Dietary factors in the fall in coronary heart disease mortality.

The role of dietary change in the fall in heart disease mortality has been hotly debated. Three countries, Australia, USA and UK with equal 'care' and sophistication of surgical techniques have shown different timing in the beginning of the decline of this 'epidemic'; around the mid 1960s in the first two countries, but not until the late 1970s for the UK. The cause of this difference may be the changing food habits of their populations. Using food disappearance data, apparent consumption of butter and margarine show opposite trends (butter down and margarine up) predating the decline in mortality in both the USA and Australia by at least 7 years and also in the UK, but at a later time, (about 1970). Changes in adipose tissue linoleate, a marker for polyunsaturated fat intake, support this indirect evidence, with depot levels rising in the USA from the 1960s and 10 years later in the UK. Other evidence support the view of decreasing saturated fat intake and increasing polyunsaturated intake prior to 1960 in the USA. Although many factors must contribute to the decline in mortality from CHD, change in dietary P/S ratio would seem to be the major dietary contributor.