Just when you thought you'd got it straight that trans fatty acids found in margarine can cause a heart attack, new research covering nine countries seems to put it in the clear.

The influential EURAMIC study, which covers eight European countries and Israel, suggests there is no conclusive evidence to show that margarine is linked to heart problems. But it does warn that there could be some connection in countries where there is a very high intake.

The finger was pointed at trans fatty acids in May, 1994 following a major Harvard study (see WDDTY, vol 5, no 4). The study reckoned that the acids accounted for 6 per cent of all heart disease deaths, or 30,000 Americans every year.

The study had the margarine manufacturers running for cover, and several introduced margarine with a new formula with a content of just 1.5 per cent of trans fatty acids.

Now the EURAMIC study is saying that the fuss was about nothing. It based its findings on two groups of men 671 with a serious heart condition, and 717 without any history of heart problems. They discovered that both groups had similar levels of trans fatty acids in their tissues. Their findings are in line with those reached by the National Cholesterol Education Program in the US in 1993, which said that "trans fatty acids do not raise cholesterol to the rate that saturated fat does".

Trans fatty acids are formed by the hydrogenation of vegetable and fish oils. They are found in margarine, chips, doughnuts and in vegetable oils contained in shortenings and biscuits (The Lancet, February 4, 1995).

While a high fat diet may increase the risks of several types of cancer, olive oil is apparently not one of the offenders. Researchers have found no evidence linking a diet high in olive oil with cancer. They point to the very low rate of breast cancer in Greece, where the average consumption of olive oil is 80g a day (ECP News, 1995; 27:8-9).