I have been eating lots of oysters and sardines to bump up my omega-3 ratio. Am I negating the benefits by eating sardines and oysters that are packed in olive oil (because the olive oil has a high omega-6 ratio)?
I also eat fish (salmon, cod, etc.) about 2-3x per week, but sometimes I get bored of it because I'm a horrible cook. (please, no recipes that take more than 20 minutes and four ingredients).
Also, I stopped taking fish oil pills because over time I think they were causing me heart burn/acid reflux issues (http://paleohacks.com/questions/110294/never-had-heartburn-before-are-the-paleo-gods-mad-at-me#axzz1vhXRbTNI). So I would like to get my o-3s all from diet if possible.
I am focused on omega-3 consumption for depression and preventing/healing injuries from weightlifting.
Maybe. Olive oil n6 content can vary quite a bit. I'm guessing they don't use the good stuff to can with. Olive oil isn't ideal, but it's not as bad as most veg oils. Use a paper towel to drain/wipe off the excess or switch to water packed.
Hey watch out. The Wild Planet Sardines are usually BPA free but the Crown Prince Oysters are not. Those nasty xenoestrogens will screw you up so bad (thyroid, hormones, and cancer risk). I was eating Crown Prince Sardines x2 a day for a few weeks until I discovered it had extremely high amounts of BPA in it. During that time I had my thyroid tested and even though I'm 8% body fat, I was also somehow subclinical hypothyroid - I blame the BPA sardine cans. I called Crown Prince and they said only a select few of their Brisling sardines packed in Ireland are BPA free and that they are having a hard time finding packing companies who can provide BPA free cans. Now I only eat Wild Planet Sardines.
Sardines are an amazing source of omega 3 and very low in mercury. I usually split them 50/50 between olive oil or water packed.
What I love most about Sardines is that they are the perfect long distance car trip food! I bought 30 cans on my trip from North Carolina to Toronto, Canada so I wouldn't screw up and eat crappy highway food.
If you're interested in bumping your omega-3 ratio, you're better off eating fresh fish! If convenience is an issue, I've heard that canned salmon is actually quite good. For whatever reason, farmed salmon doesn't hold up well when canned, so most canned salmon is wild-caught. You can also take fish oil supplements (either liquid or gel tablet).
As you said, olive oil has a high omega-6 content, which can be detrimental because the aim in consuming omega-3 is to balance your omega-3:omega-6 ratio. Also, remember that olive oil has a lot of calories!
Please don't take fish oil supplements - Google "Brian Peskin fish oil". Omega 6 oil is not bad for you if it's raw, organic. and cold pressed. PROCESSED O6 (soybean,safflower,palm,etc) IS bad for you. A friend of mine is the lead researcher at NIH who studies fats and their affect on the brain. The evidence clearly shows that we need very little O3 fats (maybe 1000mg/day) and the best way to improve your O6/O3 ratio is not to increase your O3 but to stop using processed vegetable oils and other processed O6 sources. Rare to medium grass fed steaks will give you what you need. Cold pressed, raw, organic hemp oil gives you the exact O6/O3 ratio as well. Fish gives you mostly DHA and EPA which are DERIVATIVES of omega-3. Your body actually needs the parent form of O3 for many processes and will convert the DHA and EPA from the parent O3 as needed. Please do a Google search on Brian Peskin.
There area lot of environmental problems associated with eating fish (over fishing, by catch, etc) The world's fisheries are expected to collapse by 2050 due to misuse, so if you choose to continue eating it, please research carefully the methods used to fish the seafood you are purchasing.