Increasing dietary polyunsaturated fats and decreasing saturated fats is associated with an increase in both overall death rates and heart disease death rates

This study was published in the British Medical Journal 2013 Feb 4;346:e8707

Study title and authors:
Use of dietary linoleic acid for secondary prevention of coronary heart disease and death: evaluation of recovered data from the Sydney Diet Heart Study and updated meta-analysis.

Ramsden CE, Zamora D, Leelarthaepin B, Majchrzak-Hong SF, Faurot KR, Suchindran CM, Ringel A, Davis JM, Hibbeln JR.
Laboratory of Membrane Biophysics and Biochemistry, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA.

This study can be accessed at: http://www.ncbi.nlm.nih.gov/pubmed/23386268

The objective of the study was to evaluate the effectiveness of replacing dietary saturated fat with polyunsaturated fat, for the prevention of coronary heart disease and death in men with heart disease. The study lasted for 39 months and included 458 men, aged 30-59 years, who had had a heart attack or angina.

The men were allocated into two groups and instructed to either:
(i) Increase their polyunsaturated fat intake to about 15%, reduce their intake of saturated fat and to less than 10% and reduce their dietary cholesterol to 300 mg per day. To achieve these targets these men were provided with liquid safflower oil and safflower oil polyunsaturated margarine (high polyunsaturated fat group).
(ii) Carry on with their normal diet (saturated fat group).

The study found:
(a) After 12 months the cholesterol levels of the men on the high polyunsaturated fat diet were 8.5% lower than the men on the high saturated fat diet.
(b) Men who consumed the high polyunsaturated fat diet had a 62% increased risk of death compared to the men who consumed the high saturated fat diet.
(c) Men who consumed the high polyunsaturated fat diet had a 70% increased risk of death from cardiovascular disease compared to the men who consumed the high saturated fat diet.
(d) Men who consumed the high polyunsaturated fat diet had a 62% increased risk of death from heart disease compared to the men who consumed the high saturated fat diet.

The study shows that increasing dietary polyunsaturated fats and decreasing saturated fats is associated with an increase in both overall death rates and heart disease death rates.