Fish Oil may Help to Prevent Heart Attacks

Atlantic Salmon

According to a very large VITAL randomized trial, taking supplemental fish oil may help to prevent heart attacks in people whose consumption of fish is low. The results were also especially good for African-Americans. This study carried out by researchers at Brigham and Women’s Hospital, an affiliate of Harvard Medical School, in Boston, Massachusetts was published January 3, 2019, in the New England Journal of Medicine.

Trial Examined Effects of Taking Supplemental Vitamin D and Omega-3 Fish Oil

The researchers examined the effects of taking supplemental Vitamin D (2000 IU) and supplemental Omega-3 fatty acid in fish oil (1 gram) to see if they could help prevent cancer or cardiovascular events. There were 25,871 participants in the trial (12,786 men aged 50 and older and 13,085 women age 55 and older). The participants were followed for about 5.3 years.

Vitamin D


During the trial, 793 cases of cancer were diagnosed among the 12,927 participants who had been assigned to take supplemental Vitamin D, as compared to 824 cancers diagnosed among those who had been assigned a placebo. This was too small a difference to be significant in the general population. However, African-Americans assigned to Vitamin D experienced a 23% reduction in the occurrence of cancers and further research is needed to confirm this.

Vitamin D also did not stop breast, prostate or colorectal cancers from occurring in people. However, there was a significant 25% reduction in the numbers of people who died from cancer.

Cardiovascular Disease

There were 396 major cardiovascular events such as heart attacks, strokes or cardiovascular death in the Vitamin D group in comparison with 409 in the placebo group, which appeared to be a small but insignificant reduction. The supplemental Vitamin D did not lower the occurrences of stroke, heart attack or cardiovascular death and it did not reduce the risk of death from any cause.

Side Effects

There were no significant increases in calcium in the blood, kidney stones or gastrointestinal problems from the supplemental Vitamin D.

Omega-3 Fatty Acids


There were 820 cancers that developed among participants in the omega-3 fatty acid group compared to 797 in the placebo group. This was a small but not significant difference. Omega-3 did not reduce the occurrence of breast, prostate, colorectal cancers or cancer related deaths or deaths from any cause.

Cardiovascular Disease

Omega-3 fatty acid from fish oil did not reduce risk for a major cardiovascular event in the overall study population.
During the trial there occurred 386 major cardiovascular events among the 12,933 participants who received the omega-3 fatty acids, as compared with 419 cardiovascular events among the 12,938 participants who received a placebo. The 8% reduction in cardiovascular events did not at first appear significant, but a closer look showed the reduction was only for heart attacks, but not for strokes.

People who had Low Consumption of Fish

However, omega-3 fatty acid did reduce the risk for cardiovascular events by 19% and specifically reduced the risk for heart attacks by 40% in people with low consumption of fish. There was also seen a trend toward a reduction in death from any cause and there was no increased risk for cancer.

People who had High Consumption of Fish

There were no benefits shown for people who regularly had a good consumption of fish in their diet (1.5 servings per week). Omega-3 supplementation did not protect them against cardiovascular events, heart attacks or death from any cause. It also did not protect them against cancer and in fact, they showed a slight increase in risk for cancer.


Omega-3 reduced risk of heart attacks in African-Americans by 77% regardless of the amount of fish in their diet.

Side Effects

There was no increase in bleeding or gastrointestinal problems in those who were assigned the omega-3 fatty acids from fish oil.

More Research is Needed

Supplementing with Vitamin D does not appear to have benefits for lowering risks for cardiovascular events or preventing cancer in the general population and so it is not necessary to take Vitamin D if you have sufficient amounts of it. A simple blood test can determine if you are low or have insufficient amounts of Vitamin D.

However, African-Americans who took supplemental Vitamin D showed a decreased risk for cancer and this needs to be confirmed with further research.

At this point it appears that supplementation with fish oil is not necessary for people who have an adequate amount of fish in their diet. Oily  fish like herring, sardines, mackerel and salmon have the highest amounts of Omega-3 fatty acids. Fish oil does appear to be beneficial for people who have a low consumption of fish in their diet. Fish oil also appears to be very beneficial for African-Americans regardless of the amount of fish consumed in their diet.

The researchers stress that more research is needed to confirm that some of these results are really beneficial and did not just occur by chance.

Park Crescent Healthcare and Rehabilitation Center in East Orange, New Jersey

If you or your loved one are in need of short-term rehabilitation as a result of a stroke or heart attack, the Park Crescent Healthcare and Rehabilitation Center in East Orange, New Jersey is a leading center for short-term rehabilitation and sub-acute care.


Heart Disease and cancer are the two leading causes of death in the United States and so it may be beneficial for people who do not get enough fish in their diet to supplement with Omega-3 fatty acids found in fish oil, as they were found to have lower risks for heart attacks. African-Americans had the best results from supplementing with fish oil regardless of how much fish they consumed in their diet and African-Americans also showed a decreased risk for cancer with Vitamin D supplementation. However, the researchers say that more trials are needed to confirm all of these results to make sure they did not just occur by chance.


Leave a Comment