A growing numbers of Americans use vitamins and supplements to help protect their health and Fish Oil supplements are one of the most popular. A recent survey by ConsumerLab.com showed Fish Oil use second only to Vitamin D. Fish Oils contain omega-3 fatty acids that have been touted as offering protection against everything from Alzheimer’s Disease to cancer to arthritis. But it’s Fish Oil’s possible link to preventing heart disease that been the biggest reason for its popularity. But does Omega-3 actually protect against cancer and heart disease? A new study seems to indicate “NO” but a closer look at the data reveals some pretty strong evidence that there may actually be a protective effect that was missed in the overall analysis.
The Evolution of Omega-3 Supplementation
The idea that omega-3 supplements may help to protect against heart attacks had its origins in studies of Inuit tribes in the 1970’s. Living in the Arctic meant they didn’t farm fruits or vegetables and there were not may plants available to forage. So, their diet consisted mainly of whales, seals and fish. Yet despite having a diet made up mainly of fatty meats and fish, the Inuits had relatively low rates of heart attacks. The researchers concluded that high levels of omega-3 fatty acids found in fish were somehow protecting
the Inuits and this eventually led to the recommendation that the rest of us should start including Fish Oil supplements in our diets.
The flaw in that conclusion was that this was merely an observational correlation that didn’t prove a cause and effect relationship between high omega-3 intake and the low rates of heart disease. And subsequent studies published in 2015 showed that the ancestors of the Inuits had evolved unique genetic adaptations that changed the way they metabolized omega-3 fatty acids. So, rather than getting a protective advantage from their high intake of fish oils, they may have needed to change their metabolism just to cope with their fatty diet and some other factors may be the reason why they have lower heart attack rates than other populations.
The Study
Over the years, several research studies have tried to show a benefit from omega-3 supplementation but failed to prove a decrease in cardiovascular risk. The latest study, known as VITAL, was reported at the American Heart Association annual scientific convention in November, 2018. The VITAL study was designed to answer whether Vitamin D or Omega-3 supplements could prevent cancer or cardiovascular disease. The headlines from the conference trumpeted Omega-3 and Vitamin D as failures at preventing either cancer or heart attacks. It seemed like “game over” for the omega-3 supplement craze.
The Flaw
But buried in the data were some interesting suggestions of a substantial benefit from omega-3 supplements.
The study initially reported that there was no benefit from Omega-3 supplements because the endpoint of the study was a composite of heart attacks, strokes and cardiovascular mortality. Out of the nearly 26,000 study participants (half of whom took omega-3 and half got placebo), those events occurred in 386 people taking omega-3 supplements compared with 419 who were taking placebos. That was an 8% reduction but was considered a statistically non-significant difference.
It turns out that the reduction in overall events was almost entirely due to a reduction in heart attacks- strokes and other types of cardiovascular events were less affected. So, the overall data diluted the significance of some of the individual components. If you look at just the number of participants who ended up needing a stent during the study or had a heart attack the conclusions look very different:
• The rate of angioplasty and stent procedures was reduced by 22% in the omega-3 group
• The overall rate of heart attacks was reduced by 28% in the omega-3 group
• Even more importantly, the risk of a fatal heart attack dropped by 50% in the omega-3 group!
The most consistent cardiovascular benefits were found in those people who reported a low intake of fish at the start of the study and in African Americans. In those who reported less than 6 ounces of fish intake per week the study found:
• A 19% reduction in overall cardiovascular events with omega-3 supplementation
• A 40% reduction in heart attacks overall with a 77% reduction in heart attacks among African Americans!
In another study, known as REDUCE-IT, presented at the same conference a 25% reduction was seen overall major cardiovascular events. This is a much greater effect than was seen in the VITAL study.
Why the Difference?
The REDUCE-IT study used higher doses of omega-3 with 4,000 mg per day compared with 1,000 mg per day in the VITAL study. The REDUCE-IT trial also used icosapet-ethyl, a different form of omega-3 available as the prescription medication Vascepa. Omega-3 contains primarily two fatty acids: EPA and DHA. Vascepa is pure EPA. Additionally, the study population in the REDUCE-IT trial had elevated triglyceride levels in their blood which may mean they get a bigger risk reduction from the lowering of their triglycerides by omega-3 supplements.
Far from proving that omega-3 supplements do not help to prevent heart attacks, the VITAL and REDUCE-IT studies actually appears to show a substantial benefit. For those who are getting a sufficient amount of omega-3 in their diet, additional supplementation may not confer much advantage. But if you have a relatively low intake of fish in your regular diet, adding 1,000-4,000 mg per day of omega-3 supplements is likely to substantially reduce your heart attack risk.
