL but coronary disease still develops.
It has to do with the fats temporarily injuring the endothelial cells in the lining of the artery compromising their ability to produce nitric oxide. Nitric oxide is what keeps arteries slick and keeps plaque from developing.
For pages and pages of details (to the cellular level) and for the studies:
"Prevent and Reversing Heart Disease" by Caldwell B. Esselstyn, Jr. M. D.