Many years ago the chicken industry, faced with a backlash against all meats, hired an advertising agency. They came up with the word “white” meat. For years the industry has been attributing all sorts of benefits to chicken “white meat” – none of which are true. White meat is the same as red in every way – whether in cholesterol, oil or anything else that people want to avoid. But no matter what the scientists and food experts say, people will now continue to regard chicken as “aspirational” and good for their health.
The same goes for fish oil. Fish oil is now the third most widely used dietary supplement, after vitamins and minerals.
People have been told repeatedly through advertisements and doctors paid by the industry, that fish oil has Omega 3 and these fatty acids will protect their hearts. Fish oil has also been sold for preventing heart disease or stroke, as well as for clogged arteries, chest pain, irregular heartbeat, bypass surgery, heart failure, rapid heartbeat, preventing blood clots, and high blood pressure after a heart transplant.
The problem is, that most of the clinical trials involving fish oil have found no evidence of any of this. From 2005 to 2012, at least two dozen rigorous studies on fish oil were published in leading medical journals, most of which looked at whether it could prevent heart disease, attacks or strokes in high-risk populations (obese, low exercise, meat eating, smokers, history of heart disease, high cholesterol, hypertension or Type 2 diabetes). Twenty of these studies found that it had NO benefits at all.
In theory, fish oil supplements are rich in two omega-3 fatty acids – eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) — that could have a blood-thinning effect, much like aspirin, and could therefore reduce the possibility of clots. Omega-3s can, in laboratory findings, also reduce inflammation which helps in atherosclerosis. Supposedly they also increase blood flow, reduce blood pressure and give structural strength to neurons.
Unfortunately these properties of omega-3 fatty acids don’t translate into benefits for the human body. This is what all large clinical trials, done on thousands of people, have proven. A review in Journal of the American Medical Association (JAMA), involving almost 70,000 people, states that no compelling evidence was found to link fish oil supplements to a lower risk of heart attack, stroke or early death.
So where did this myth, that has made so many companies rich and wasted so much consumer money, come from? Research was carried out in the 1970s by Danish scientists Dr Hans Olaf Bang and Dr Jorn Dyerberg, who decided that Inuits living in Greenland had low rates of cardiovascular disease and they attributed it to an omega-3-rich diet consisting of fish, seal and whale blubber. This research was disproved by Dr George Fodor, a cardiologist at the University of Ottawa, who showed that Inuits had as much heart disease as any high risk population. But by then the fish oil industry was up and running!
In the 1990s an Italian study, which showed that fish oil was better than Vitamin E, was also exaggerated to bolster this theory. It prompted the American Heart Association to endorse fish oil as a way for heart patients to get more omega-3s in their diets.
The sales shot through the roof all over the world as heart patients sought this easy way. They decided not to exercise and compromise on eating, drinking or smoking but, to take supplements of fish oil and lie back. According to Professor Andrew Grey and Dr Mark Bolland, at the University of Auckland in New Zealand and the authors of a 2014 study on fish oil, “The sales are going up despite the progressive accumulation of trials that show no effect.”
Over the years similar findings have been published in the top-ranking internal medicine journals (New England Journal of Medicine, The Lancet, JAMA, PLoS Medicine, JAMA Internal Medicine, British Medical Journal, and Annals of Internal Medicine). If nothing else, doctors who read these journals should have atleast stopped recommending fish oil. But sales in America alone went up from $425 million in 2007 to $1,043 million in 2012. The same sort of increase was found in the United Kingdom and Australia (which also includes us!). 10 percent Americans now take a daily pill of fish oil. Some take it on the advice of their doctors, others because of its ready availability. Anecdotal evidence, supportive one sided “news” reports and selective presentations by the fish oil industry are other reasons which prompt people to consume fish oil.
A clinical trial of 12,000 people, done by Dr Gianni Tognoni of the Institute for Pharmacological Research in Milan, published in The New England Journal of Medicine in 2013 found that fish oil did not reduce the rate of death from heart attacks and strokes in people with evidence of atherosclerosis. “In fact, there has been a spate of studies showing no benefit,” said Dr James Stein, the director of Preventive Cardiology at University of Wisconsin Hospital.
In contrast, doctors warn that fish oil can be dangerous when combined with aspirin or other blood thinners, it can lead to bruises and nose bleeds. Preston Mason of the Harvard Medical School talks about the danger of fish oil in a widely watched documentary made for Frontline titled Supplements and Safety.
It comes down to oxygen, says Mason. Fish oil is extracted as a by-product from oily fish like anchovies. As the fish are crushed, they’re exposed to air, which means the oil becomes oxidized. Oxidized fish oil contains oxidized lipids, which can trigger changes inside human cells that can further lead to health problems like cardiovascular disease. Prescription-grade fish oil needs to be approved by the Food and Drug Administration, notes Mason. The risk of oxidation runs low because the approval process comes with stringent production standards. However, in Mason’s work and in other previously published studies, researchers have found that the type of fish oil that’s sold in stores often has high levels of oxidation.
In the early 2000s the fish oil market began to soar because of the favourable recommendations of the influential American Heart Association. When the association was asked for an expert to explain the recommendation, former AHA president Robert Eckel, said that the recommendation needs to be revised. “It would be a good time for that to be updated,” Eckel said. “Almost all studies of fish oil supplements show no benefit. I really feel this remains unproven.”
In the 1990s, a study came out in Wales linking fish oil intake with a longer life. In 2003, some of the researchers, who conducted the early and influential study, published the results of a follow-up. Of 3,000 Welsh men with angina – a chest pain caused by coronary heart disease – some were advised to eat oily fish or take fish oil supplements. This time they found that the fish group patients were more likely to die, and the researchers said it was particularly worse for those taking the fish oil pills. “The excess risk [of cardiac death] was largely located among the subgroup given fish oil capsules,” they reported.
So, while fish oil will not help remove any possibility of a heart attack, it may actually propel you towards one!
Sometimes I wonder why I should write these articles. What does the Drug Controller General of India even do?
First Published On : Jul 25, 2016 17:36 IST