In the never-ending seesaw that is the science of nutrition, researchers have a new take on saturated fat.
At one point we were advised to cut out all fats. Then we were told about the “good” fats, which we were supposed to eat. Margarine was in, margarine was out. Eat this one, not that one. We need a flow chart to keep up with what we’re supposed to be doing in regard to lipids in our diets.
During most of the wavering, though, experts have stood steadfast against saturated fat – the ones that come from animal products, like butter, cows' milk, meat, and egg yolks. But even so, animal fats have always had their advocates. And now those cheerleaders are welcome to a hearty does of “told you so” if the latest study stands the test of time.
Conducted by researchers at McMaster University, the study concluded that while trans fats are associated with greater risk of death and coronary heart disease, saturated fats are not.
"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," said lead author Russell de Souza, an assistant professor in the Department of Clinical Epidemiology and Biostatistics with the Michael G. DeGroote School of Medicine.
"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."
Trans fats are mainly an industrial product made from plant oils in a process known as hydrogenation; they are used in margarine, snack foods and packaged baked goods. As the American Heart Association points out, trans fats are popular in food manufacturing because they are easy to use, inexpensive to produce and last a long time. Plus: they give foods a desirable taste and texture.
De Souza and colleagues were looking to clarify the confusion of prevailing dietary advice, especially after a recent evidence review found no excess cardiovascular risk associated with intake of saturated fat.
The team analyzed the results of 50 observational studies assessing the association between saturated and/or trans fats and health outcomes in adults. The researchers found no clear association between higher intake of saturated fats and death for any reason, coronary heart disease (CHD), cardiovascular disease (CVD), ischemic stroke or type 2 diabetes.
However, consumption of industrial trans fats was associated with a 34 per cent increase in death for any reason, a 28 per cent increased risk of CHD mortality, and a 21 per cent increase in the risk of CHD.
"If we tell people to eat less saturated or trans fats, we need to offer a better choice," says de Souza. "Unfortunately, in our review we were not able to find as much evidence as we would have liked for a best replacement choice.”
Until they do, feel free to adopt the AHA’s following advice to lower trans fat consumption – although who knows, things could change again.
- Eat a dietary pattern that emphasizes fruits, vegetables, whole grains, low-fat dairy products, poultry, fish and nuts. Also limit red meat and sugary foods and beverages.
- Use naturally occurring, unhydrogenated vegetable oils such as canola, safflower, sunflower or olive oil most often.
- Look for processed foods made with unhydrogenated oil rather than partially hydrogenated or hydrogenated vegetable oils or saturated fat.
- Doughnuts, cookies, crackers, muffins, pies and cakes are examples of foods that may contain trans fat. Limit how frequently you eat them.
- Limit commercially fried foods and baked goods made with shortening or partially hydrogenated vegetable oils. Not only are these foods very high in fat, but that fat is also likely to be trans fat.