Long before the health movement became popular, fish oil was recognized as a healthy part of a nutritious diet. The actual benefit didn't really become known until the 1970s when ingestion of these oils apparently led to better cardiovascular health. Within a few decades, the oil (as well as the fish itself) was suggested as a means to keep heart disease at bay. Today, we know of several chemicals contained within the oil that improve our health. Some of the best are the omega-3 fatty acids.