London - The saturated fats found in meat and dairy produce are not as bad for health as previously believed, research has confirmed - but scientists have warned against gleefully reaching for the butter dish.
A major study into the health implications of dietary fats has failed to find a link between food containing saturated fats, such as eggs, chocolate and cream, and an increased risk of dying from heart disease, stroke or type-2 diabetes.
The study nevertheless did find that industrially produced “trans fats”, made from hydrogenated oils and once used in margarine, snacks and packaged baked foods such as some cakes and crisps, are linked with a greater risk of death from coronary heart disease.
The latest findings, published in the British Medical Journal, appear to confirm what has been a growing realisation that the prevailing health advice for the past a half century, to cut down on foods that are rich in saturated fats such as butter and cheese, may have been misguided.
The Canadian study, carried out by Dr Russell de Souza and colleagues at McMaster University in Hamilton, Ontario, found no association between saturated fats and ill health but did find a link with the consumption of foods containing trans fats, such as margarine.
The scientists found that the consumption of industrial trans fats was associated with a 34 percent rise in all causes of mortality, a 28 percent increase in death from coronary heart disease and a 21 percent rise in the risk of being diagnosed with heart disease.
Despite the failure to establish a link between the risk of ill health and premature death from eating foods containing saturated fats, Dr de Souza warned against taking these findings as a green light to eat more dairy foods, meat, eggs and milk chocolate - all rich in saturated fats.
“For years everyone has been advised to cut out fats. Trans fats have no health benefits and pose a significant risk for heart disease but the case for saturated fat is less clear,” he said.
“We aren't advocating an increase in the allowance for saturated fats in dietary guidelines, as we don't see evidence that higher limits would be specifically beneficial to health.”
Current dietary guidelines recommend that saturated fats are limited to less than 10 percent of daily energy intake, and trans fats to less than one percent to reduce the risk of heart disease and stroke.
The latest findings confirm the conclusions of five previous systematic reviews of the supposed links between coronary heart disease and saturated fats and trans fats but Dr de Souza said changing dietary guidelines is still not warranted.
“We could not confidently rule out an increased risk of death from heart disease with higher amounts of saturated fat and we should not ignore stronger and consistent evidence from better-designed studies that eating less saturated fat and more polyunsaturated fat from vegetable oils reduces 'bad' cholesterol levels, and that diets that replace saturated fat with these fats, as well as whole grains, reduce the chance of developing or dying from heart disease,” he told The Independent.
Tom Sanders, emeritus professor of nutrition at King's College London, said that the latest study should come with its own health warning as it largely relied on peoples' memories of what they ate some time ago, which are notoriously unreliable.
Trans fats were largely removed from the UK food chain 10 years ago, he pointed out, while the intake of saturated fats has fallen by about 40 percent since the 1970s and polyunsaturated fats found in vegetable oil and fatty fish have increased by 50 percent.
“It would be foolish to interpret these findings to suggest that it is okay to eat lots of fatty meat, lashings of cream and oodles of butter,” Professor Sanders said.
Dr Louis Levy, Head of Nutrition Science at Public Health England, said of the report's findings on higher levels of saturated fat: “Trans fats are harmful to health but in the UK consumption is already well within recommended levels and falling. The bigger issue is that we are all eating too much saturated fat which, as this study confirms, is linked to an increased risk of heart disease. That's why official advice is to reduce saturated fat in the diet to no more than 10 per cent of daily calories.”
FATTY FOODS
Good foods (containing unsaturated fats)
The “Mediterranean diet”, olive oil, fruit and vegetables, oily fish such as mackerel, herring, and sardines.
Not so bad foods (containing saturated fats)
Butter, cheese, cow's milk, eggs, bacon, red meat and chocolate
Bad foods (containing trans fats)
Food experts insist that trans fats were mostly removed from the UK food chain 10 years ago. Some biscuits, buns, cakes, pastries, margarines and spreads made using partially hydrogenated fats and oils may still contain them, as well as chips, burgers, kebabs and meat pies.
The Independent