The next time you head for the nearest fast food joint think twice before ordering your favourite burger, as a new research has revealed that just one meal high in saturated fat can affect the body's ability to protect itself against some of the underlying causes of heart disease and stroke.
The research, conducted at The Heart Research Institute in Sydney, Australia, appears in the August 15, 2006, issue of the Journal of the American College of Cardiology.
According to the study, even a single meal high in saturated fat can reduce the ability of the body's "good" cholesterol, or high-density lipoproteins (HDL), to protect the inner lining of the arteries from inflammatory agents that promote the formation of artery-clogging plaques.
A single high-fat meal also can affect the ability of the arteries to expand in order to carry adequate blood to tissues and organs.
On the other hand, according to the research, eating a meal high in polyunsaturated fat, a healthier form of fat, can increase the anti-inflammatory properties of HDL, helping to protect the inner lining of the arteries, called the endothelium, from plaque buildup.
"The take-home, public-health message is this: It's further evidence to support the need to aggressively reduce the amount of saturated fat consumed in the diet," said researcher Stephen J. Nicholls, MB, BS, PhD, now a cardiologist at Cleveland Clinic in Ohio.
"This study helps to explain the mechanisms by which saturated fat supports the formation of plaques in the arterial wall, and we know these plaques are the major cause of heart attack and stroke."
Saturated fats are found in both animal and plant products, and typically are solid at room temperature.
Examples include butter, lard and palm oil. The American College of Cardiology and the American Heart Association recommend that people limit their intake of saturated fat to no more than 7 per cent of their total daily calories. Polyunsaturated fats, on the other hand, come mainly from plants and are liquid at room temperature. Examples include sunflower and corn oil.
"In putting this all together," Dr. Nicholls said, "we have a difference between the two meals regarding a number of factors that influence the early stages of plaque formation. We have a situation where consumption of a single meal containing a high level of saturated fat is associated with impairment of vascular reactivity and impairment of a normal protective property of HDL. In contrast, consumption of a meal high in polyunsaturated fat results in HDL that is more protective.
"It is a small study," he concluded, "but I think the findings have broad implication because diet and exercise are the cornerstones of all strategies for preventing heart disease."