In 1978, Dyerberg and colleagues introduced the novel concept that ω-3 fatty acids in fish may protect against atherosclerosis. Since then there has been fascination with the prospect that ω-3 fatty acids may prevent cardiovascular disease, and in the United States, fish oil supplements are a $1.2 billion–per–year business. The American Heart Association recommends that adults eat fish at least twice weekly, and that patients with coronary disease ingest 1 g per day of eicosapentanoic acid and docosahexanoic acid, the 2 principal ω-3 fatty acids found in fish.
Curfman G. The Unfulfilled Promise of ω-3 Fatty Acid Supplementation. JAMA Intern Med. Published online January 03, 2017. doi:10.1001/jamainternmed.2016.8236