Recently, research studies done on the usefulness of the fish oil and vitamin D for heart show evidence of contrasting reports and are inconclusive. A clinical trial done at Brigham and Women’s Hospital with the collaboration of National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH) , concluded that “Both the trials were negative”. “Neither fish oil nor vitamin D actually lowered the incidence of heart disease or cancer” according to Dr. Lawrence Fine, chief of the clinical application and prevention branch of the NHLBI.
These results were presented at the American Heart Association Scientific sessions 2018 held at Chicago. The original articles on “Vitamin D supplements and Prevention of Cancer and Cardiovascular Disease” and “Marine n-3 fatty acids and Prevention of Cancer and Cardiovascular Disease” were published in The New England Journal of Medicine. The VITamin D and Omega- A 3 triAL (VITAL) is a clinical trial including a study population of 25,871 U.S. adults (men aged ≥50 and women aged ≥55), without cardiovascular disease or cancer with an oversampling of 5106 African Americans.
Vitamin D at a dose of 2000 IU per day and marine n-3 fatty acids (omega 3 fatty acids)at a dose of 1g per day were given to some of the participants, while others consumed the same dose of Vitamin D plus placebo. Some participants consumed the same dose of fish oil and placebo, whereas the last group ingested the two placebos. Follow up after more than 5 years was taken for the participants.
Although the overall results were disappointing, fish oil appeared to have beneficial effects on prevention of heart attacks. Supplementation with fish oil did not result in lowering the incidence of major cardiovascular events or cancer than the placebo.
Primary outcome measures of the study were the assessment of major cardiovascular events such as myocardial infarction, stroke or death from any cardiovascular disease and any type of cancer. Secondary outcome measures of the study were the assessment of expanded cardiovascular events such as coronary artery bypass grafting etc and site- specific cancers and death from cancers.
According to Dr. JoAnn E. Manson (Chief of the division of preventive medicine at Brigham and Women’s Hospital), who led the research, a secondary analysis showed that taking fish oil or omega 3 fatty acids lowered the risk of heart attack by about 28 percent and this is “statistically significant” finding.
The people who were benefited the most were the ones who didn’t ordinarily eat much fish in day- to- day diet as well as African- Americans, according to Dr. Manson.
Analysis of Omega 3 supplementation trials involving adults who had cardiovascular disease or who were at high risk for cardiovascular disease have shown that supplementation has no, or at most a weak, preventive effect on cardiovascular diseases. Indeed, a greater benefit of the omega 3 supplementation on the cardiovascular events was observed among the participants without a history of stroke and among those without a history of cardiovascular disease in the trial than among those with such histories.
The hypothesis that supplementation with n-3 fatty acids (fish oil) confer cardiovascular protection is biologically plausible. Data from animal studies, laboratory studies as well as small clinical trials on humans, support mechanisms including antithrombotic, blood pressure lowering, bad cholesterol level lowering (hypotriglyceridemic), anti-inflammatory effects, promotion of nitric oxide induced endothelial relaxation etc, whereby n-3 fatty acids may reduce risk.
According to this clinical primary- prevention trial, supplementation with vitamin D3 did not lead to a significantly lower incidence of cancer of any type or a major cardiovascular event as well as death from any type of cancer. Also, the use of vitamin D, did not lead to a significant difference in secondary outcome measures.
No serious side effects such as bleeding, high blood calcium levels, gastrointestinal symptoms etc, were observed with either of the supplement.
In the meantime, Dr. Fine, NIH official, says that “don’t throw out your fish oil or vitamin D3 supplements”. If one is thinking about any of these supplementation, take consultation from the physician or health care provider. Although vitamin D and omega 3 fatty acids found in the fish oil supplements are important nutrients, but the best way to get these nutrients is as a part of a well-balanced diet. A well-balanced diet includes fatty fish such as sardines, salmon and tuna etc and vitamin D- fortified milk, cereals and juices.
Another study published recently in The New England Journal of Medicine, by Dr. Deepak Bhatt et al, examined the effects of icosapent ethyl (a highly purified eicosapentanoic acid ethyl ester, a component of fish oil) on lowering triglycerides levels and cardiovascular risk reduction.
Patients with elevated triglyceride levels are at increased risk for ischaemic and other cardiovascular events. Icosapent ethyl, lowers triglyceride levels. According to the above mentioned study, the risk of cardiovascular death, heart attack, stroke etc was significantly lower, by 25 percent, among those who received 2g of icosapent ethyl twice daily than among those who received placebo. In their study, they also concluded that patients with elevated triglyceride levels who were receiving statin therapy, the risk of major ischaemic events eg cardiovascular death, was significantly lower with icosapent ethyl than with placebo.
This study was supported by Amarin Pharma and the product is available for the patients with high triglycerides, by prescription only. The company is expected to apply for FDA approval to expand treatment to include all the high- risk cardiovascular patients.
There are a lot of side effects of fish oil so the negative impact on heart is also possible.