Omega 3 and vitamin D fail to protect against heart attacks or cancer in major trial which show supplements a 'waste of time'

Experts warn biggest effect might be giving users 'very expensive urine'

The biggest trial to date of vitamin D and omega 3 fish oil supplements taken by millions to stave off ill health has concluded they do nothing to reduce heart attacks, strokes or cancer.

Those over 50 who were otherwise healthy and taking one or both supplements experienced the same number of heart disease related events and invasive cancers as those who were taking a placebo each day, Harvard University researchers found.

Health experts said they hoped the findings would counteract the claims of some of the most widely used supplements and stop the public thinking the pills can be a quick fix to mitigate the impact of poor diet and unhealthy lifestyles.

“By and large the marketing of supplements is done very cleverly, but it’s not backed up by evidence,” Naveed Sattar, a professor of metabolic medicine at the University of Glasgow, told The Independent.

“Most people buying supplements are giving themselves very expensive urine. They’re wasting their time and getting false reassurance of protection from these supplements, when what they need is help to look at improving their lifestyles in ways which are enjoyable and sustainable.”

However, a second trial, also published in the New England Journal of Medicine, suggests there may yet be a use for fish oils, but only when concentrated to a level more closely found in pharmaceutical drugs and given to patients most at risk of heart disease.

Vitamin D is an essential nutrient that helps lock calcium in bones and is particularly important in childhood and pregnancy.

It can be obtained through diet or the body can also produce it from sunlight, though this is often lacking in modern, office-bound life, and vitamin D deficiency is widespread in parts of the northern hemisphere with less sunlight.

This deficiency has been associated with higher levels of cancer and heart disease, but vitamin D levels are also lowest in people who smoke, are more obese and have other factors that increase their risk.

The picture is similarly unclear for omega-3 fish oils – the world’s most popular supplement, which has been touted as helping to boost brain power, protect from heart disease and reduce deaths from all causes.

The Harvard trial, known as Vital, sought to settle the question of what benefits the public might gain from these supplements, and found nothing in their favour.

In the trial, 26,000 healthy over-50s took either double their minimum daily requirement of vitamin D, 1g of fish oil equivalent to the dose recommended by the American Heart Association for people with a risk of heart disease, or both.

After five years there were more than 805 heart attacks, strokes or other cardiovascular events, and 1,617 cancers diagnosed, but these were split virtually in half between the groups.

“In the absence of additional compelling data, it is prudent to conclude that the strategy of dietary supplementation with either n-3 fatty acids or vitamin D as protection against cardiovascular events or cancer, suffers from deteriorating Vital signs,” an independent editorial published alongside the study concludes.

Professor Sattar’s conclusion was similar.

Don’t waste your time on vitamin D,” he said. “There are thousands of people still popping it, but this is the biggest trial in the world to date, so forget vitamin D, draw a line under it.”

However he said that a second large trial, the REDUCE-IT study, involving universities across the US has suggested there could still be uses for omega-3, just not in the dose you buy on the high street.

It looked at a concentrated dose of a particular fish oil, called eicosapentaenoic acid (EPA) in a much more concentrated form, equivalent to four to eight times the dose in the Vital trial.

The study also focused on patients who already had heart disease, or a high risk of developing it because of conditions like diabetes, as well as high cholesterol not controlled by their statin medication.

After following more than 8,000 high risk adults for five years the trial found serious cardiovascular events were reduced as much as 25 per cent and deaths fell 20 per cent.

“It doesn’t show any benefit in relatively healthy people, so you would think fish oils were done too,” Professor Sattar said. “But the size of this benefit is substantial – for this specific dose in this specific group of people.

“It’s one trial but it really bucks the trend.”