Study finds butter safer than margarine for health

A large new review of existing research has found no link between saturated fat in diet of healthy people and any health risk.

On the other hand, trans fats, have been linked to an increased risk of death generally, death from cardiovascular disease and coronary heart disease.

In other words, butter was fine but too much margarine could be deadly.

As per recommendations, saturated fats, found in animal products like butter, egg yolks and salmon, should not comprise over 10 per cent of daily calories, while trans unsaturated fats, or trans fats, like the hydrogenated oils that keep processed foods and margarine shelf-stable, are primarily industrially produced and should not provide more than 1 per cent of daily calories.

The new review, drew on research from many Canadian institutions including McMaster University in Hamilton, Ontario, data from 41 studies of the association between saturated fat intake and health outcomes, that covered over 300,000 people, as also 20 studies of trans fat intake and health outcomes that included 200,000.

Saturated fat intake was linked to any coronary heart disease, cardiovascular disease, stroke or type 2 diabetes, but its link to risk of death from coronary heart disease remained unclear.

As against this, industrial trans fats consumption was associated with a 34 per cent rise all-cause mortality, a 28-per cent increased risk of heart disease mortality and a 21 per cent increase in the risk of heart disease, the study team reported in The BMJ.

People have traditionally been advised to cut animal fats, but the biggest ever study had shown they do not up the risk of stroke, heart disease or diabetes.

However, trans fats, found in processed foods such as margarine, could raise the risk of death by 34 per cent in less than a decade.

"For years everyone has been advised to cut out fats," said study lead author Dr Russell de Souza, an assistant professor in the Department of Clinical Epidemiology and Biostatistics, at McMaster University in Canada.

"Trans fats have no health benefits and pose a significant risk for heart disease, but the case for saturated fat is less clear.

"That said, we aren't advocating an increase of the allowance for saturated fats in dietary guidelines, as we don't see evidence that higher limits would be specifically beneficial to health."

The "vilification" of saturated fats dated back to the 1950's when research suggested a link between high dietary saturated fat intake and deaths from heart disease. However, the author of the study considered data from only six countries, and ignored data from a further 16 that did not fit with his hypothesis.

In 2013, declaring a war on trans fats, the US Food and Drug Administration said, it would require food makers to gradually phase out artificial trans fats (See: US FDA to phase out trans fats from food on health concerns).