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.
The study provides much-needed clarity regarding the benefits of fish oil supplements for people with diabetes but no history of cardiovascular disease.
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.