Fat Chance: Saturated Fats Have No Link to Heart Disease

Dairy-lovers and carnivores, rejoice. A new study has found that there is no association between a high intake of saturated fat and an increased risk of heart disease and other life-threatening diseases.

The study, published in the British Medical Journal on Wednesday, said that consumption of trans unsaturated fats—found in everyday supermarket goods such as margarine, processed cakes and microwave popcorn—can increase the risk of death from coronary heart disease (CHD) by 28 percent.

Higher consumption of saturated fats, which are mainly found in animal products such as dairy, meat and egg yolks, has no association with death for any reason, CHD or other cardiovascular diseases, stroke or type 2 diabetes, according to the study, led by researchers at McMaster University in Ontario, Canada.

The findings appear to fly in the face of prevailing medical advice. The NHS recommends that men should eat no more than 30g and women 20g of saturated fat per day and warns that those with diets that are high in saturated fat may have higher blood cholesterol, increasing the risk of heart disease. The American Heart Association says that 5-6 percent of daily energy intake should come from saturated fats—meaning that for someone with a calorie intake of 2,000 per day, just 120 calories should come from saturated fats, equating to about 13g. To put that in perspective—a McDonald's Big Mac hamburger has 9.5g of saturated fat.

Ahead of the most recent study, there have been others who have questioned the long-accepted link. A British cardiologist said that saturated fat had been "demonised" and that the food industry has overcompensated by replacing saturated fats with unhealthy sugars, in an October 2013 opinion piece in the British Medical Journal. A major review published in the Annals of Internal Medicine journal last March also claimed that evidence from 72 studies showed no significant link between saturated fats and heart disease risk.

Russell de Souza, a dietitian and nutrition epidemiologist at McMaster and the present study's lead author, says that the results show having an overall balanced diet is more important than just cutting out saturated fats. "It's important to get across that there's really no one nutrient or food which is responsible for all heart disease or diabetes or death, and that the whole diet matters."

However, he cautions that the study is just "one piece of the puzzle" and advises people to heed the body of evidence which shows that eating too much saturated fat is generally not a good idea. "I wouldn't recommend eating all the butter and cheese that you want at this point," he says.

The study involved an analysis of results from 50 observational studies which looked into the association between saturated and trans fats with health risks. The authors found that trans fats, which are mainly produced industrially from plant oils via a process called hydrogenation, pose a significant health risk. Trans fat consumption was associated with a 34 percent increase in death for any reason, as well as a 21 percent increase in the risk of developing CHD.

De Souza warns consumers to watch out for products which included hydrogenated or partially hydrogenated oils in their ingredients list—this indicates the presence of dangerous trans fats, which are often used to extend the shelf life of baked goods and processed foods. "With those products, you shouldn't eat them at all," says de Souza, warning that trans fats have the net effect of lowering good cholesterol and raising bad cholesterol. According to Reuters, the U.S. Food and Drug Administration (USFDA) has given food manufacturers until 2018 to remove trans fats from the food supply.