Scientists have found a strong link between atherosclerosis - the clogging of the blood vessels - and the type of fat found in a typical "western" diet.

Dr Illona Staprans and a team from the VA Medical Centre in San Francisco warn that anyone who eats a lot of processed or fried foods increases the risk of having a heart attack.

Wrong kind of fat

Not only are burgers, fries, eggs and dairy products high in fat, they are high is the worst kind of fat called oxidised fat. This is made in the body when cholesterol comes into contact with free radicals, the highly reactive oxygen molecules that circulate in the blood and damage tissues.

The fat particles combine with the reactive oxygen and play a major role in the formation of the deposits which block blood vessels.

It has been suspected for some time that this process takes place in the body, but only now has it been tested in the laboratory. The results have been published in Atherosclerosis, Thrombosis and Vascular Biology: Journal of the American Heart Association.

Fatty streaks

The San Francisco team examined two sets of rabbits with a similar genetic make-up. One set was fed higher amounts of oxidised cholesterol and on examination 12 weeks later had twice as many fatty streaks on their arteries.

"Western diets contain high concentrations of oxidised cholesterol products, and our results suggest that these foods may be a risk factor for atherosclerosis," the report read.

"With the popularity of fried foods and the widespread fast-food industry, oxidised fats are common in the Western diet and could contribute to heart disease," Staprans added in a statement issued by the American Heart Association.