Taking fish oil pills really could stave off a heart attack, according to new research.
A study of almost 26,000 people found those who popped a daily capsule were much less likely to fall victim.
The supplements were “associated with significant reductions in heart attacks,” say the US team.
The Vitamin D and Omega-3 Trial (VITAL) showed healthy people who took a fish oil suffered fewer heart attacks – particularly if they did not regularly eat fish.
Lead author Dr JoAnn Manson says it adds to evidence omega 3 fatty acids found in oily fish like salmon, sardines or tuna boost the heart.
The take home message is to “eat fish”. People who don’t should consider a fish oil supplement – after consulting their doctor first.
The benefit was only seen in those who ate less than one-and-a-half servings of fish per week – which was the average level of consumption.
There was no added protection when dietary intake of the healthy fish oils, known as omega-3 fatty acids, was above this amount.
The study also identified a link between vitamin D pills and a reduction in the number of deaths from cancer.
In the UK one-in-five people become deficient in the ‘sunshine vitamin’ in autumn and winter when the nights draw in.
Although the nutrient is contained in some food it’s difficult to get the recommended daily 10 micrograms (400IU).
Dr Manson, of Brigham and Women’s Hospital in Boston, said: “The pattern of findings suggests a complex balance of benefits and risks for each intervention and points to the need for additional research to determine which individuals may be most likely to derive a net benefit from these supplements.”
VITAL is the first large-scale, rigorous controlled study to investigate how omega-3 supplements may affect heart disease risk in healthy people.
Men and women aged 50 and older were randomly assigned to take one gram of fish oil or 2,000 IUs (International Units) of vitamin D daily, or a placebo.
The fish oil supplements reduced risk of heart attack by 28 percent over the follow-up period. But they did not affect risk of stroke or cancer.
All volunteers took their assigned nutrients for approximately five years. The researchers tracked cancer diagnoses, heart attacks and strokes as well as deaths from cancer and cardiovascular disease.
Dr Manson said: “After more than five years of study and treatment, the results show promising signals for certain outcomes.
“For example, while omega-3 fatty acids (fish oil) showed only a small, but non-significant, reduction in major cardiovascular (CVD) events, they were associated with significant reductions in heart attacks.
“The greatest treatment benefit was seen in people with dietary fish intake below the cohort median of 1.5 servings per week but not in those whose intake was above that level.”
She added: “In addition, African-Americans appeared to experience the greatest risk reductions.”
Her team found they lowered their risk of heart problems more than whites taking the fish oil supplements.
That finding remained regardless of how much fish the African-American volunteers ate.
It suggests some possible genetic reasons for why African-Americans may benefit more from omega-3 fatty acids.
Dr Manson says this is important as blacks tend to have a greater risk of heart disease than whites and other racial groups.
The NHS advises that people should eat two portions of fish a week – including at least one of oily fish because of its high levels of omega-3.
Many people, however, do not eat oily fish and so choose supplements instead. An estimated £60 million is spent on omega 3 supplements in Britain every year.
The supplements are sold as capsules, pills and oils, available without a prescription in supermarkets, pharmacies and corner shops.
The results presented at a meeting of the North American Menopause Society (NAMS) in Chicago also found vitamin D supplements did not reduce heart attacks strokes or cancer.
But they were “associated with a statistically significant reduction in total cancer mortality among those in the trial at least two years,” said Dr Manson.
Vitamin D is made in the skin by the action of sunlight and this is the main source for most people.
Dr Manson and colleagues combined the studies of vitamin D and omega-3 fatty acids because they are not known to interact with each other in significant ways that would affect health outcomes.
VITAL allowed her group to study both nutrients in an efficient way for their effects on heart disease and cancer, two chronic diseases that affect a large proportion of the population.
Dr Stephanie Faubion, medical director of NAMS, said: “With heart disease and cancer representing the most significant health threats to women, it’s imperative we continue to study the viability of options that prevent these diseases and help women survive them.”
The debate over fish oil pills has raged for years. Last year a study of over 100,000 people by the British charity Cochrane found little proof they prevented heart disease.
They said the chance of getting any meaningful benefit from taking omega-3 is one in 1,000. But eating oily fish was recommended as part of a healthy diet.
The NHS says people should try to eat two portions of fish per week, one of which should be oily fish, such as salmon, fresh tuna or mackerel, to get enough “good” fats.
Around one in seven Brits take fish oil pills daily – believing they protect against heart attacks, arthritis and even dementia.
The global market is estimated to be worth £23 billion a year.