Butter vs Margarine: Which Is Healthier?

Chapter summary

Butter got bad press when the advice was to cut fat and avoid saturated fat. The author says butter is a healthy fat and the body needs healthy fat.
Polyunsaturated fats from vegetable oils are linked to allergies and other problems.
Avoid margarine during pregnancy and for at least the first three years of a child’s life.
Use butter, not margarine.

It was invented in the 19th century as a cheap butter substitute, for people who could not afford butter and for soldiers in the field.
It can be made from animal fat or vegetable oil, but most today is made from plant oils.
Plant oils have less of three saturated fatty acids (16:0, 14:0 and 12:0) and no cholesterol, so margarine was promoted as better for the heart.

Margarine is made by hydrogenation: heating oil and adding hydrogen gas. The more hydrogenation, the more solid it becomes.
The heat converts some natural cis bonds into trans bonds. Trans fats are a known health risk.
Modern manufacturing lowers trans fat, but the product is still heavily processed.

Finnish and German studies found children who eat more margarine have double the rate of diagnosed eczema, hay fever, allergies and asthma.
Early childhood, before age three, is when these allergies develop.
If the mother ate margarine or vegetable oils in the last four weeks of pregnancy, children had at least a 50% higher chance of eczema, hay fever or allergies.
Allergy risk tracks the level of polyunsaturated fat in the placenta and cord blood. A Swedish study found high levels of both omega-3 and omega-6 in cord blood predicted allergy.

Heart advice: Many heart organisations still recommend spreads made from plant oils because they contain less saturated fat.
The author’s view: The saturated fat and heart disease link is weaker than stated, and margarine carries processing and allergy risks.
Study limits: The allergy evidence is observational, and reports link diet with allergy but cannot prove cause. Some studies found no effect for margarine on allergy.

A margarine: water, vegetable mono- and diglycerides, salt, rice starch, gelatin, natural and artificial flavours, lactose, colours (yellow 5 and 6), emulsifier, preservatives, soy lecithin and vitamin A.
Butter: milk, cream and sometimes salt.

Barman, M. et al. (2013) High levels of both n-3 and n-6 long-chain polyunsaturated fatty acids in cord serum phospholipids predict allergy development. PLoS ONE 8(7):e67920.
Sausenthaler, S. et al. (2007) Maternal diet during pregnancy in relation to eczema and allergic sensitization in the offspring at 2 y of age. Am J Clin Nutr.
Sausenthaler, S. et al. (2006) Margarine and butter consumption, eczema and allergic sensitization in children. Epidemiology.
Dunder, T. et al. (2001) Diet, serum fatty acids, and atopic diseases in childhood. Allergy 56(5):425-428.
von Mutius, E. et al. (1998) Increasing prevalence of hay fever and atopy among children in Leipzig, East Germany. Lancet 351:862-6.
Gillespie, D. (2013) Want kids with allergies and asthma? Feed them margarine.