Because the body converts all dietary sources of vitamin A into retinol, 1 mcg of physiologically available retinol is equivalent to the following amounts from dietary sources: 1 mcg of retinol, 12 mcg of beta-carotene, and 24 mcg of alpha-carotene or beta-cryptoxanthin.
The body needs more omega-3 than omega-6 to reduce the risk of heart disease and inflammation. Since olive oil is higher in omega-3 than other oils, sardines in olive oil contain more omega-3 than sardines in water; however, the sardines in water are still the better option with lower amounts of cholesterol and fat.
Like all canned foods, sardines and herrings can be high in sodium, but the amounts vary. A 3-ounce serving of canned sardines in oil has 417 milligrams, or 29 percent of your daily value, compared to pickled herrings with 740 milligrams, which is half your daily intake.ardines and herrings are rich sources of omega-3 fatty acids. Herrings and sardines are so similar that herrings are often canned and labeled as sardines.