Fish Oil No Better Than Olive Oil for Reducing Cardiovascular Risk in Diabetics

A major new study on the ben­e­fits of fish oil found that omega‑3 fish oil sup­ple­ments failed to pre­vent first-time heart attacks or strokes in dia­bet­ics. The ASCEND study’s dis­ap­point­ing results were revealed at the European Society of Cardiology’s Annual Congress.

15,500 vol­un­teers with dia­betes (which is believed to dou­ble or even triple the risk of car­dio­vas­cu­lar dis­ease) were recruited for the study. None of the par­tic­i­pants had heart dis­ease at the start of the study which was under­taken to explore if fish oil sup­ple­ments reduced their car­dio­vas­cu­lar risk.

During the study, half of the patients were given a daily 1‑gram cap­sule of n‑3 fatty acids while the other fifty per­cent took a placebo con­tain­ing olive oil. There was no sig­nif­i­cant dif­fer­ence recorded in the rate of heart dis­ease or strokes between par­tic­i­pants who took the fish oil sup­ple­ment and those who con­sumed the olive oil placebo.

Participants were mon­i­tored for an aver­age of seven and a half years. Throughout the study, 9.2 per­cent of peo­ple tak­ing the placebo died of heart dis­ease, suf­fered a non-fatal heart attack or stroke, or expe­ri­enced a mini-stroke known as a tran­sient ischemic attack (TIA). Among fish oil recip­i­ents the rate stood at 8.9 per­cent, a sta­tis­ti­cally insignif­i­cant dif­fer­ence.

It was also found that fish oil sup­ple­ments didn’t sub­stan­tially lower the need for a blocked artery to be reopened any more than the placebo. The pro­ce­dure was car­ried out on 11.5 per­cent of the placebo group and 11.4 per­cent of the fish oil group.

When all causes of death were exam­ined it was found that there was lit­tle dif­fer­ence in the death rates, with 9.7 per­cent of the fish oil group dying dur­ing the study com­pared to 10.2 per­cent of the olive oil placebo group.

Louise Bowman, one of the study’s authors and pro­fes­sor of med­i­cine and clin­i­cal tri­als at the University of Oxford’s Nuffield Department of Population Health told Reuters, ​“The study pro­vides much-needed clar­ity regard­ing the ben­e­fits of fish oil sup­ple­ments for peo­ple with dia­betes but no his­tory of car­dio­vas­cu­lar dis­ease.”

Bowman went on to say, ​“The fish oil sup­ple­ments were safe, but offered no added ben­e­fit,” and sug­gested that guide­lines for rec­om­mend­ing fish oil sup­ple­ments need to be revised.

Haley Hughes, reg­is­tered dietit­ian and cer­ti­fied dia­betes edu­ca­tor with RDRx Nutrition told Olive Oil Times, ​“As a dietit­ian, I pro­mote food first vs. sup­ple­men­ta­tion in most cases. This study along with many oth­ers sup­ports that obtain­ing nutri­tion from food sources vs. sup­ple­ments is impor­tant to achieve opti­mal health and pre­vent dis­ease. Before jump­ing right into pre­scrib­ing fish oil sup­ple­ments, I rec­om­mend incor­po­rat­ing more Mediterranean diet lifestyle choices includ­ing using olive oil for cook­ing, hav­ing fish 2 – 4 times a week, increas­ing activ­ity, etc. However, call­ing olive oil a placebo, in my opin­ion, is crazy. We know it’s one of the most potent car­dio-pro­tec­tive and anti-inflam­ma­tory food sources.”

A study pub­lished ear­lier this year also raised doubts over the effec­tive­ness of omega‑3’s fatty acids in reduc­ing car­dio­vas­cu­lar risk. The study showed they had almost no effect on either car­dio­vas­cu­lar health or mor­tal­ity rates.

A 2017 report con­cluded that a Mediterranean diet rich in olive oil could ben­e­fit car­dio­vas­cu­lar health in a num­ber of ways; back­ing up results of a 2014 study which con­firmed that reg­u­lar con­sump­tion of olive oil is ben­e­fi­cial to heart health.

While the debate over the ben­e­fits of fish oil for improv­ing human health con­tin­ues, it has been reported that olive oil extract is ben­e­fi­cial to the health of farmed fish and shows promise as an ingre­di­ent in aqua feed.

• New England Journal of Medicine