According to the Nurses’ Health Study the single biggest dietary predictor of heart disease was consumption of margarine. Eating 4 teaspoons of margarine increased the risk of heart disease in women by 50% compared with those who ate margarine rarely.
Trans-fats have been linked to increased risk of coronary heart disease and cancer. Margarine is extremely high in trans-fats created during the process of hydrogenation. Though “trans-fat free” margarine is available, they are allowed to contain 5% trans-fats and still carry that label. However, an interesting research project would be to see if the relative drop in trans-fat levels in margarine is correlated with the recent drop in coronary heart disease in the US.
Until 1950, in the US, adding yellow dyes to margarine was illegal but such restrictions were rescinded in the Margarine Act of 1950 which allowed margarine to be dyed yellow to look like butter.
For further reading:
- Intake of trans fatty acids and risk of coronary hear… [Lancet. 1993] – PubMed – NCBI
- JSTOR: Epidemiology, Vol. 8, No. 2 (Mar., 1997), pp. 144-149 – Margarine Intake and Subsequent Coronary Heart Disease in Men
- A Response to the National Association of Margarine Manufacturers – Weston A Price Foundation
- Welcome to the Nurses’ Health Study | Nurses’ Health Study
- Margarine is linked to lower intelligence – Health news – NHS Choices